Society for Ambulatory Assessment

Fourth quarter 2009 (October to December)

Adams P, Abela JR, Auerbach R, Skitch S. (Nov 2009). Self-criticism, dependency, and stress reactivity: an experience sampling approach to testing Blatt and Zuroff’s (1992) theory of personality predispositions to depression in high-risk youth. Pers Soc Psychol Bull, 35(11), 1440-51

S. J. Blatt and D. C. Zuroff’s 1992 theory of personality predispositions to depression posits that individuals who possess high levels of self-criticism and/or dependency are vulnerable to developing depression following negative events. The current study used experience sampling methodology to test this theory in a sample of 49 children ages 7 to 14. Children completed measures of dependency, self-criticism, and depressive symptoms. Subsequently, children were given a handheld computer that signaled them to complete measures of depressive symptoms and negative events at randomly selected times over 2 months. Results of hierarchical linear modeling analyses indicated that higher levels of both self-criticism and dependency were associated with greater elevations in depressive symptoms following negative events. Furthermore, each personality predisposition remained a significant predictor of such elevations after controlling for the interaction between the other personality predisposition and negative events. The results suggest that dependency and self-criticism represent distinct vulnerability factors to depression in youth.

Agarwal R, Light RP. (Dec 2009). The Effect of Measuring Ambulatory Blood Pressure on Nighttime Sleep and Daytime Activity-Implications for Dipping. Clin J Am Soc Nephrol. [Epub ahead of print]

BACKGROUND AND OBJECTIVES: Ambulatory blood pressure (BP) monitoring is commonly used to assess the circadian pattern of BP. Circadian BP pattern is influenced by physical activity and sleep cycle. The effect of BP monitoring itself on the level of physical activity and sleep remains unknown. If BP monitoring affects these parameters, then monitoring itself may influence the circadian BP pattern. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: To assess the effect of ambulatory BP monitoring on sleep duration, sleep efficiency, and daytime activity, we measured physical activity using wrist actigraphy in 103 veterans with chronic kidney disease. After 6 to 7 days of continuous activity monitoring, participants underwent ambulatory BP monitoring with simultaneous actigraphy. The above experiment was repeated after 1 mo. RESULTS: Among the top tertile of patients (most sleep), when wearing ambulatory BP patients spent less time in bed at night (−92 min, P < 0.0001), were less asleep during those hours (−98 min, P < 0.0001), and had reduced sleep efficiency (82% versus 77%, −5% P = 0.02). On the day of ambulatory BP monitoring, patients were more sedentary during waking hours (+27 minutes, P = 0.002). During ambulatory BP monitoring, waking after sleep onset more than median was associated with greater odds for nondipping (odds ratio 10.5, P = 0.008). CONCLUSIONS: Ambulatory BP monitoring is associated with disturbed sleep and reduced physical activity, characteristics that influence dipping. Ambulatory BP monitoring may itself induce nondipping and may thus mitigate the prognostic significance of the dipping phenomenon.

Agarwal R, Light RP. (Oct 2009). Physical Activity Is a Determinant of Circadian Blood Pressure Variation in Chronic Kidney Disease. Am J Nephrol, 31(1), 15-23

Background: Circadian variation in blood pressure (BP), which is commonly blunted among patients with chronic kidney disease (CKD), has been associated with increased cardiovascular risk. The causes of this blunted circadian variation remain incompletely understood. Methods: We hypothesized that physical activity is a determinant of circadian BP variation. Accordingly, we studied 101 patients with CKD (mean age 69 years, mostly men) with 24-hour ambulatory BP monitoring and simultaneous monitoring of physical activity on 2 occasions 4 weeks apart. Results: Measured by wrist actigraphy, a higher level of physical activity was associated with lower overall mean BP. A higher level of activity also altered the circadian systolic BP rhythm; this alteration was characterized by both a higher amplitude of variation (and thus greater dipping) and restoration of acrophase (time at peak BP) to a less vulnerable period for cardiovascular events. Among the most sedentary participants, both systolic and pulse pressure acrophases were seen in the early hours of the morning which is also the most vulnerable period for cardiovascular events. Conclusion: Physical activity is an independent determinant of circadian variation in BP. We speculate that among patients with CKD, a sedentary lifestyle, rather than non-dipping, mediates increased cardiovascular risk. Copyright © 2009 S. Karger AG, Basel.

Al Dhahri N, Potts JE, Chiu CC, Hamilton RM, Sanatani S. (Nov 2009). Are implantable loop recorders useful in detecting arrhythmias in children with unexplained syncope? Pacing Clin Electrophysiol, 32(11), 1422-7

INTRODUCTION: Syncope and presyncope are symptoms that occur infrequently in children, are unpredictable, and represent a diagnostic challenge to the physician. Conventional diagnostic investigations are often unable to establish a diagnosis, making it difficult to determine patient risk and direct appropriate therapy. The implantable loop recorder (ILR) is a medical device that was created for prolonged monitoring of heart rate and rhythm and has been used in a limited number of pediatric studies in which the cause of the syncope is unknown. METHODS: This is a retrospective review of the clinical, surgical, and follow-up data of patients who had ILR devices implanted after conventional testing failed to identify a cause for their symptoms. RESULTS: The diagnostic yield of the ILR device in unmasking the cause for symptoms in our patient cohort was 64%. In our study, manually activated events accounted for 71% of all documented episodes and 68% of the cases involving hemodynamically important arrhythmias or transient rhythm changes. The ILR device can be safely implanted and explanted in children without significant morbidity, in most cases. None of our patients experienced any long-term adverse events associated with placement of the device and all were alive at last follow-up. CONCLUSIONS: The use of the ILR device is a useful tool to help unmask arrhythmias as a cause of unexplained syncope in children. Patient selection for who should and should not have an ILR device implanted will continue to influence its diagnostic utility and generate controversy among stakeholders.

Alpers GW. (Dec 2009). Ambulatory assessment in panic disorder and specific phobia. Psychological Assessment, 21(4), 476-485

Anxiety disorders are among the most prevalent mental disorders. In panic disorder, panic attacks often occur at unpredictable times, making it difficult to study these episodes in the laboratory. In specific phobias, symptoms occur in very circumscribed situations and specific triggers are sometimes difficult to reproduce in the laboratory. Ambulatory assessment, or ecological momentary assessment, can further the understanding of the natural course and scope of symptoms under ecologically valid circumstances. Because bodily symptoms are integral to the diagnosis of anxiety disorders, the objective assessment of physiological responses in the patients’ natural environment is particularly important. On the one hand, research has highlighted intriguing discrepancies between the experience of symptoms and physiology during panic attacks. On the other hand, it has validated symptom reporting during therapeutic exposure to phobic situations. Therefore, ambulatory assessment can yield useful information about the psychopathology of anxiety disorders, and it can be used to monitor change during clinical interventions.

Bakker AB, Xanthopoulou, D. (Nov 2009). The crossover of daily work engagement: Test of an actor–partner interdependence model. Journal of Applied Psychology, 94(6), 1562-1571

This study of 62 dyads of employees (N = 124) examined the crossover of work engagement—a positive, fulfilling, work-related state of mind that is characterized by vigor, dedication, and absorption. We hypothesized that work engagement crosses over from an employee (the actor) to his or her colleague (the partner) on a daily basis. The frequency of daily communication was expected to moderate the crossover of daily work engagement, which in turn would relate to colleagues’ daily performance. Participants first filled in a general questionnaire and then completed a diary study over 5 consecutive workdays. The hypotheses were tested with multilevel analyses, using an actor–partner interdependence model. Results confirmed the crossover of daily work engagement, but only on days when employees within a dyad interacted more frequently than usual. Moreover, we found that actor’s work engagement (particularly vigor), when frequently communicated, had a positive indirect relationship with partner’s performance through partner’s work engagement. Finally, results showed that actor’s vigor was negatively related to partner’s performance when communication was low. However, this negative effect was counteracted when mediated by the vigor of the partner.

Banegas JR, Messerli FH, Waeber B, Rodríguez-Artalejo F, de la Sierra A, Segura J, Roca-Cusachs A, Aranda P, Ruilope LM. (Dec 2009). Discrepancies between office and ambulatory blood pressure: clinical implications. Am J Med, 122(12), 1136-41

BACKGROUND: Recent trials have documented no benefit from small reductions in blood pressure measured in the clinical office. However, ambulatory blood pressure is a better predictor of cardiovascular events than office-based blood pressure. We assessed control of ambulatory blood pressure in treated hypertensive patients at high cardiovascular risk. METHODS: We selected 4729 patients from the Spanish Ambulatory Blood Pressure Monitoring Registry. Patients were aged >/=55 years and presented with at least one of the following co-morbidities: coronary heart disease, stroke, and diabetes with end-organ damage. An average of 2 measures of blood pressure in the office was used for analyses. Also, 24-hour ambulatory blood pressure was recorded at 20-minute intervals with a SpaceLabs 90207 device. RESULTS: Patients had a mean age of 69.6 (+/-8.2) years, and 60.8% of them were male. Average time from the diagnosis of hypertension to recruitment into the Registry was 10.9 (+/-8.4) years. Mean blood pressure in the office was 152.3/82.3 mm Hg, and mean 24-hour ambulatory blood pressure was 133.3/72.4 mm Hg. About 60% of patients with an office-pressure of 130-139/85-89 mm Hg, 42.4% with office-pressure of 140-159/90-99 mm Hg, and 23.3% with office-pressure > or =160/100 mm Hg were actually normotensive, according to 24-hour ambulatory blood pressure criteria (<130/80 mm Hg). CONCLUSION: We suggest that the lack of benefit of antihypertensive therapy in some trials may partly be due to some patients having normal pressure at trial baseline. Ambulatory monitoring of blood pressure may allow for a better assessment of trial eligibility.

Barthélémy I, Barrey E, Thibaud JL, Uriarte A, Voit T, Blot S, Hogrel JY. (Nov 2009). Gait analysis using accelerometry in dystrophin-deficient dogs. Neuromuscul Disord, 19(11), 788-96

Dogs affected with Golden Retriever Muscular Dystrophy (GRMD) exhibit striking clinical similarities with patients suffering from Duchenne muscular dystrophy (DMD), particularly gait impairments. The purpose of this study was to describe the use and reliability of accelerometry in gait assessment of dogs with muscular dystrophy. Eight healthy and 11 GRMD adult dogs underwent three gait assessment sessions, using accelerometry. Three-axial recordings of accelerations were performed, and gait variables calculated. Total power, force and regularity of accelerations, stride length and speed, normalized by height at withers, stride frequency, and cranio-caudal power were significantly decreased, whereas medio-lateral power was significantly increased in GRMD dogs. Moreover, these variables were repeatable within and between sessions. Accelerometry provides reliable variables which highlight specific gait patterns of GRMD dogs, describing objectively and quantitatively their slow, short-stepped, and swaying gait. As it is easy to set-up, quick to perform and inexpensive, accelerometry represents a useful tool, to assess locomotion during pre-clinical trials.

Biddle SJ, Gorely T, Marshall SJ. (Oct 2009). Is Television Viewing a Suitable Marker of Sedentary Behavior in Young People? Ann Behav Med [Epub ahead of print]

BACKGROUND: Television (TV) viewing is a highly prevalent sedentary behavior in young people and has played a significant role in the assessment of sedentary behaviors. An important question to be addressed is to what extent TV viewing is a suitable indicator, or marker, of overall levels of sedentary behavior in children and adolescents. This has not yet been attempted in youth, but has already been attempted in Australian adults. PURPOSE: This study was conducted to test whether TV viewing in UK teenagers is a marker of sedentary behavior more broadly and to see if the results mirror those of Australian adults. METHODS: Ecological momentary assessment time-use diaries were completed by 561 boys and 923 girls (mean age 14.67 years) in which weekday and weekend out-of-school time behaviors were recorded every 15 min. RESULTS: TV viewing was negatively associated with other leisure-time sedentary behaviors for both boys and girls for weekdays and weekends. Higher levels of TV viewing were associated with less time in other key sedentary behaviors, such as computer use in boys and motorized transport in girls. CONCLUSIONS: TV viewing appears not to reflect additional time in other sedentary behaviors in British teenagers, in contrast to data from Australian women. Studies of sedentary behavior should encompass as wide a range of behaviors as possible.

Boyle J, Bidargaddi N, Sarela A, Karunanithi M. (Nov 2009). Automatic detection of respiration rate from ambulatory single-lead ECG. IEEE Trans Inf Technol Biomed, 13(6), 890-6

Ambulatory electrocardiography is increasingly being used in clinical practice to detect abnormal electrical behavior of the heart during ordinary daily activities. The utility of this monitoring can be improved by deriving respiration, which previously has been based on overnight apnea studies where patients are stationary, or the use of multilead ECG systems for stress testing. We compared six respiratory measures derived from a single-lead portable ECG monitor with simultaneously measured respiration air flow obtained from an ambulatory nasal cannula respiratory monitor. Ten controlled 1-h recordings were performed covering activities of daily living (lying, sitting, standing, walking, jogging, running, and stair climbing) and six overnight studies. The best method was an average of a 0.2-0.8 Hz bandpass filter and RR technique based on lengthening and shortening of the RR interval. Mean error rates with the reference gold standard were +/-4 breaths per minute (bpm) (all activities), +/-2 bpm (lying and sitting), and +/-1 breath per minute (overnight studies). Statistically similar results were obtained using heart rate information alone (RR technique) compared to the best technique derived from the full ECG waveform that simplifies data collection procedures. The study shows that respiration can be derived under dynamic activities from a single-lead ECG without significant differences from traditional methods.

Bruce P JM, Hancock LM, Lynch SG. (Jan 2009). Objective adherence monitoring in multiple sclerosis: initial validation and association with self-report. Mult Scler, 16(1), 112-20

Poor adherence to medication is commonplace and contributes to poor health outcomes among numerous patient populations. Studies that have examined treatment adherence in multiple sclerosis focus exclusively on retrospective self-reports and/or imprecise measures of treatment discontinuation. To help address these methodological limitations, the present longitudinal study compared adherence outcomes for patients with multiple sclerosis using retrospective self-reports, adherence diaries, and a novel electronic monitoring device. Sixty-seven patients with relapsing-remitting multiple sclerosis were followed for a period of eight weeks during which they used a medication diary and a sharps container that captured electronically the time and date of each needle disposal. The patients also reported at the outset and conclusion of the study how frequently they missed doses. All measures of adherence were highly correlated. Patients reported better adherence than was indicated by medication diaries and electronic monitoring of needle disposals. Nearly one-fifth of the sample exhibited poor adherence, missing more than 20% of their prescribed medication. The results support the validity of electronic monitoring of needle disposal as an effective means of measuring adherence to disease modifying therapies in multiple sclerosis. In contrast, studies employing only self-report may underestimate poor adherence. Larger scale studies that employ prospective objective methods are necessary to gain a better understanding of adherence patterns in multiple sclerosis.

Burke P LE, Styn MA, Glanz K, Ewing LJ, Elci OU, Conroy MB, Sereika SM, Acharya SD, Music E, Keating AL, Sevick MA. (Nov 2009). SMART trial: A randomized clinical trial of self-monitoring in behavioral weight management-design and baseline findings. Contemp Clin Trials, 30(6), 540-51

BACKGROUND: The primary form of treatment for obesity today is behavioral therapy. Self-monitoring diet and physical activity plays an important role in interventions targeting behavior and weight change. The SMART weight loss trial examined the impact of replacing the standard paper record used for self-monitoring with a personal digital assistant (PDA). This paper describes the design, methods, intervention, and baseline sample characteristics of the SMART trial. METHODS: The SMART trial used a 3-group design to determine the effects of different modes of self-monitoring on short- and long-term weight loss and on adherence to self-monitoring in a 24-month intervention. Participants were randomized to one of three conditions (1) use of a standard paper record (PR); (2) use of a PDA with dietary and physical activity software (PDA); or (3), use of a PDA with the same software plus a customized feedback program (PDA + FB). RESULTS: We screened 704 individuals and randomized 210. There were statistically but not clinically significant differences among the three cohorts in age, education, HDL cholesterol, blood glucose and systolic blood pressure. At 24 months, retention rate for the first of three cohorts was 90%. CONCLUSIONS: To the best of our knowledge, the SMART trial is the first large study to compare different methods of self-monitoring in a behavioral weight loss intervention and to compare the use of PDAs to conventional paper records. This study has the potential to reveal significant details about self-monitoring patterns and whether technology can improve adherence to this vital intervention component.

Byrd-Williams CE, Belcher BR, Spruijt-Metz D, Davis JN, Ventura EE, Kelly L, Berhane K, Azen S, Goran MI (Nov 2009). Increased Physical Activity and Reduced Adiposity in Overweight Hispanic Adolescents. Med Sci Sports Exerc [Epub ahead of print]

PURPOSE:: Objectives of this study were to examine 1) whether changes in total PA (counts/minute, cpm) and time spent in moderate to vigorous PA (MVPA) are associated with changes in adiposity and 2) whether energy intake influences the relationship between changes in PA and changes in adiposity in overweight Hispanic adolescents. METHODS:: Analysis included 38 overweight (BMI >/= 85th %ile) Hispanic adolescents with complete pre- and post-test data on relevant variables after participating in a 16-week intervention. The intervention treatment did not influence physical activity, so the sample was combined and randomization group was adjusted for in the analysis. Body composition by DEXA, 7-day physical activity by accelerometry, and dietary intake by 3-day diet records were assessed pre- and post-intervention. RESULTS:: Within individuals, the mean increase of PA (n=19) and mean decrease of PA (n=19) was approximately 105 cpm. A 100 cpm increase in total PA was associated with a decrease of 1.3 kg fat mass and 0.8% body fat after adjusting for pre-test adiposity, PA, age, sex, and treatment (p < 0.05). Controlling for energy intake modestly strengthened the relationships between total PA and fat mass and percent body fat. Changes in MVPA were not related to changes in adiposity after controlling for total PA (p>0.05). CONCLUSION:: Increasing total PA by 28% (100 cpm) was associated with a decrease of 1.4 kg of fat mass and 1% body fat over 16 weeks in overweight Hispanic adolescents independent of intervention group assignment. Increases in total physical activity, as compared to MVPA, may be sufficient to improve body composition in overweight Hispanic adolescents.

Cavanagh PR, Gopalakrishnan R, Rice AJ, Genc KO, Maender CC, Nystrom PG, Johnson MJ, Kuklis MM, Humphreys BT. (Oct 2009). An ambulatory biomechanical data collection system for use in space: design and validation. Aviat Space Environ Med, 80(10), 870-81.

INTRODUCTION: Loss in bone mineral density and muscle strength in astronauts following long-duration spaceflight have been well documented, but the altered force and movement environments in microgravity which may contribute to these changes have not been well characterized. This paper describes the instrumentation, software, and data collection procedures developed for the “Foot” experiment that was conducted on the International Space Station (ISS) to provide insight into the biomechanics of daily activity in a microgravity environment. METHODS: The instrumentation used for data collection included the Ambulatory Data Acquisition System (ADAS), ADAS electromyography (EMG) modules, the Joint Excursion System, and the Total Force-Foot Ground interface system, which were all integrated into a specially designed Lower Extremity Monitoring Suit. There were 14 total channels of data that were collected at sampling rates between 8 Hz and 1024 Hz, including 7 channels of EMG, 4 channels of joint angle data, 2 channels of in-shoe ground reaction force, and a marker channel for event recording. Data were typically collected for between 6.5 and 11.8 h of activity during 4 d on Earth and 4-7 d in flight. RESULTS: Exemplar data sets collected preflight on astronauts in 1 g to validate the instrumentation are presented. DISCUSSION: We conclude that the system provides valid and useful biomechanical information on long-term activity. The analysis of data collected on-orbit using the system described here will be presented in a series of future papers characterizing the biomechanics of astronaut activity during complete working days on the Earth and on the ISS.

Cha YD, Yoon G. (Nov 2009). Ubiquitous health monitoring system for multiple users using a ZigBee and WLAN dual-network. Telemed J E Health, 15(9), 891-7

A ubiquitous health monitoring system for multiple users was developed based on a ZigBee and wireless local area network (WLAN) dual-network. A compact biosignal monitoring unit (BMU) for measuring electrocardiogram (ECG), photoplethysmogram (PPG), and temperature was also developed. A single 8-bit microcontroller operated the BMU including most of digital filtering and wireless communication. The BMU with its case was reduced to 55 x 35 x 15 mm and 33 g. In routine use, vital signs of 6 bytes/sec (heart rate, temperature, pulse transit time) per each user were transmitted through a ZigBee module even though all the real-time data were recorded in a secure digital memory of the BMU. In an emergency or when need arises, a channel of a particular user was switched to another ZigBee module, called the emergency module, that sent all ECG and PPG waveforms in real time. Each emergency ZigBee module handled up to a few users. Data from multiple users were wirelessly received by the ZigBee receiver modules in a controller called ZigBee-WLAN gateway, where the ZigBee modules were connected to a WLAN module. This WLAN module sent all data wirelessly to a monitoring center. Operating the dual modes of ZigBee/WLAN utilized an advantage of ZigBee by handling multiple users with minimum power consumption, and overcame the ZigBee limitation of low data rate. This dual-network system for LAN is economically competitive and reliable.

Chan M, Campo E, Estève D, Fourniols JY. (Oct 2009). Smart homes - current features and future perspectives. Maturitas, 64(2), 90-7

In an ageing world, maintaining good health and independence for as long as possible is essential. Instead of hospitalization or institutionalization, the elderly and disabled can be assisted in their own environment 24h a day with numerous ‘smart’ devices. The concept of the smart home is a promising and cost-effective way of improving home care for the elderly and the disabled in a non-obtrusive way, allowing greater independence, maintaining good health and preventing social isolation. Smart homes are equipped with sensors, actuators, and/or biomedical monitors. The devices operate in a network connected to a remote centre for data collection and processing. The remote centre diagnoses the ongoing situation and initiates assistance procedures as required. The technology can be extended to wearable and in vivo implantable devices to monitor people 24h a day both inside and outside the house. This review describes a selection of projects in developed countries on smart homes examining the various technologies available. Advantages and disadvantages, as well as the impact on modern society, are discussed. Finally, future perspectives on smart homes as part of a home-based health care network are presented.

Chang TY, Lai YA, Hsieh HH, Lai JS, Liu CS. (Oct 2009). Effects of environmental noise exposure on ambulatory blood pressure in young adults. Environ Res, 109(7), 900-5

Epidemiological studies have demonstrated that environmental noise exposure is associated with hypertension in middle-aged and older populations, but the relationship in the young subpopulation and between the genders is still unclear. This panel study investigated effects of environmental noise exposure on 24-h ambulatory blood pressure in 60 adults aged 18-32 years. Individual noise exposure and personal blood pressure were measured simultaneously for 30 males and 30 females. Linear mixed-effects regression models were applied to estimate effects. Total subjects (56.6+/-16.5A-weighted decibels (dBA)) had transient elevations of 1.15 (95% CI=0.86-1.43)mmHg SBP and 1.16 (0.93-1.38)mmHg DBP at daytime, as well as 0.74 (0.21-1.26)mmHg SBP and 0.77 (0.34-1.20)mmHg DBP at nighttime, significantly associated with a 5-dBA increase in noise exposure. Such effects on SBP and DBP still persisted at the 30- and 60-min time-lagged noise exposure. Per 5-dBA increase in 24-h average noise exposure was significantly associated with sustained increments of 1.15 (0.76-1.54)mmHg SBP and 1.27 (0.96-1.58)mmHg DBP in males (57.4+/-16.0dBA), as well as the higher levels of 1.65 (1.36-1.94)mmHg SBP and 1.51 (1.27-1.75)mmHg DBP in females (55.9+/-17.0dBA). We found that environmental noise exposure may have elevated effects on adults’ blood pressure. Young females are more susceptible to noise exposure than males.

Choi L, Chen KY, Acra SA, Buchowski MS. (Dec 2009). Distributed Lag and Spline Modeling for Predicting Energy Expenditure from Accelerometry in Youth. J Appl Physiol [Epub ahead of print]

Movement-sensing using accelerometers is commonly used for the measurement of physical activity (PA) and estimating energy expenditure (EE) under free-living conditions. The major limitation of this approach is lack of accuracy and precision in estimating EE, especially in low-intensity activities. Thus, the objective of this study was to investigate benefits of a distributed lag spline (DLS) modeling approach for the prediction of total daily EE (TEE) and EE in sedentary (1.0 - 1.5 metabolic equivalents - MET), light (1.5 - 3.0 MET), and moderate/vigorous (>/= 3.0 MET) intensity activities in 10 to 17-year-old youth (n=76). We also explored feasibility of the DLS modeling approach to predict physical activity EE (PAEE) and METs. Movement was measured by Actigraph accelerometers placed on the hip, wrist, and ankle. Using a whole-room indirect calorimeter as the reference standard, prediction models (Hip, Wrist, Ankle, Hip+Wrist, Hip+Wrist+Ankle) for TEE, PAEE, and MET were developed and validated using the five-fold cross-validation method. The TEE predictions by these DLS models were not significantly different from the room calorimeter measurements (all P > 0.05). The Hip+Wrist+Ankle predicted TEE better than other models and reduced prediction errors in moderate/vigorous PA for TEE, MET and PAEE (all P < 0.001). The Hip+Wrist reduced prediction errors for the PAEE and MET at sedentary PA (P = 0.020 and 0.021) compared to the Hip. Models that included Wrist correctly classified time spent at light PA better than other models. The means and standard deviations of the prediction errors for the Hip+Wrist+Ankle and Hip were 0.4 +/- 144.0 and 1.5 +/- 164.7 kcal for the TEE, 0.0 +/- 84.2 and 1.3 +/- 104.7 kcal for the PAEE, and -1.1 +/- 97.6 and -0.1 +/- 108.6 MET min for the MET models. We conclude that the DLS approach for accelerometer data improves detailed EE prediction in youth. Key words: prediction model, accelerometry, physical activity, distributed lag model.

Connelly M, Miller T, Gerry G, Bickel J. (Dec 2009). Electronic Momentary Assessment of Weather Changes as a Trigger of Headaches in Children. Headache [Epub ahead of print]

(Headache 2009;**:**-**) Background.- Variables that are thought to precipitate migraine or tension-type headache episodes in children hitherto have only been studied using retrospective reports. As such, there is little empirical evidence to support the actual predictive association between presumed headache triggers and actual headache occurrence in children. Objective.- The present study sought to determine if fluctuations in weather, a commonly reported headache trigger in children, predict increased likelihood of headache occurrence when evaluated using rigorous prospective methodology (“electronic momentary assessment”). Methods.- Twenty-five children (21 girls, 4 boys) between the ages of 8-17 years attending a new patient neurology clinic appointment and having a diagnosis of chronic migraine, chronic tension-type, or episodic migraine headache (with or without aura) participated in the study. Children completed baseline measures on headache characteristics, presumed headache triggers, and mood and subsequently were trained in the use of electronic diaries to record information on headaches. Children then completed thrice daily diaries on handheld computers for a 2-week time period (42 assessments per child) while data on weather variables (temperature, dew point temperature, barometric pressure, humidity, precipitation, and sunlight) in the child’s geographic location were recorded each time a diary was completed. Data were analyzed using multilevel models. Results.- Of the weather variables, relative humidity and presence of precipitation were significantly predictive of new headache onset, with nearly a 3-fold increase in probability of headache occurrence during times of precipitation or elevated humidity in the child’s area, b = 0.38, t(821) = 2.10, P = .04, and b = 0.02, t(821) = 2.81, P = .01, respectively. These associations remained after accounting for fluctuations in mood, and associations were not significantly stronger in children who at baseline thought that weather was a headache trigger for them. Changes in temperature, dew point temperature, barometric pressure, and sunlight were not significantly predictive of new headache episode occurrence in this sample. Conclusions.- Results of the present study lend some support to the belief commonly held by children with recurrent headaches that weather changes may contribute to headache onset. Although electronic momentary assessment methodology was found to be feasible in this population and to have the potential to identify specific headache triggers for children, it remains to be determined how best (or even whether) to incorporate this information into treatment recommendations.

Cranford JA, Tennen H, Zucker RA. (Dec 2009). Feasibility of Using Interactive Voice Response to Monitor Daily Drinking, Moods, and Relationship Processes on a Daily Basis in Alcoholic Couples. Alcohol Clin Exp Res [Epub ahead of print]

Background: Daily process research on alcohol involvement has used paper-and-pencil and electronic data collection methods, but no studies have yet tested the feasibility of using Interactive Voice Response (IVR) technology to monitor drinking, affective, and social interactional processes among alcoholic (ALC) couples. This study tested the feasibility of using IVR with n = 54 ALC couples. Methods: Participants were n = 54 couples (probands who met criteria for a past 1-year alcohol use disorder and their partners) recruited from a substance abuse treatment center and the local community. Probands and their partners reported on their daily drinking, marital interactions, and moods once a day for 14 consecutive days using an IVR system. Probands and partners were on average 43.4 and 43.0 years old, respectively. Results: Participants completed a total of 1,418 out of a possible 1,512 diary days for an overall compliance rate of 93.8%. ALC probands completed an average of 13.3 (1.0) diary reports, and partners completed an average of 13.2 (1.0) diary reports. On average, daily IVR calls lasted 7.8 (3.0) minutes for ALC probands and 7.6 (3.0) minutes for partners. Compliance was significantly lower on weekend days (Fridays and Saturdays) compared to other weekdays for probands and spouses. Although today’s intoxication predicted tomorrow’s noncompliance for probands but not spouses, the strongest predictor of proband’s compliance was their spouse’s compliance. Daily anxiety and marital conflict were associated with daily IVR nonresponse, which triggered automated reminder calls. Conclusions: Findings supported that IVR is a useful method for collecting daily drinking, mood, and relationship process data from alcoholic couples. Probands’ compliance is strongly associated with their partners’ compliance, and automated IVR calls may facilitate compliance on high anxiety, high conflict days.

Davison KK, Deane GD. (Aug 2009). The consequence of encouraging girls to be active for weight loss. Soc Sci Med, [Epub ahead of print]

The purpose of the study, conducted in Pennsylvania, USA, was to assess the prospective effect of parental encouragement of physical activity (PA) for weight loss on adolescent girls’ concern about weight, Body Mass Index (BMI) and objectively-measured PA. Non-Hispanic White girls (N = 177) and their parents were assessed when girls were 9, 11, 13 and 15 years old. At each age, girls’ concern about their weight, pubertal development, BMI, and dietary intake were measured along with mothers’ and fathers’ encouragement of PA for weight loss, modeling of PA, and logistic support for PA. At ages 13 and 15 years, girls’ PA was assessed using accelerometry. At age 11, girls’ PA was measured using a combination of self-report measures and a standardized assessment of cardiovascular fitness. Parents of obese girls reported the highest encouragement of PA for weight loss; however, girls from all weight categories were exposed to encouragement of PA for weight loss and showed similar age-related increases in parental encouragement. Encouragement of PA for weight loss was prospectively associated with higher concern about weight and higher BMI, independent of pre-existing levels of these constructs and covariates. Encouragement of PA for weight loss was not associated with girls’ objectively-measured PA. Parental encouragement of PA for weight loss was therefore not an effective strategy in this sample. Findings are consistent with research on parental child feeding practices, where parental control has been linked with unintended negative dietary and psychosocial outcomes among children.

Davison RR, Van Someren KA, Jones AM. (Oct 2009). Physiological monitoring of the Olympic athlete. J Sports Sci, [Epub ahead of print]

As the winning margin in Olympic competition is so small, there is a continuous quest for improvements in the preparation of athletes at this standard. Therefore, even the smallest physiological improvements that result from modifications in training strategy, preparation regime or ergogenic aids are potentially useful. Unfortunately, there is a lack of research data on elite competitors, which limits our interpretation of current literature to the elite sporting environment. This places extra responsibility on the physiologist to carefully consider the most appropriate physiological variables to monitor, the best protocols to assess those variables, and the accurate interpretation of the test results. In this paper, we address the key issues of ecological validity, measurement error, and interpretation for the most commonly monitored physiological variables. Where appropriate, we also indicate areas that would benefit from further research.

Dencker M, Thorsson O, Karlsson MK, Lindén C, Wollmer P, Andersen LB. (Oct 2009). Objectively measured daily physical activity related to cardiac size in young children. Scand J Med Sci Sports, 19(5), 664-8

Training studies in children have suggested that endurance training can give enlargement of cardiac dimensions. This relationship has not been studied on a population-based level in young children with objective methods. A cross-sectional study was made of 248 children (140 boys and 108 girls), aged 8-11 years, from a population-based cohort. Left ventricular end-diastolic diameter (LVDD) and left atrial end-systolic diameter (LA) were measured with echocardiography and indexed for body surface area (BSA). Physical activity was assessed by accelerometry, and the duration of vigorous physical activity per day (VPA) was calculated. Acceptable accelerometer and echocardiography measurements were obtained in 228 children (boys=127, girls=101). Univariate correlations between VPA and LVDD were indexed for BSA in boys (r=0.27, P<0.05) and in girls (r=0.10, NS). Multiple regression analysis showed that independent factors for LVDD, indexed for BSA for boys, were age and VPA. LA indexed for BSA was not related to physical activity variables in either gender. No clear relationship exists between cardiac size and daily physical activity in children aged 8-11 years. This suggests that significant cardiac remodelling due to volume exposure secondary to a high amount of physical activity begins later in life

Ebner-Priemer Ebner-Priemer UW, Trull, TJ. (Dec 2009). Ecological momentary assessment of mood disorders and mood dysregulation. Psychological Assessment, 21(4), 463-475

In this review, we discuss ecological momentary assessment (EMA) studies on mood disorders and mood dysregulation, illustrating 6 major benefits of the EMA approach to clinical assessment: (a) Real-time assessments increase accuracy and minimize retrospective bias; (b) repeated assessments can reveal dynamic processes; (c) multimodal assessments can integrate psychological, physiological, and behavioral data; (d) setting- or context-specific relationships of symptoms or behaviors can be identified; (e) interactive feedback can be provided in real time; and (f) assessments in real-life situations enhance generalizability. In the context of mood disorders and mood dysregulation, we demonstrate that EMA can address specific research questions better than laboratory or questionnaire studies. However, before clinicians and researchers can fully realize these benefits, sets of standardized e-diary questionnaires and time sampling protocols must be developed that are reliable, valid, and sensitive to change.

Edwards AG, Hill JO, Byrnes WC, Browning RC. (Nov 2009). Accuracy of Optimized Branched Algorithms to Assess Activity-Specific PAEE. Med Sci Sports Exerc [Epub ahead of print]

PURPOSE: To assess the activity-specific accuracy achievable by branched algorithm (BA) analysis of simulated daily-living physical activity energy expenditure (PAEE) within a sedentary population. METHODS:: Sedentary men (n=8) and women (n=8) first performed a treadmill calibration protocol, during which heart rate (HR), accelerometry (ACC), and PAEE were measured in 1-minute epochs. From these data, HR-PAEE, and ACC-PAEE regressions were constructed and used in each of six analytic models to predict PAEE from ACC and HR data collected during a subsequent simulated daily-living protocol. Criterion PAEE was measured during both protocols via indirect calorimetry. The accuracy achieved by each model was assessed by the root mean square of the difference between model-predicted daily-living PAEE and the criterion daily-living PAEE (expressed here as % of mean daily-living PAEE). RESULTS:: Across the range of activities an unconstrained post hoc optimized branched algorithm best predicted criterion PAEE. Estimates using individual calibration were generally more accurate than those using group calibration (14 vs. 16 % error, respectively). These analyses also performed well within each of the six daily-living activities, but systematic errors appeared for several of those activities, which may be explained by an inability of the algorithm to simultaneously accommodate a heterogeneous range of activities. Analyses of between mean square error by subject and activity suggest that optimization involving minimization of RMS for total daily-living PAEE is associated with decreased error between subjects but increased error between activities. CONCLUSION:: The performance of post hoc optimized branched algorithms may be limited by heterogeneity in the daily-living activities being performed.

Engel SG, Kahler KA, Lystad CM, Crosby RD, Simonich HK, Wonderlich SA, Peterson CB, Mitchell JE. (Oct 2009). Eating behavior in obese BED, obese non-BED, and non-obese control participants: a naturalistic study. Behav Res Ther, 47(10), 897-900

Laboratory studies have shown considerable differences between the eating behavior, particularly binge eating behavior, of participants with and without binge eating disorder (BED). However, these findings were not replicated in two field experiments employing ecological momentary assessment (EMA) in which obese BED and obese non-BED participants reported comparable binge eating behavior. In the current study, we examined differences in binge eating with an innovative assessment scheme employing both EMA and a standardized computer-based dietary recall program to avoid some of the limitations of past laboratory and field research. Obese BED, obese non-BED, and non-obese control participants reported significant differences in eating patterns, loss of control, overeating, and binge eating behavior. Of particular importance was the finding that BED participants engaged in more overeating and more binge eating episodes than non-BED participants. These findings suggest that the use of EMA in combination with dietary recall may be a relatively objective and useful approach to assessing binge eating behavior. The findings further suggest that individuals with BED are observably different from those without the disorder, which may have implications for eating disorder diagnoses in DSM-V.

Epstein DH, Marrone GF, Heishman SJ, Schmittner J, Preston KL. (Nov 2009). Tobacco, cocaine, and heroin: Craving and use during daily life. Addictive Behaviors, Nov 12, 2009

BACKGROUND: Relationships among tobacco smoking, tobacco craving, and other drug use and craving may have treatment implications in polydrug-dependent individuals. METHODS: We conducted the first ecological momentary assessment (EMA) study to investigate how smoking is related to other drug use and craving during daily life. For up to 20weeks, 106 methadone-maintained outpatients carried PalmPilots (PDAs). They reported their craving, mood, behaviors, environment, and cigarette-smoking status in 2 to 5random-prompt entries/day and initiated PDA entries when they used cocaine or heroin or had a discrete episode of craving for cocaine or heroin. RESULTS: Smoking frequency increased linearly with random-prompt ratings of tobacco craving, cocaine craving, and craving for both cocaine and heroin. Smoking frequency was greater during discrete episodes of cocaine use and craving than during random-prompt reports of low craving for cocaine. This pattern was also significant for dual cocaine and heroin use and craving. Smoking and tobacco craving were each considerably reduced during periods of urine-verified abstinence from cocaine, and there was a (nonsignificant) tendency for morning smoking to be especially reduced during those periods. CONCLUSIONS: This EMA study confirms that smoking and tobacco craving are strongly associated with the use of and craving for cocaine and heroin. Together with prior findings, our data suggest that tobacco and cocaine may each increase craving for (and likelihood of continued use of) themselves and each other. Treatment for tobacco dependence should probably be offered concurrently with (rather than only after) initiation of treatment for other substance-use disorders.

Faber GS, Kingma I, Bruijn SM, van Dieën JH. (Oct 2009). Optimal inertial sensor location for ambulatory measurement of trunk inclination. J Biomech, 42(14), 2406-9

Trunk inclination (TI) is used often to quantify back loading in ergonomic workplace evaluation. The aim of the present study was to determine whether TI can be obtained using a single inertial sensor (IS) on the back, and to determine the optimal IS location on the back for the estimation of TI. Gold standard TI, the angle between the vertical and the line connecting the L5/S1 joint and the trunk centre of mass, was measured using an optoelectronic system. Ten subjects performed experimental trials, each consisting of a symmetric and an asymmetric lifting task, and of a left-right lateral flexion movement. Trials were repeated and, in between trials, the IS was shifted in small steps from a location on the thorax towards a location on the sacrum. Optimal IS location was defined as the IS location with minimum root-mean-square (RMS) error between the gold standard TI and the IS TI. Averaged over subjects, the optimal IS location for symmetric and asymmetric lifting was at about 25% of the distance from the midpoint between the posterior superior iliac spines (MPSIS) to the C7 spinous process. The RMS error at this location, averaged over subjects, was 4.6+/-2.9 degrees. For the left-right lateral flexion task, the optimal IS location was at about 30% of the MPSIS to C7 distance. Because in most activities of daily living, pure lateral flexion does not occur often, it is recommended place the IS at 25% of the distance from the MPSIS to C7.

Favre J, Aissaoui R, Jolles BM, de Guise JA, Aminian K. (Oct 2009). Functional calibration procedure for 3D knee joint angle description using inertial sensors. J Biomech, 42(14), 2330-5

Measurement of three-dimensional (3D) knee joint angle outside a laboratory is of benefit in clinical examination and therapeutic treatment comparison. Although several motion capture devices exist, there is a need for an ambulatory system that could be used in routine practice. Up-to-date, inertial measurement units (IMUs) have proven to be suitable for unconstrained measurement of knee joint differential orientation. Nevertheless, this differential orientation should be converted into three reliable and clinically interpretable angles. Thus, the aim of this study was to propose a new calibration procedure adapted for the joint coordinate system (JCS), which required only IMUs data. The repeatability of the calibration procedure, as well as the errors in the measurement of 3D knee angle during gait in comparison to a reference system were assessed on eight healthy subjects. The new procedure relying on active and passive movements reported a high repeatability of the mean values (offset<1 degrees) and angular patterns (SD<0.3 degrees and CMC>0.9). In comparison to the reference system, this functional procedure showed high precision (SD<2 degrees and CC>0.75) and moderate accuracy (between 4.0 degrees and 8.1 degrees) for the three knee angle. The combination of the inertial-based system with the functional calibration procedure proposed here resulted in a promising tool for the measurement of 3D knee joint angle. Moreover, this method could be adapted to measure other complex joint, such as ankle or elbow.

Finazzi ME, Mesquita ME, Lopes JR, Fu LI, Oliveira MG, Del Porto JA. (Nov 2009). Motor activity and depression severity in adolescent outpatients. Neuropsychobiology, 61(1), 33-40

OBJECTIVES: The present study investigated the association between motor activity and severity of depression in 6 depressed adolescent outpatients. METHOD: Motor activity was assessed by actigraphy and the severity of depression was assessed weekly using the CDRS-R. The levels of motor activity were analyzed by considering activity parameters. RESULTS: Among the parameters of motor activity studied, the mean total activity, the mean 24-hour activity levels, the mean waking activity, and the mean activity level between 12:00 and 18:00 h were inversely correlated with severity of depression. The means of the 10 most active hours tended toward a negative correlation with the depressive severity score. CONCLUSION: The results seem to suggest an association between motor activity level and severity of depression in adolescents. Nevertheless, in order to reach a more conclusive understanding, it would be necessary to replicate this study using a larger number of individuals as well as a longer observation period.

Friedman O, Shukla Y, Logan AG. (Nov 2009). Relationship between self-reported sleep duration and changes in circadian blood pressure. Am J Hypertens, 22(11), 1205-11

BACKGROUND: Abnormalities in sleep duration and circadian blood pressure (BP) rhythm are both independently associated with increased risk of death and cardiovascular disease. The relationship, however, between these two entities remains unclear. This study was undertaken to determine whether abnormal sleep duration is associated with nondipping status and elevated morning surge. METHODS: In a cross-sectional study, we assessed the relationship between self-reported sleep duration and circadian BP profiles from 24-h ambulatory BP monitoring (ABPM) in 108 normotensive and 417 hypertensive subjects, independent of relevant sociodemographic, anthropometric, and medical factors. RESULTS: On average, subjects reported sleeping 6.5 +/- 1.7 h with 18.5% sleeping < or =5 h and 7.6%, > or =9 h. There were 199 (37.9%) nondippers in our cohort and the mean morning surge was 18.7 +/- 1.7 mm Hg. The adjusted odds ratio for nondipping (<10% nocturnal systolic BP fall) associated with a 1-h decrement in sleep duration was 1.12 (P = 0.04) and with age per 5-year increment, 1.15 (P = 0.0003). The adjusted odds ratio for an elevated morning surge (> or =18.0 mm Hg) associated with a 1-h increment in sleep duration was 1.13 (P = 0.02). CONCLUSIONS: Our study indicates that a sleep deficit is associated with nondipping and a decreased morning surge, whereas a sleep surfeit is associated with less nondipping and an increased morning surge. These findings provide a possible link for the heightened risk of cardiovascular disease associated with disturbances in circadian BP rhythm and the extremes of sleep quantity.

Gehricke J-G, Hong N, Whalen CK, Steinhoff K, Wigal TL. (Aug 2009). Effects of transdermal nicotine on symptoms, moods, and cardiovascular activity in the everyday lives of smokers and nonsmokers with attention-deficit/hyperactivity disorder. Psychology of Addictive Behaviors, 23(4), 644-655

Abstract: The aim of the study was to test the self-medication hypothesis by examining the effects of nicotine in the everyday lives of smokers and nonsmokers with attention-deficit/hyperactivity disorder (ADHD). Fifty-two adults with ADHD (25 abstinent smokers and 27 nonsmokers) participated in a double-blind placebo controlled study with one nicotine patch condition and one placebo patch condition in counterbalanced order. Each condition continued for two consecutive days in which patches were administered each morning. The effects of nicotine on ADHD symptoms, moods, and side effects were assessed with electronic diaries. Cardiovascular activity was recorded with ambulatory blood pressure monitors and physical activity was monitored with actigraphs. Nicotine reduced reports of ADHD symptoms by 8% and negative moods by 9%, independent of smoking status. In addition, nicotine increased cardiovascular activity during the first 3 to 6 hours after nicotine patch administration. The results support the self-medication hypothesis for nicotine in adults with ADHD and suggest that smoking cessation and prevention efforts for individuals with ADHD will need to address both the symptom reducing and mood enhancing effects of nicotine.

Godfrey A, Conway R, Leonard M, Meagher D, Olaighin GM. (Nov 2009). Motion analysis in delirium: A discrete approach in determining physical activity for the purpose of delirium motoric subtyping. Med Eng Phys [Epub ahead of print]

The purpose of this study was to determine the use and feasibility of accelerometry-based monitoring and to examine a discrete multi-resolution signal analysis technique to determine motoric subtypes in patients with DSM-IV delirium. Forty consecutive patients receiving palliative care (23 male, 17 female, mean age+/-standard deviation 68.4+/-11.9 years) were assessed using 24-h accelerometer-based monitoring. The total amount of time spent per activity of sitting/lying, standing and stepping were calculated. This was achieved through the multilevel decomposition and reconstruction of the accelerometer signals by means of the discrete wavelet transform. Both the reconstructed approximations and details of the discrete transform were used for motoric subtyping. This was compared to a validated activity monitor for validation purposes. Demographic and clinical data per patient were also collected. Of the 40 patients selected for accelerometry, complete 24-h readings were available for 34 patients and analyses were confined to this group. Of the 34 patients included, 25 met criteria for DSM-IV delirium while 9 were non-delirious comparison subjects with equivalent medical diagnoses receiving treatment in the same setting. It was concluded that accelerometry-based measurement of a delirious cohort within a palliative setting is both a reliable and feasible method of continuous monitoring. Of the activities performed by the patients, periods of standing proved to be the most discriminatory in determining between each subtype.

Goñi A, Burgos A, Dranca L, Rodríguez J, Illarramendi A, Bermúdez J. (Nov 2009). Architecture, cost-model and customization of real-time monitoring systems based on mobile biological sensor data-streams. Comput Methods Programs Biomed, 96(2), 141-57

Innovation in the fields of wireless data communications, mobile devices and biosensor technology enables the development of new types of monitoring systems that provide people with assistance anywhere and at any time. In this paper we present an architecture useful to build those kind of systems that monitor data streams generated by biological sensors attached to mobile users. We pay special attention to three aspects related to the system efficiency: selection of the optimal granularity, that is, the selection of the size of the input data stream package that has to be acquired in order to start a new processing cycle; the possible use of compression techniques to store and send the acquired input data stream and; finally, the performance of a local analysis versus a remote one. Moreover, we introduce two particular real systems to illustrate the suitability and applicability of our proposal: an anywhere and at any time monitoring system of heart arrhythmias and an apnea monitoring system.

Griffith SD, Shiffman S, Heitjan DF. (Nov 2009). A method comparison study of timeline followback and ecological momentary assessment of daily cigarette consumption. Nicotine Tob Res, 11(11), 1368-73

INTRODUCTION: Uncertainty exists about how best to measure daily cigarette consumption. Two common measures are timeline followback (TLFB), which involves structured, prompted recall, and ecological momentary assessment (EMA), which involves recording consumption, as it occurs, on a handheld electronic device. METHODS: We evaluated the agreement between TLFB and EMA measures collected for 14 days prior to the target quit date from 236 smokers in a smoking cessation program. We performed a Bland-Altman analysis to assess agreement of TLFB and EMA using a regression-based model that allows for a nonuniform difference between methods and limits of agreement that can vary with the number of cigarettes smoked. RESULTS: For pairs of measurements taken on the same smoker, TLFB counts were on average 3.2 cigarettes higher than EMA counts; this difference increased for larger numbers of cigarettes. Using a model that allows for variable limits of agreement, the width of the 95% interval ranged from 8.7 to 61.8 cigarettes, with an average of 26.4 cigarettes. Variation between the methods increased substantially for larger cigarette counts, leading to wider limits and poorer agreement for heavy smokers. DISCUSSION: Throughout the measurement range, the estimated limits of agreement were far wider than the limits of clinical significance, defined a priori to be 20% of the number of cigarettes smoked. We conclude that TLFB and EMA cannot be considered equivalent for the assessment of daily cigarette consumption, especially for heavy smokers.

Hanlon M, Anderson R. (Nov 2009). Real-time gait event detection using wearable sensors. Gait Posture, 30(4), 523-7

Real-time gait event detection is a requirement for functional electrical stimulation and gait biofeedback. This gait event detection should ideally be achieved using an ambulatory system of durable, lightweight, low-cost sensors. Previous research has reported issues with durability in footswitch systems. Therefore, this study describes the development and assessment of novel detection algorithms using footswitch and accelerometer sensors on 12 healthy individuals. Subjects were equipped with one force sensitive resistor on the heel, one accelerometer at the foot, and one accelerometer at the knee. Subjects performed 10, 8-m walking trials in each of three conditions: normal, slow, and altered (reduced knee ROM) walking. Data from a subset of four subjects were used to develop prediction algorithms for initial contact (IC). Subsequently, these algorithms were tested on the remaining eight subjects against standard forceplate IC data (threshold of 5 N on a rising edge). The footswitch force threshold algorithm was most accurate for IC detection (mean absolute error of 2.4+/-2.1 ms) and was significantly more accurate (p<0.001) than the optimal accelerometer algorithm (mean absolute error of 9.5+/-9.0 ms). The optimal accelerometer algorithm used data from both accelerometers, with IC determined from the second derivative of foot fore-aft acceleration. The error results for footswitch and accelerometer algorithms are lower (approximately 60%) than in previous research on ambulatory real-time gait event detection systems. Currently, footswitch systems must be recommended over accelerometer systems for accurate detection of IC, however, further research into accelerometer algorithms is merited due to its advantages as a durable, low-cost sensor.

Hautala AJ, Karjalainen J, Kiviniemi AM, Kinnunen H, Makikallio TH, Huikuri HV, Tulppo MP. (Dec 2009 Physical Activity and Heart Rate Variability Measured Simultaneously during Waking Hours. Am J Physiol Heart Circ Physiol [Epub ahead of print]

Heart rate variability (HRV) during ambulatory recordings may be affected by individual differences in daily physical activity (PA). The influence of various levels of PA on different measures of HRV is not exactly known, however. We examined the association between simultaneously measured HRV and objective PA data obtained with an accelerometer during waking hours among 45 healthy adults. Bouts of PA were identified from minute-by-minute accelerometer data as metabolic equivalent (METs) values and calculated as mean METs for 30 min. HRV was analyzed concurrently. Within-individual correlation analyses and sign tests were performed to study the relationships between various HRV indices and PA. The mean PA time was 15:44 +/- 1:01 hours and the mean METs were 1.91 +/- 0.14. Heart rate (HR) and sample entropy, but not the other measures of HRV, had a significant relationship with the PA shown by both the correlation analyses (r = 0.64, P = 0.021 and r = -0.55, P = 0.022, respectively) and the sign tests (P < 0.0001 for both). Beat to beat R-R interval fluctuation expressed as SD1 demonstrated also a significant relation to PA according to the sign test (P = 0.037) and a trend of association according to the correlation analysis (r = -0.40, P = 0.129). Complexity measure of HRV, in addition to average HR and short-term index of HRV (SD1), is significantly influenced by the level of PA during ambulatory conditions. Long-term HRV indices remain relatively stable at various activity levels, making them most robust indices for assessment of cardiac autonomic function during free-running ambulatory conditions. Key words: physical activity, accelerometer, cardiovascular autonomic regulation, heart rate variability.

Hermida RC, Ayala DE, Mojón A, Fernández JR. (Aug 2009). Effects of Time of Antihypertensive Treatment on Ambulatory Blood Pressure and Clinical Characteristics of Subjects With Resistant Hypertension. Am J Hypertens [Epub ahead of print]

BackgroundSubjects with resistant hypertension present high prevalence of a nondipper blood pressure (BP) pattern, associated with increased risk of cardiovascular events. Nondipping is partly related to the absence of 24-h therapeutic coverage in hypertensives treated with single morning doses.MethodsWe studied the impact of treatment time on ambulatory BP and clinical characteristics of 1,794 subjects with resistant hypertension, categorized according to the time of treatment (either ingesting all antihypertensive medications upon awakening, or >/=1 drug at bedtime). BP was measured for 48 consecutive hours, and physical activity was simultaneously monitored every minute by wrist actigraphy.ResultsThe percentage of controlled subjects was higher among those taking medication at bedtime (P < 0.001). Among the 1,306 participants with true resistant hypertension, those ingesting >/=1 drug at bedtime showed significantly lower 24-h mean of systolic BP (SBP)/diastolic BP (DBP) (by 4.1/1.5 mm Hg, respectively; P < 0.015). The difference between groups was more prominent in asleep BP (9.7/4.4 mm Hg, P < 0.001). The awake/asleep BP ratio was significantly higher by 5.8% (P < 0.001) and the prevalence of nondipping lower from 83 to 40% (P < 0.001) in subjects receiving bedtime treatment. This latter group also showed significant lower mean values of glucose, total cholesterol, low-density lipoprotein-cholesterol, fibrinogen, and urinary albumin excretion.ConclusionsIn resistant hypertension, pharmacological therapy should take into account when to treat with respect to the rest-activity cycle of each subject. Bedtime treatment was associated with greater clinic and ambulatory BP control, lower prevalence of a high-risk nondipper pattern, and lower values of relevant clinical markers of cardiovascular risk.

Holtz B, Whitten P. (Nov 2009). Managing asthma with mobile phones: a feasibility study. Telemed J E Health, 15(9), 907-9.

Asthma is a chronic disease and a growing health problem worldwide. The objective of this pilot study was to test the feasibility and utilization of tracking asthma symptoms through an innovative mobile phone application. The subjects for this research project consisted of 4 individuals who are currently receiving treatment for asthma from a primary care physician in Ingham County, Michigan. Participants took their peak flow reading each day and used the short message service (SMS) function on their phone and sent it to a Web server. If they did not send it by 11 AM, they received a reminder via an automated SMS to their phone. The resulting data suggest that this method of management is feasible. The data also demonstrate participants’ satisfaction in monitoring their asthma in this manner. Using mobile phones for asthma management could improve compliance with asthma action plans and reduce adverse asthma events. Future research could further demonstrate that mobile phones are a new and effective method for providing healthcare.

Hopenfeld B, John MS, Fischell DR, Medeiros P, Guimarães HP, Piegas LS. (Nov 2009). The Guardian: an implantable system for chronic ambulatory monitoring of acute myocardial infarction. J Electrocardiol, 42(6), 481-6.

The AngelMed Guardian is an implantable medical device that records cardiac data and detects ischemic events using a standard pacemaker intracardiac lead positioned in the right ventricular apex. The Guardian has been implanted in 55 people in the United States and Brazil and is currently undergoing a Food and Drug Administration phase 2 pivotal trial in the United States. The Guardian detects acute ischemic events by analyzing ST-segment shifts. The ST-segment shifts are calculated as the difference between the ST deviation of a current 10-second electrogram window and a baseline ST deviation value. If the ST-segment shift is greater than a heart rate-dependent programmable threshold, then the device generates an emergency alert signal. Results thus far have demonstrated that (i) the intracardiac electrogram is relatively noise-free and (ii) the ST-shift technique used by the Guardian is effective for detecting acute ischemic events.

Houtveen JH, Hamaker EL, Van Doornen LJ. (Dec 2009). Using multilevel path analysis in analyzing 24-h ambulatory physiological recordings applied to medically unexplained symptoms. Psychophysiology [Epub ahead of print]

A non-clinical group high on heterogeneous medically unexplained symptoms (MUS; n=97) was compared with healthy controls (n=66) on the within-subject relationships between physiological measures using multilevel path analysis. Momentary experienced somatic complaints, mood (tension and depression), cardiac autonomic activity (inter-beat intervals, pre-ejection period (PEP), and respiratory sinus arrhythmia (RSA)) and respiration (rate and partial pressure of CO(2) at the end of a normal expiration) were monitored for 24 h using electronic diary and ambulatory devices. Relationships between measures were controlled for diurnal variation and individual means. Only subtle group differences were found in the diurnal rhythm and in the within-subject relationships between physiological measures. For participants high on MUS, within-subject changes in bodily symptoms were related to changes in mood, but only marginally to the physiological measures. Results of the current path analysis confirm the subordinate role of cardiac autonomic and respiratory parameters in MUS.

Hsieh JC, Yu KC, Yang CC.(Nov 2009). The realization of ubiquitous 12-lead ECG diagnosis in emergency telemedicine. Telemed J E Health, 15(9), 898-906

This study presents an e-technology to realize a mobile 12-lead electrocardiography (ECG) information system capable of providing clinicians with ubiquitous 12-lead ECG diagnoses. Until now, there has been limited information on mobile systems that can exchange information with clinically used 12-lead ECG for emergency telemedicine. The development of mobilized 12-lead ECG diagnoses in clinical practice is impeded by the heterogeneous 12-lead ECG file formats and compressed ECG waveform data. In this study, clinically used Standard Communications Protocol ECG and Extensible Markup Language ECG interpreters were developed to extract compressed 12-lead ECG waveform data. A 12-lead ECG database server connecting with a hospital information system was then built to collect 12-lead ECG files and related clinical data. Additionally, a mobile 12-lead ECG database was implemented on mobile phones for remote 12-lead ECG diagnoses. Clinical evaluations confirmed the usefulness of this mobile 12-lead ECG information system, which significantly improves the diagnostic accuracy and the performance of medical treatments in cardio-emergency telemedicine. In summary, this system facilitated ubiquitous 12-lead ECG diagnoses and enhanced the efficiency and service quality of emergency telemedicine.

Huijnen IP, Verbunt JA, Roelofs J, Goossens M, Peters M. (Nov 2009). The disabling role of fluctuations in physical activity in patients with chronic low back pain. European Journal of Pain, 13(10), 1076-1079

Patients with chronic low back pain (CLBP) often report a disabling decrease in their activity level due to pain. The nature of the association between disability, activity, and pain over time is however, unclear. An intriguing issue here is whether a high level of pain-related disability is associated with a low activity level or are changes in the level of activity over time pain provoking and thus more disabling? The objectives of this study were to investigate associations between disability, pain intensity, pain-related fear, and characteristics of physical activity in patients with CLBP. A total of 42 patients with CLBP were recruited from the Pain Clinic of the Maastricht University Hospital. Each pain patient carried an electronic diary for one week, in which questions about current pain intensity, and the level of physical activity were completed at 8 moments a day. Disability was scored by the Quebec Back Pain Disability Scale (QBPDS), Fear of movement by the Tampa Scale for Kinesiophobia (TSK). To explain the level of disability regression analyses were performed with disability as dependent variable and pain intensity, pain-related fear, and consecutively the level of physical activity in daily life and fluctuations in physical activity as independent variables. Results, based on 34 patients, showed that activity fluctuations (β =0.373, p <0.05) rather than the mean activity level over time (β =−0.052, ns) contributed significantly in explaining disability. The results are discussed in the light of current theories, previous research, and clinical implications.

Hynynen E, Konttinen N, Rusko H. (Nov 2009). Heart rate variability and stress hormones in novice and experienced parachutists anticipating a jump. Aviat Space Environ Med, 80(11), 976-80

INTRODUCTION: Chronic work stress and overtraining are known to influence heart rate (HR) and heart rate variability (HRV) at rest and decreased nocturnal HRV is associated with cardiovascular health and disease. The purpose of this study was to examine whether anticipation of an acute highly stressful event influences HR and HRV during the night and morning. METHODS: Nocturnal HR and HRV and urinary stress hormones (cortisol, adrenaline, noradrenaline) as well as HR and HRV responses to an orthostatic test on the morning of a parachute jump day or control day were analyzed from 14 novice and 7 experienced parachute jumpers. RESULTS: There were no differences in any HRV indices during the night or the orthostatic test between the jump and control situations. The novices had higher HR than experienced jumpers in the orthostatic test in the morning and also during the jump, but no differences were found between the groups in nocturnal HR and HRV indices or HRV indices during the orthostatic test. There were no differences in nocturnal stress hormone secretions except slightly elevated adrenaline secretion during the jump night compared to the control night (P = 0.014). CONCLUSIONS: The parachute jump did not substantially influence HR, HRV, or stress hormones during the night or the orthostatic test in the morning preceding the jump. The results suggest that the parachute jump as an acute highly stressful event had no anticipatory effect on autonomic modulation of the heart even though both the novices and experienced jumpers had markedly accentuated sympathetic activation during the parachuting.

Jacobson JS, Lieblein A, Fierman AH, Fishkin ER, Hutchinson VE, Rodriguez L, Serebrisky D, Chau M, Saperstein A. (Aug 2009). Randomized trial of an electronic asthma monitoring system among New York City children. Am J Manag Care, 15(11), 809-14

OBJECTIVES: To test the efficacy of an electronic asthma monitoring system (AMS) to reduce pediatric emergency department (ED) visits and hospitalizations for asthma. STUDY DESIGN: Randomized clinical trial. METHODS: Families of pediatric patients with asthma aged 8 to 17 years were recruited at 6 medical centers. Children were randomly assigned to the American Medical Alert Corporation pediatric AMS or a paper diary. The numbers of and costs associated with ED visits and hospitalizations for the 2 groups in the year following randomization were compared using t tests of statistical significance. RESULTS: Of 59 children recruited to the trial, 29 were randomized to the AMS and 30 to the diary. The 2 groups were similar in demographic and clinical characteristics. During their study year, 24 AMS group members logged on a mean (SD) of 211.0 (117.3) days; 13 diary group members provided data on a mean (SD) of 136.6 (128.0) days. During the 32 months that the study was in progress, the case managers logged on a mean (SD) of 171.0 (97.2) days. Overall, 35 children had at least 1 ED visit, but only 7 children were hospitalized. The 2 groups had no statistically significant differences in the numbers of or charges associated with ED visits or hospitalizations. CONCLUSION: Electronic devices are being developed to make chronic disease management easier for patients and their families, but they should not be adopted without careful study, including randomized trials, to ascertain their use, costs, and benefits.

Japuntich SJ, Piper ME, Schlam TR, Bolt DM, Baker TB (Dec 2009). Do smokers know what we’re talking about? The construct validity of nicotine dependence questionnaire measures. Psychological Assessment, 21(4), 595-607

Few studies have examined whether nicotine dependence self-report questionnaires can predict specific behaviors and symptoms at specific points in time. The present study used data from a randomized clinical trial (N = 608; M. E. Piper et al., 2007) to assess the construct validity of scales and items from 3 nicotine dependence measures: the Fagerström Test for Nicotine Dependence (T. F. Heatherton, L. T. Kozlowski, R. C. Frecker & K.-O. Fagerström, 1991), the Nicotine Dependence Syndrome Scale (S. Shiffman, A. J. Waters, & M. Hickcox, 2004), and the Wisconsin Inventory of Smoking Dependence Motives (M. E. Piper et al., 2004). Scales from these measures were used to predict participants’ reports on real-time measures of withdrawal symptoms and smoking behavior and retrospective self-report questionnaires to assess convergent and discriminative validity. The nicotine dependence measures’ scales and items generally predicted the real-time measures of similar constructs, but the percent of variance accounted for was low. The nicotine dependence measures did, however, show evidence of discriminative validity. Thus, this study provides modest support for the construct validity of these nicotine dependence scales.

Jentzsch NS, Camargos PA, Colosimo EA, Bousquet J. (Oct 2009). Monitoring adherence to beclomethasone in asthmatic children and adolescents through four different methods. Allergy, 64(10), 1458-62

BACKGROUND: Suboptimal adherence to inhaled steroids is a known problem in children and adolescents, even when medications are administered under parental supervision. This study aimed to verify the adherence rate to beclomethasone dipropionate (BDP) by four currently available methods. METHODS: In this concurrent cohort study, 102 randomly selected asthmatic children and adolescents aged 3-14 years were followed for 12 months. Adherence rate was assessed every 2 months by self and/or parent report, pharmacy dispensing data, electronic device (Doser); Meditrack Products, Hudson, MA, USA) monitor, and canister weight. RESULTS: Mean adherence rates to BDP by self and/or parent report, pharmacy records, Doser, and canister weight were 97.9% (95% CI 88.0-98.6), 70.0% (95% CI 67.6-72.4), 51.5% (95% CI 48.3-54.6), and 46.3% (95% CI 44.1-48.4), respectively. Agreement analysis between (Doser) and canister weight revealed a weighted kappa equal to 0.76 (95% CI 0.65-0.87). CONCLUSIONS: Adherence was a dynamic event and rates decreased progressively for all methods over the 12-month follow-up. Canister weight and electronic monitoring measures were more accurate than self/parent reports and pharmacy records. Rates obtained by these two methods were very close and statistical analysis also showed a substantial agreement between them. As measurements by canister weight are less costly compared with currently available electronic devices, it should be considered as an alternative method to assess adherence in both clinical research and practice.

Jiang H, Han J, Zhu Z, Xu W, Zheng J, Zhu Y. (Dec 2009). Patient compliance with assessing and monitoring of asthma. J Asthma, 46(10), 1027-31

BACKGROUND: The current asthma guidelines encourage use of a diary for assessing and monitoring symptoms and airway function. However, patient compliance and acceptability are usually poor owing to the burden of frequent and prolonged assessment. OBJECTIVE: We investigated whether better patient compliance could be ensured if a study was more relevant to patient convenience and had less impact on their daily life. METHODS: A total of 106 patients with symptomatic asthma underwent a fixed-time thrice-daily assessment schedule for a period lasting 2 weeks, and they were assigned to a doctor visit after the assessment. Symptoms and medication use were recorded in a booklet (paper diary) and airway function measured by a portable spirometer (electronic diary). RESULTS: Of 4,452 expected entries, the paper diary yielded 3,186 compliant entries and the electronic diary yielded 3,557 compliant entries; 71% of patients completed at least 30 compliant entries in the paper diary and 79% in the electronic diary. Use of an electronic device was associated with better compliance compared with paper technique (80.0% vs. 71.7%, p < 0.0001). Patient compliance decreased in the second week compared with the first week of diary keeping for both types of diaries (paper diary: 68.6% vs. 74.8%, p < 0.0001; electronic diary: 76.7% vs. 83.4%, p < 0.0001). The morning compliance was the least good, the afternoon better, and the evening best (paper diary: 68.2% vs. 71.0% vs. 75.9%, p < 0.0001; electronic diary: 77.2% vs. 79.0% vs. 83.9%, p < 0.0001). Among demographics and clinical factors, higher anxiety levels were linked to lower patient compliance. CONCLUSION: Good patient compliance and acceptability can be achieved when a study takes into account patient convenience, uses user friendly electronic devices, and is less disruptive to patients’ daily life.

Johnson EI, Sibon I, Renou P, Rouanet F, Allard M, Swendsen J. (Nov 2009). Feasibility and validity of computerized ambulatory monitoring in stroke patients. Neurology, 73(19), 1579-83

BACKGROUND: Computerized ambulatory monitoring provides real-time assessments of clinical outcomes in natural contexts, and it has been increasingly applied in recent years to investigate symptom expression in a wide range of disorders. The purpose of this study was to examine the feasibility and validity of this data collection strategy with adult stroke patients. METHODS: Forty-eight individuals (75% of the contacted sample) agreed to participate in the current study and were instructed to complete electronic interviews using a personal digital assistant 5 times per day over a 1-week period. RESULTS: More than 80% of programmed assessments were completed by the sample, and no evidence was found for fatigue effects. Expected patterns of associations were observed among daily life variables, and data collected through ambulatory monitoring were significantly correlated with standard clinic-based measures of similar constructs. CONCLUSION: Support was found for the feasibility and validity of computerized ambulatory monitoring with stroke patients. The application of these novel methods with stroke patients should provide complementary information that is inaccessible to standard hospital-based assessments and permit increased understanding of the significance of clinical results and test scores for daily life experience.

Jovanov E, Poon CC, Yang GZ, Zhang YT. (Nov 2009). Guest editorial. Body sensor networks: from theory to emerging applications. IEEE Trans Inf Technol Biomed, 13(6), 859-63.

The use of sensor networks for healthcare, well-being, and working in extreme environments has long roots in the engineering sector in medicine and biology community. With the maturity of wireless sensor networks, body area networks (BANs), and wireless BANs (WBANs), recent efforts in promoting the concept of body sensor networks (BSNs) aim to move beyond sensor connectivity to adopt a system-level approach to address issues related to biosensor design, interfacing, and embodiment, as well as ultralow-power processing/communication, power scavenging, autonomic sensing, data mining, inferencing, and integrated wireless sensor microsystems. As a result, the system architecture based on WBAN and BSN is becoming a widely accepted method of organization for ambulatory and ubiquitous monitoring systems. This editorial paper presents a snapshot of the current research and emerging applications and addresses some of the challenges and implementation issues.

Kaleth AS, Ang DC, Chakr R, Tong Y. (Aug 2009). Validity and reliability of community health activities model program for seniors and short-form international physical activity questionnaire as physical activity assessment tools in patients with fibromyalgia. Disabil Rehabil. [Epub ahead of print]

Purpose. There currently is a paucity of well-validated instruments to quantitatively measure physical activity (PA) levels in patients with fibromyalgia syndrome (FMS). This study aims to determine the construct validity and test-retest reliability of two self-report physical activity questionnaires [short-form international physical activity questionnaire (s-IPAQ) and community health activities model program for seniors (CHAMPS)] in a fibromyalgia population. Methods. Thirty subjects (mean age 49.1 +/- 9.6 years; 90% females) who met the American College of Rheumatology criteria for FMS were invited to participate in the study. Two-week test-retest reliability was evaluated for the CHAMPS and s-IPAQ. Construct validity was evaluated by comparing PA reported from these questionnaires with data obtained from accelerometry (steps/week, counts/week) and the 6-minute walk test (6-MWT). Results. CHAMPS showed greater test-retest reliability (r = 0.58; p < 0.001) compared with s-IPAQ (r = 0.18; p = 0.15). No significant correlations were observed between the self-report PA questionnaires and the 6-MWT or accelerometry data (p > 0.05). Conclusions. In a fibromyalgia population, the s-IPAQ does not appear to be a reliable and valid PA assessment tool. CHAMPS displayed moderate test-retest reliability; however, no associations were found between CHAMPS and objectives measures of PA. In view of the known benefits of exercise in patients with FMS, there is a need to develop new measures or validate other existing well-established PA questionnaires.

Kumahara H, Tanaka H, Schutz Y. (Dec 2009). Are pedometers adequate instruments for assessing energy expenditure? Eur J Clin Nutr, (12), 1425-32.

OBJECTIVE: Assessing energy expenditure (EE) is important for the control of obesity. Daily step counts have become popular and constitute one practical technique for evaluating the physical activity (PA) in large population studies. However, information on the capacity of pedometers to track EE in free-living conditions remains scanty. SUBJECTS AND METHODS: The 24-h EE of 71 healthy adults was measured by indirect calorimetry in a large respiratory chamber. Two accelerometers were attached to the waist, one for counting the total daily steps (ACC(STEP)) and another for measuring the anteroposterior whole body acceleration calculated as the root mean square of the acceleration signal at every second (ACC(RMS)). RESULTS: The ACC(STEP) was not associated with PA-related EE (PAEE) or 24-h EE. Body weight (BW) was the main determinant of both the values (explaining 30 and 75% of the variance, respectively). Approximately 8% (P<0.001) of the variance in PAEE was attributed to the ACC(RMS) after BW was accounted for, whereas the ACC(STEP) did not explain any additional variance. A multiple stepwise regression analysis revealed that BW, height and ACC(RMS) were highly significant determinants of 24-h EE and accounted for as much as 83% of the total variance. CONCLUSIONS: Recording the number of steps per day does not provide accurate information on EE, and at best is only a crude predictor of the general PA in terms of displacement. In contrast, accelerometry signals are considered to be a more meaningful factor in the assessment of EE rather than step counts under sedentary conditions.

Lee P, Abela JR, Auerbach R, Skitch S. J, Steele CM, Chau T. (Nov 2009). Swallow segmentation with artificial neural networks and multi-sensor fusion. Med Eng Phys, 31(9), 1049-55

Swallow segmentation is a critical precursory step to the analysis of swallowing signal characteristics. In an effort to automatically segment swallows, we investigated artificial neural networks (ANN) with information from cervical dual-axis accelerometry, submental MMG, and nasal airflow. Our objectives were (1) to investigate the relationship between segmentation performance and the number of signal sources and (2) to identify the signals or signal combinations most useful for swallow segmentation. Signals were acquired from 17 healthy adults in both discrete and continuous swallowing tasks using five stimuli. Training and test feature vectors were constructed with variances from single or multiple signals, estimated within 200 ms moving windows with 50% overlap. Corresponding binary target labels (swallow or non-swallow) were derived by manual segmentation. A separate 3-layer ANN was trained for each participant-signal combination, and all possible signal combinations were investigated. As more signal sources were included, segmentation performance improved in terms of sensitivity, specificity, accuracy, and adjusted accuracy. The combination of all four signal sources achieved the highest mean accuracy and adjusted accuracy of 88.5% and 89.6%, respectively. A-P accelerometry proved to be the most discriminatory source, while the inclusion of MMG or nasal airflow resulted in the least performance improvement. These findings suggest that an ANN, multi-sensor fusion approach to segmentation is worthy of further investigation in swallowing studies.

Lewandowski L, Rieger B, Smyth J, Perry L, Gathje R. (Dec 2009). Measuring post-concussion symptoms in adolescents: feasibility of ecological momentary assessment. Arch Clin Neuropsychol, 24(8), 791-6

Although there is a large literature examining head trauma in general, several areas remain understudied. Notably, little is known about symptom expression over the course of a day for adolescents recovering from concussion. Furthermore, intra-individual symptom variability has not been well characterized. This pilot study examined the feasibility of a momentary data-gathering method, as well as the sensitivity of the assessment to the subtle and dynamic changes in symptoms of concussion. Six adolescents, three of whom suffered a concussion and three non-injured controls, provided symptom ratings five times per day for 5 days. This ecological momentary assessment (EMA) was conducted on a personal digital assistant to capture variability in symptom reports while in the natural environment. Preliminary results indicated that the EMA method showed great promise as a research tool in natural settings (e.g., school and home). Adolescents were able to comply with all tasks with little interference in their daily activities. Students with concussion showed generally higher symptom ratings across physical, cognitive, and affective domains, and temporal and diurnal patterns for symptoms emerged. Implications for future research and patient care are discussed.

Litwin M, Simonetti GD, Niemirska A, Ruzicka M, Wühl E, Schaefer F, Feber J. (Dec 2009). Altered Cardiovascular Rhythmicity in Children with White Coat and Ambulatory Hypertension. Pediatr Res [Epub ahead of print]

Adults with ambulatory hypertension or white coat hypertension (WCH) display abnormal cardiovascular rhythms. We studied cardiovascular rhythms by Fourier analysis of 24h ambulatory blood pressure measurement profiles in 129 hypertensive children, 54 children with WCH and 146 age-, height- and gender-matched healthy subjects. The day/night mean arterial pressure ratio was lower in hypertensive and WCH patients compared to controls (1.13 vs. 1.16 vs. 1.21, respectively; p<0.0001). 85% of controls were dippers compared to 74% of WCH (n.s.) and 64% of ambulatory hypertensive patients (p<0.0001). The prevalence of 24h rhythms was similar among the groups but prevalence of 12h blood pressure rhythms was increased in hypertensive (67%) and WCH (72%) compared to controls (51%, p<0.0001). The amplitudes of the 24h, 8h, and 6h blood pressure rhythms were reduced in hypertensive and WCH compared to controls (p<0.05). Hypertensive and WCH patients displayed delayed 24h, 12h, 8h, 6h acrophases in comparison with controls (p<0.05). Concluding, hypertensive children exhibit abnormal cardiovascular rhythmicity compared to controls, especially a higher prevalence of non-dipping compared to normotensive children. Abnormalities in WCH patients are intermediate between healthy children and patients with ambulatory hypertension.

Loprinzi PD, Trost SG. (Dec 2009). Parental influences on physical activity behavior in preschool children. Prev Med [Epub ahead of print]

OBJECTIVE: To evaluate a conceptual model linking parent physical activity (PA) orientations, parental support for PA, and PA behavior in preschool children. METHODS: Participants were 156 parent-child dyads from 13 child care centers in Queensland, Australia. Parents completed a questionnaire measuring parental PA, parental enjoyment of PA, perceived importance of PA, parental support for PA, parents’ perceptions of competence, and child PA at home. MVPA while attending child care was measured via accelerometry. Data were collected between May and August of 2003. The relationships between the study variables and child PA were tested using observed variable path analysis. RESULTS: Parental PA and parents’ perceptions of competence were positively associated with parental support for PA (beta=0.23 and 0.18, respectively, p<0.05). Parental support, in turn, was positively associated with child PA at home (beta=0.16, p<0.05), but not at child care (beta=0.01, p=0.94). Parents’ perceptions of competence was positively associated with both home-based and child care PA (beta=0.20 and 0.28, respectively, p<0.05). CONCLUSIONS: Family-based interventions targeting preschoolers should include strategies to increase parental support for PA. Parents who perceive their child to have low physical competence should be encouraged to provide adequate support for PA.

Mendozzi L, Tronci F, Garegnani M, Pugnetti L. (Dec 2009). Sleep disturbance and fatigue in mild relapsing remitting multiple sclerosis patients on chronic immunomodulant therapy: an actigraphic study. Mult Scler [Epub ahead of print]

Background: poor sleep is common in MS and it contributes to fatigue. The beta interferons produce systemic effects which may not adapt and may induce fatigue. Objective: to verify whether subjective poor sleep and fatigue during chronic therapy correspond to reduced sleep efficiency obtained by actigraphy at home. Methods: 42 ambulatory relapsing remitting MS patients with mild disability were monitored for at least 7 nights. Habitual sleep quality and fatigue were assessed with the MOS sleep measure and the Fatigue Severity Scale. Sleep logs provided daily sleep quality assessments during actigraphy at home. Patients were grouped according to their current treatment: no therapy, glatiramer acetate, IFNbeta 3 times a week, and IFNbeta once a week. Results and Conclusion: sleep efficiency was reduced by an average of 5% in 2/3 of the nights following IFNbeta injections compared to the other nights, and daily sleep ratings correlated with actigraphy. Patients on glatiramer acetate also showed a lower sleep efficiency than patients without therapy. Actigraphy data were only modestly correlated with MOSsm scores, not with fatigue. Long term adaptation of sleep effects of immunomodulant agents is incomplete and needs to be considered in treatment planning and assessment of sleep in MS.

Miller J, Vachon DD, Lynam DR. (Dec 2009). Neuroticism, negative affect, and negative affect instability: Establishing convergent and discriminant validity using ecological momentary assessment. Personality and Individual Differences, 47(8), 873-877

Abstract: Few investigations have examined the role of affective instability within a broad model of general personality functioning. The present study employed self-report and ecological momentary assessments (EMA) to examine the relations between self-reported Five-Factor Model Neuroticism, EMA average negative affect, and EMA negative affect instability. Results suggest that Neuroticism and negative affect instability are related yet distinct constructs, and that Neuroticism better represents average negative affect across time. Results also suggest that negative affect instability is related to low Agreeableness and specific externalizing facets of Neuroticism, such as Angry Hostility and Impulsiveness. The implications of these findings and potential areas for future research are discussed.

Mohr C, Armeli S, Tennen H, Todd M. (Aug 2009). The complexities of modeling mood-drinking relationships: Lessons learned from daily process research. In: Substance abuse and emotion, 189-216

(from the chapter) Motivational models of alcohol consumption posit that adults drink to enhance positive experiences and to reduce the effects of negative experiences (Cooper, Frone, Russell, & Mudar, 1995; Cox & Klinger, 1988). The latter, referred to as drinking to cope (DTC) or tension-reduction drinking, is associated with alcohol-related problems (Cooper et al., 1995). Identifying and understanding DTC patterns is an important step in assessing and then preventing alcohol abuse. Although numerous cross-sectional or multiwave longitudinal studies have examined DTC, most have examined between-person associations of negative affect and drinking or have relied on individuals’ recall of their motivations, the reliability of which is questionable (e.g., Ptacek, Smith, Espe, & Raffety, 1994; Todd, Armeli, Tennen, Carney, & Affleck, 2003). Yet implicit in DTC theory is a dynamic process whereby negative events and emotions rapidly unfold and yield bidirectional influences with alcohol consumption, such that negative experiences increase alcohol consumption, which in turn increases negative experiences. Daily process designs in which events, emotions, and consumption are assessed close to the time they occur are uniquely suited to capturing these processes. Specifically, such studies address the question, Do individuals drink relatively more (or less) when they experience increases in stress and negative moods? Daily process studies have documented within-person negative mood-drinking associations in adult and college student populations, although results are often contradictory across studies. In this chapter, we briefly review daily process methodology and research findings from these studies related to tension-reduction drinking. We further explore the complexities of mood-drinking relationships by probing alternative analytical approaches, along with a consideration of within- and between-person moderators that may explicate when and for whom negative moods enhance alcohol consumption. We conclude with a discussion of the benefits and limitations of daily process methodology in assessing negative mood-related drinking (NMRD).

Mojza EJ, Lorenz C, Sonnentag S, Binnewies C (Dec 2009). Daily recovery experiences: The role of volunteer work during leisure time. Journal of Occupational Health Psychology, 15(1), 60-74

This study focused on the role of volunteer work for daily recovery from work. In a 1-week diary study with 166 employees, we assessed the amount of time spent on volunteer work during leisure time, and the recovery facets of psychological detachment from work (i.e., mentally switching off from work), mastery experiences (i.e., pursuing challenging activities), and community experiences (i.e., cultivating relationships) every day before participants went to bed. Results from hierarchical linear modeling (n = 529 days) showed volunteer work during leisure time to be positively related to mastery experiences and community experiences suggesting volunteer work to contribute to successful recovery by creating new resources.

Moliner-Urdiales D, Ruiz JR, Ortega FB, Rey-Lopez JP, Vicente-Rodriguez G, España-Romero V, Munguía-Izquierdo D, Castillo MJ, Sjöström M, Moreno LA; HELENA Study Group. (Oct 2009). Association of objectively assessed physical activity with total and central body fat in Spanish adolescents; the HELENA Study. Int J Obes (Lond), 33(10), 1126-35

OBJECTIVES: To examine the association of objectively assessed physical activity (PA) with markers of total and central body fat in adolescents, and to determine whether meeting the current PA recommendations (> or = 60 min day(-1) of at least moderate intensity PA) is associated with reduced levels of total and central body fat. SUBJECTS/METHODS: A total of 365 Spanish adolescents aged 12.5-17.5 years participated in this cross-sectional study. PA was assessed by accelerometry and expressed as average PA (counts per minute), and min day(-1) of light, moderate, moderate to vigorous (MVPA) and vigorous PA. MVPA was dichotomized into < 60 min day(-1) and > or = 60. Total body fat was measured by DXA, BodPod and the sum of six skinfolds. Central body fat was measured by DXA at three regions (R1, R2 and R3), and waist circumference. RESULTS: All markers of central body fat were negatively associated with vigorous PA (P < 0.01) after controlling for sex, age and pubertal status. Abdominal adiposity measured at R1, R2 and R3 was also negatively associated with MVPA (P < or = 0.001), and with average PA (P < 0.01). All markers of total body fat were negatively associated with vigorous PA (P < 0.01), MVPA (P < 0.01) and average PA (P < 0.05). Adolescents engaged on at least 60 min day(-1) MVPA presented lower levels of total (P < 0.05) and central body fat (P < or = 0.01). CONCLUSIONS: The results suggest that vigorous PA may have a greater effect on preventing obesity in adolescents than does PA of lower intensity, whereas both average PA and at least moderate PA may have an impact on total and central body fat in youth.

Munsch S, Meyer AH, Milenkovic N, Schlup B, Margraf J, Wilhelm FH. (Nov 2009). Ecological momentary assessment to evaluate cognitive-behavioral treatment for binge eating disorder. Int J Eat Disord, 42(7), 648-57

OBJECTIVE: Cognitive-behavioral treatment (CBT) for binge eating disorder (BED) is traditionally evaluated using clinical interviews and questionnaires. These retrospective assessment methods are discussed to be problematic due to memory recall error. Ecological momentary assessment (EMA) might be promising for gathering ecologically valid and reliable data. METHOD: We assessed the feasibility of and reactivity to EMA and compared the treatment efficacy measured by traditional vs. EMA-based instruments in 28 BED individuals participating in short-term CBT. RESULTS: Patients were highly compliant and we found no reactivity to EMA. Estimated treatment effects for binge eating based on EMA were comparable to questionnaire-based methods. The overall concordance between methods was moderate. DISCUSSION: Results suggest that binge eating over 1 week can be equally accurately assessed by EMA or by self-report questionnaires in BED treatment trials. EMA contributes to a detailed knowledge of binge eating in daily live and helps to advance treatment options.

Nock MK, Prinstein MJ, Sterba SK. (Nov 2009). Revealing the form and function of self-injurious thoughts and behaviors: A real-time ecological assessment study among adolescents and young adults. Journal of Abnormal Psychology, 118(4), 816-827

Self-injurious behaviors are among the leading causes of death worldwide. However, the basic nature of self-injurious thoughts and behaviors (SITBs) is not well understood because prior studies have relied on long-term, retrospective, aggregate, self-report assessment methods. The authors used ecological momentary assessment methods to measure suicidal and nonsuicidal SITBs as they naturally occur in real time. Participants were 30 adolescents and young adults with a recent history of self-injury who completed signal- and event-contingent assessments on handheld computers over a 14-day period, resulting in the collection of data on 1,262 thought and behavior episodes. Participants reported an average of 5.0 thoughts of nonsuicidal self-injury (NSSI) per week, most often of moderate intensity and short duration (1–30 min), and 1.6 episodes of NSSI per week. Suicidal thoughts occurred less frequently (1.1 per week), were of longer duration, and led to self-injurious behavior (i.e., suicide attempts) less often. Details are reported about the contexts in which SITBs most often occur (e.g., what participants were doing, who they were with, and what they were feeling before and after each episode). This study provides a first glimpse of how SITBs are experienced in everyday life and has significant implications for scientific and clinical work on self-injurious behaviors.

O’Driscoll DM, Foster AM, Davey MJ, Nixon GM, Horne RS. (Oct 2009) Can Actigraphy Measure Sleep Fragmentation in Children? Arch Dis Child [Epub ahead of print]

OBJECTIVE: The gold standard assessment for sleep quality is polysomnography (PSG). However, actigraphy has gained popularity as an ambulatory monitor. We aimed to assess the value of actigraphy in measuring sleep fragmentation in children. METHODS: 130 children aged 2-18y referred for assessment for sleep disordered breathing (SDB) were recruited. The arousal index (AI) scored from PSG was compared to the actigraphic fragmentation index (FI) and number of wake bouts/h. RESULTS: The ability of actigraphic measures to correctly classify a child as having an AI>10 events/h rated as fair for the FI, and poor for wake bouts/h (area under the ROC curve, 0.73 and 0.67 respectively). CONCLUSION: Actigraphy provides only a fair indication of the level of arousal from sleep in children. While the limitations of actigraphy prevent it from being a diagnostic tool for SDB, it still has a role in evaluating sleep/wake schedules in children.

Ooorschot M, Kwapil T, Delespaul P, Myin-Germeys I. (Dec 2009). Momentary assessment research in psychosis. Psychological Assessment, 21(4), 498-505

There is an expanding interest to study psychosis in the realm of daily life. The study of the person in the context of daily life may provide a powerful addition to more conventional and cross-sectional research strategies in the study of psychosis. This article first discusses the nature of experience sampling research in psychosis and demonstrates the feasibility and validity of studies using the experience sampling method (ESM) in this patient group. Second, the article presents a review of all ESM research in psychosis with a special focus on (a) the phenomenology, (b) the etiology, and (c) psychological models of psychosis. Variability over time and the dynamic interplay with the environment were found to be essential features of the positive symptoms of psychosis, whereas behavioral patterns as well as self-reported affect in daily life reality might be essential when studying negative symptomatology. ESM contributes to a better understanding of the interplay between psychotic experiences and environmental features, such as stress or cannabis exposure. Finally, the study of symptomatic variability may fuel new research into psychological models and treatment of psychosis and the study of the person–environment interplay may foster new Gene × Environment interaction studies.

O’Toole JE, Sinclair MI, Leder K. (Nov 2009). Collecting household water usage data: telephone questionnaire or diary? BMC Med Res Methodol, 9, 9:72

BACKGROUND: Quantitative Microbial Risk Assessment (QMRA), a modelling approach, is used to assess health risks. Inputs into the QMRA process include data that characterise the intensity, frequency and duration of exposure to risk(s). Data gaps for water exposure assessment include the duration and frequency of urban non-potable (non-drinking) water use. The primary objective of this study was to compare household water usage results obtained using two data collection tools, a computer assisted telephone interview (CATI) and a 7-day water activity diary, in order to assess the effect of different methodological survey approaches on derived exposure estimates. Costs and logistical aspects of each data collection tool were also examined. METHODS: A total of 232 households in an Australian dual reticulation scheme (where households are supplied with two grades of water through separate pipe networks) were surveyed about their water usage using both a CATI and a 7-day diary. Householders were questioned about their use of recycled water for toilet flushing, garden watering and other outdoor activities. Householders were also questioned about their water use in the laundry. Agreement between reported CATI and diary water usage responses was assessed. RESULTS: Results of this study showed that the level of agreement between CATI and diary responses was greater for more frequent water-related activities except toilet flushing and for those activities where standard durations or settings were employed. In addition, this study showed that the unit cost of diary administration was greater than for the CATI, excluding consideration of the initial selection and recruitment steps. CONCLUSION: This study showed that it is possible to successfully ‘remotely’ coordinate diary completion providing that adequate instructions are given and that diary recording forms are well designed. In addition, good diary return rates can be achieved using a monetary incentive and the diary format allows for collective recording, rather than an individual’s estimation, of household water usage. Accordingly, there is merit in further exploring the use of diaries for collection of water usage information either in combination with a mail out for recruitment, or potentially in the future with Internet-based recruitment (as household Internet uptake increases).

Paez S, Maloney A, Kelsey K, Wiesen C, Rosenberg A. (Fall 2009). Parental and environmental factors associated with physical activity among children participating in an active video game. Pediatr Phys Ther, 21(3), 245-53

PURPOSE: Parental and intervention-specific environmental supports were examined as potential reinforcers for physical activity and use of a video game, Dance Dance Revolution (DDR), among a cohort of 7- to 8-year-old children. METHODS: Sixty children were randomized to an intervention (n = 40) or a control (n = 20) group. Physical activity was measured with accelerometry and DDR logs. Parental support for their child’s physical activity was assessed via a questionnaire. DDR-specific environmental supports were captured on an environmental home screen and the DDR log. RESULTS: At baseline, the absence of other video games and parent DDR participation was associated with child participation in DDR. At follow-up, DDR participation of siblings and friends was associated with child participation in DDR. CONCLUSION: The primary findings of this study suggest that parental and peer participation in DDR may play a role in children’s initial and sustained participation in DDR.

Papp LM, Pendry P, Adam EK. (Dec 2009). Mother-adolescent physiological synchrony in naturalistic settings: Within-family cortisol associations and moderators. Journal of Family Psychology, 23(6), 882-894

In this study, the authors examined parent-adolescent cortisol associations in 45 families with adolescent children (24 girls; M age = 15.78 years, SD = 1.44 years). Family members’ salivary cortisol levels were measured seven times a day on 2 typical weekdays. Family members provided reports of demographic and health variables, and adolescents rated parent-child relationship characteristics. After accounting for the effects of time of day and relevant demographic and health control variables on cortisol levels, hierarchical linear models indicated the presence of significant covariation over time in mother-adolescent cortisol (i.e., physiological synchrony). Furthermore, moderating tests revealed that mother-adolescent cortisol synchrony was strengthened among dyads characterized by mothers and adolescents spending more time together, and in families rated higher on levels of parent-youth shared activities and parental monitoring or supervision. Analysis of momentary characteristics indicated that maternal presence at the time of cortisol sampling lowered adolescent cortisol levels but did not account for mother-adolescent cortisol synchrony. Within-family physiological synchrony was amplified in momentary contexts of elevated maternal negative affect and elevated adolescent negative affect

Park MJ, Kim HS, Kim KS. (Oct 2009). Cellular phone and Internet-based individual intervention on blood pressure and obesity in obese patients with hypertension. Int J Med Inform, 78(10), 704-10

PURPOSE: The present study evaluated whether an intervention using a short message service (SMS) by cellular phone and Internet would improve blood pressure, weight control, and serum lipids of obese patients with hypertension during 8 weeks. METHODS: This is a quasi-experimental design with pre- and follow-up tests. Participants were recruited from the family medicine outpatient department of tertiary care hospital located in an urban city of South Korea. Twenty-eight patients were assigned to an intervention group and 21 to a control group. The goal of intervention was to bring blood pressure, body weight, and serum lipids levels close to normal ranges. Patients in the intervention group were requested to record their blood pressure and body weight in a weekly web based diary through the Internet or by cellular phones. The researchers sent optimal recommendations as an intervention to each patient, by both cellular phone and Internet weekly. The intervention was applied for 8 weeks. RESULTS: Systolic (SBP) and diastolic blood pressures (DBP) significantly decreased by 9.1 and 7.2 mmHg respectively at 8 weeks from the baseline in the intervention group (p<0.05). However, after 8 weeks from the baseline both SBP and DBP in the control group had not changed significantly. Yet, There were significant mean decreases in body weight and waist circumference by 1.6 kg (p<0.05) and 2.8 cm (p<0.05) in the intervention group, respectively. In the control group increases in body weight and waist circumference (p<0.05) mean changes were also significant. High density lipoprotein cholesterol (HDL-C) significantly increased, with a mean change of 3.7 mg/dl at 8 weeks from baseline in the intervention group (p<0.05). The mean change of HDL-C in the control group was, however, not significant. CONCLUSION: During 8 weeks using this web-based intervention by way of cellular phone and Internet SMS improved blood pressure, body weight, waist circumference, and HDL-C in patients with obese hypertension.

Pfaltz MC, Michael T, Grossman P, Blechert J, Wilhelm FH. (Oct 2009). Respiratory pathophysiology of panic disorder: an ambulatory monitoring study. Psychosom Med, 71(8), 869-76

OBJECTIVE: To assess the external validity of laboratory baselines in panic disorder (PD), frequently associated with respiratory pattern abnormalities like increased respiratory variability and sighing, implying a stable pathophysiologic trait characteristic. METHODS: Physical activity and a variety of breath-by-breath volumetric, timing, and variability measures of respiration were recorded in the daily life of 26 patients with PD and 26 healthy controls (HC), using a novel ambulatory monitoring system optimized for reliable assessment of respiratory pattern. Data were stratified for physical activity to eliminate its confounding effects. RESULTS: Groups showed strong and consistent diurnal patterns in almost all respiratory variables. However, patients with PD did not differ from HC regarding any of the respiratory timing, volumetric and variability measures, with negligible group effect sizes for all measures. Patients with fewer self-reported respiratory symptoms of anxiety exhibited more pronounced rapid shallow breathing as well as diminished total breath time and its variability. CONCLUSIONS: Despite state-of-the-art ambulatory assessment and sufficient statistical power to detect respiratory alterations previously observed in the laboratory, we found no evidence for such alterations in PD patients’ daily life. Neither the total PD group nor patients with particularly pronounced respiratory symptomatology displayed increased respiratory variability. These results caution against interpreting results from laboratory baselines in PD as reflecting a stable trait characteristic. Rather, they likely represent a state-trait interaction due to enhanced reactivity of PD patients to novel environments. These results challenge aspects of respiratory theories of PD that were based on laboratory findings.

Pitetti KH, Beets MW, Flaming J. (Oct 2009). Accuracy of pedometer steps and time for youth with intellectual disabilities during dynamic movements. Adapt Phys Activ Q, 26(4), 336-51

Pedometer accuracy for steps and activity time during dynamic movement for youth with intellectual disabilities (ID) were examined. Twenty-four youth with ID (13 girls, 13.1 +/- 3.2 yrs; 11 boys, 14.7 +/- 2.7 yrs) were videotaped during adapted physical education class while wearing a Walk4Life 2505 pedometer in five locations around the waist. Researchers viewed each videotape and recorded observed steps and activity time. Observed findings were compared with pedometer recorded steps and time. On average, pedometer registered steps were underestimated by approximately 14% +/- 16.5%, whereas pedometer registered time was overestimated by approximately 8.7% +/- 21.8%. The findings indicate that the accuracy of pedometers may be compromised during dynamic movement for youth with ID.

Poh CH, Gasiorowska A, Allen L, Navarro-Rodriguez T, Mizyed I, Powers J, Moty B, Quan SF, Willis MR, Ashpole N, Malagon I, Fass R. (Nov 2009). Reassessment of the Principal Characteristics of Gastroesophageal Reflux During the Recumbent Period Using Integrated Actigraphy-Acquired Information. Am J Gastroenterol [Epub ahead of print]

OBJECTIVES:Characterization of gastroesophageal reflux (GERD) events during the sleep period has been hampered by lack of any patient-friendly technique that allows accurate assessment of sleep duration and awakening time, without confining patients to a sleep laboratory. Our aim was to compare principal reflux characteristics during the upright, recumbent-awake, and recumbent-asleep periods as well as to determine the effect of sleep awakenings on the principal reflux characteristics of the recumbent-asleep period using novel technology that allows integration of recorded actigraphy data into collected pH information.METHODS:Patients with heartburn at least three times a week for the previous 3 months were invited to participate in this study. All participants were evaluated by the demographics and the GERD Symptom Checklist questionnaires. Thereafter, patients underwent ambulatory 24-h esophageal pH monitoring concomitantly with actigraphy. A novel technique was used to superimpose simultaneously recorded raw actigraphy data over pH data, resulting in more accurate information about reflux events during upright, recumbent-awake, recumbent-asleep, and conscious awakening periods as well as the relationship between symptoms and acid reflux events in the aforementioned periods.RESULTS:Thirty-nine subjects (M/F: 26/13, mean age 56.6+/-14 years) with an abnormal pH test were enrolled into the study. The recumbent period appeared heterogeneous and was clearly divided into recumbent-awake (123.0+/-20.2 min) and recumbent-asleep (485.6+/-23.6 min) periods. The percent total time pH<4, the mean number of acid reflux events, and the number of symptoms associated with reflux events were significantly greater in the recumbent-awake as compared with the recumbent-asleep period. The mean duration of an acid reflux event was not different among upright, recumbent-awake, and recumbent-asleep periods. However, short-duration reflux events during the sleep period were associated with conscious awakenings as compared with those during sleep (0.74+/-0.11 min vs. 1.64+/-0.3 min, P=0.01).CONCLUSIONS:The recumbent period is divided into recumbent-awake and recumbent-asleep periods. The recumbent-awake period has significantly different principal reflux characteristics than the recumbent-asleep period. Duration of an acid reflux event during the recumbent-asleep period is not uniformly prolonged. Short-duration acid reflux events during the sleep period are likely due to conscious awakenings.

Preston Preston KL, Vahabzadeh M, Schmittner J, Lin J-L, Gorelick DA, Epstein DH. (Dec 2009). Cocaine craving and use during daily life. Psychopharmacology, 207(2), 291-301

Rationale: Craving is often assumed to cause ongoing drug use and relapse and is a major focus of addiction research. However, its relationship to drug use has not been adequately documented. Objectives: The aim of this study was to investigate the relationship between craving and drug use in real time and in the daily living environments of drug users. Methods: In a prospective, longitudinal, cohort design (ecological momentary assessment), 112 cocaine-abusing individuals in methadone maintenance treatment rated their craving and mood at random times (two to five times daily, prompted by electronic diaries) as they went about their everyday activities. They also initiated an electronic diary entry each time they used cocaine. Drug use was monitored by thrice-weekly urine testing. Results: During periods of urine-verified cocaine use, ratings of cocaine craving increased across the day and were higher than during periods of urine-verified abstinence. During the 5 h prior to cocaine use, ratings of craving significantly increased. These patterns were not seen in ratings of heroin craving or mood (e.g., feeling happy or bored). Conclusions: Cocaine craving is tightly coupled to cocaine use in users’ normal environments. Our findings provide previously unavailable support for a relationship that has been seriously questioned in some theoretical accounts. We discuss what steps will be needed to determine whether craving causes use.

Ram N, Gerstorf D. (Dec 2009). Time-structured and net intraindividual variability: Tools for examining the development of dynamic characteristics and processes. Psychology and Aging, 24(4), 778-791

The study of intraindividual variability is the study of fluctuations, oscillations, adaptations, and “noise” in behavioral outcomes that manifest on microtime scales. This article provides a descriptive frame for the combined study of intraindividual variability and aging/development. At the conceptual level, we show that the study of intraindividual variability provides access to dynamic characteristics - construct-level descriptions of individuals’ capacities for change (e.g., lability)—and to dynamic processes—the systematic changes that individuals exhibit in response to endogenous and exogenous influences (e.g., regulation). At the methodological level, we review how quantifications of net intraindividual variability and models of time-structured intraindividual variability are used to measure and describe dynamic characteristics and processes. At the research design level, we point to the benefits of measurement-burst study designs, wherein data are obtained across multiple time scales, for the study of development.

Rawson ES, Walsh TM. (Nov 2009). Estimation of Resistance Exercise Energy Expenditure using Accelerometry. Med Sci Sports Exerc [Epub ahead of print]

Resistance exercise is recommended by the major health and sports medicine organizations to maintain good health, but resistance exercise energy expenditure is difficult to measure. Accelerometers offer a viable alternative to estimate energy expenditure during resistance exercise, as they are cost-effective and do not restrict motion or exercise choice. PURPOSE:: To estimate resistance exercise energy expenditure using accelerometry, and to determine if there are differences in counts of activity during resistance exercise based on accelerometer location. Methods: Thirty men and women (21.6 years) performed 2 sets of 10 repetitions of each of 8 exercises. During the exercise protocol, participants wore accelerometers (ActiGraph GT1M) on the wrist, waist, and ankle and a portable metabolic system (CosMed K4b). METHODS:: Thirty men and women (21.6 years) performed 2 sets of 10 repetitions of each of 8 exercises. During the exercise protocol, participants wore accelerometers (ActiGraph GT1M) on the wrist, waist, and ankle and a portable metabolic system (CosMed K4b). RESULTS:: Activity counts (mean +/- SD) were different between the wrist (61,282 +/- 8358), ankle (26,886 +/- 3998), and waist (6565 +/- 2445). Resistance exercise energy expenditure was significantly associated with ankle (r=0.50; p<0.01) and waist (r=0.77; p<0.001) accelerometer counts, and there was a trend for an association between resistance exercise energy expenditure and wrist accelerometer counts (r=0.31; p=0.10). Total waist accelerometer counts explained 59% of the variance (R = 0.59) in energy expenditure. A regression equation to predict resistance exercise energy expenditure including sex, fat free mass, and counts of activity from the waist accelerometer explained 90% (R=0.90) of the variance in energy expenditure. CONCLUSION: Resistance exercise energy expenditure can be estimated using a uni-axial accelerometer worn at the waist, and sex and fat free mass of the participant.

Riddoch CJ, Leary SD, Ness AR, Blair SN, Deere K, Mattocks C, Griffiths A, Davey Smith G, Tilling K. (Nov 2009). Prospective associations between objective measures of physical activity and fat mass in 12-14 year old children: the Avon Longitudinal Study of Parents and Children (ALSPAC). BMJ, 339:b4544

OBJECTIVE: To investigate associations between physical activity at age 12 and subsequent adiposity at age 14. DESIGN: Prospective birth cohort study with data collected between 2003 and 2007. SETTING: Original recruitment in 1991-2 of 14,541 pregnant women living in the former County of Avon (United Kingdom). PARTICIPANTS: At age 12, 11,952 children were invited to attend the research clinic. Of these, 7159 attended, and 4150 (1964 boys, 2186 girls) provided sufficient data on exposure, outcome, and confounding variables. MAIN OUTCOME MEASURE: Fat mass at age 14, measured by dual emission x ray absorptiometry, associated with physical activity at age 12, measured by accelerometry. RESULTS: Prospective associations of fat mass at age 14 (outcome) with physical activity at age 12 (exposure) were strong for both total activity (accelerometer counts/min) and for daily amount of moderate-vigorous physical activity (min/day). An extra 15 minutes of moderate-vigorous physical activity per day at age 12 was associated with lower fat mass at age 14 in boys (by 11.9% (95% confidence interval 9.5% to 14.3%)) and girls (by 9.8% (6.7% to 12.8%)). The proportion of physical activity due to moderate-vigorous physical activity was between 20% and 30% in boys and girls at the two ages. CONCLUSIONS: Higher levels of physical activity, in particular activity of moderate to higher intensities, are prospectively associated with lower levels of fat mass in early adolescence. Interventions to raise levels of physical activity in children are likely to be important in the fight against obesity.

Ridgers ND, Tóth M, Uvacsek M. (Nov 2009). Physical activity levels of Hungarian children during school recess. Prev Med, 49(5), 410-2

OBJECTIVE: The purpose of this study was to examine physical activity levels and patterns of physical activity across daily school recess periods, and the contribution of recess to daily physical activity. METHOD: Ninety-eight children (61% boys) from three schools in Hungary had their physical activity quantified using uni-axial accelerometry every 5 s for three consecutive school days (Wednesday to Friday). The proportion of time spent in sedentary, light, moderate-to-vigorous, and vigorous physical activity during 5 daily school recess periods was determined using existing age-appropriate cut-points. The relative contribution of recess to daily moderate-to-vigorous physical activity was also determined. Data were collected between May and October 2008. RESULTS: Boys engaged in significantly more light (30.6+/-5.2%; 27.7+/-5.1%), moderate-to-vigorous (24.9+/-8.9%; 17.5+/-5.2%) and vigorous physical activity (7.6+/-4.7%; 4.3+/-2.9%) than girls during recess. Girls (54.8+/-8.1%) engaged in more sedentary activity than boys (44.5+/-10.2%). Physical activity levels were generally similar across multiple recess periods. Recess contributed more moderate-to-vigorous physical activity towards weekday physical activity for boys (13.1%) than girls (10.8%). CONCLUSIONS: Since sedentary activity accounted for the largest proportion of recess, interventions may be needed across all recess periods to promote physical activity during the school day.

Röcke C, Li SC, Smith J. (Dec 2009). Intraindividual variability in positive and negative affect over 45 days: Do older adults fluctuate less than young adults? Psychology and Aging, 24(4), 863-878

Opposing scenarios about age-related increases and decreases in intraindividual variability are found in the literature: Whereas accumulating evidence indicates that cognitive functioning is characterized by an age-related increase of short-term variability, age-related decreases in variability could be expected in affective states on the basis of theories of emotion regulation and self development. We examined age differences in intraindividual variability of positive affect (PA) and negative affect (NA) and in contingencies among daily affect, daily stress, and daily events using up to 45 daily assessments of 18 young (20–30 years) and 19 older (70–80 years) adults. Whereas age groups differed little in average affect levels, older adults showed significantly less variability in PA and NA than young adults. Age differences accounted for greater variance in variability than personality factors. Multilevel modeling indicated that for young but not older adults, PA was higher (lower) on days with a positive (negative) event, and NA was lower on days with a positive event. There were no age differences in daily affect reactivity to appraised stress severity.

Rodell JB, Judge TA. (Nov 2009). Can “good” stressors spark “bad” behaviors? The mediating role of emotions in links of challenge and hindrance stressors with citizenship and counterproductive behaviors. Journal of Applied Psychology, 94(6), 1438-1451

The authors combined affective events theory (H. M. Weiss & Cropanzano, 1996) and the transactional stress model (R. S. Lazarus & Folkman, 1984) to build and test a model specifying the dynamic, emotion-based relationships among challenge and hindrance stressors and citizenship and counterproductive behaviors. The study employed an experience sampling methodology. Results showed that challenge stressors had offsetting indirect links with citizenship behaviors through attentiveness and anxiety and a positive indirect effect on counterproductive behaviors through anxiety. Hindrance stressors had a negative indirect effect on citizenship behaviors through anxiety and a positive indirect effect on counterproductive behaviors through anxiety and anger. Finally, multilevel moderating effects showed that the relationship between hindrance stressors and anger varied according to employees’ levels of neuroticism.

Rofey DL, Hull EE, Phillips J, Vogt K, Silk JS, Dahl RE. (Dec 2009). Utilizing Ecological Momentary Assessment in Pediatric Obesity to Quantify Behavior, Emotion, and Sleep. Obesity (Silver Spring) [Epub ahead of print]

The authors combined affective events theory (H. M. Weiss & Cropanzano, 1996) and the transactional stress model (R. S. Lazarus & Folkman, 1984) to build and test a model specifying the dynamic, emotion-based relationships among challenge and hindrance stressors and citizenship and counterproductive behaviors. The study employed an experience sampling methodology. Results showed that challenge stressors had offsetting indirect links with citizenship behaviors through attentiveness and anxiety and a positive indirect effect on counterproductive behaviors through anxiety. Hindrance stressors had a negative indirect effect on citizenship behaviors through anxiety and a positive indirect effect on counterproductive behaviors through anxiety and anger. Finally, multilevel moderating effects showed that the relationship between hindrance stressors and anger varied according to employees’ levels of neuroticism.

Sayk F, Teckentrup C, Becker C, Heutling D, Wellhöner P, Lehnert H, Dodt C. (Nov 2009). Effects of selective slow-wave sleep deprivation on nocturnal blood pressure dipping and daytime blood pressure regulation. Am J Physiol Regul Integr Comp Physiol, 298(1), R191-7

Nocturnal blood pressure (BP) decline or “dipping” is an active, central, nervously governed process, which is important for BP regulation during daytime. It is, however, not known whether the sleep process itself or, more specifically, slow-wave sleep (SWS) is important for normal dipping. Therefore, in the present study, healthy subjects (6 females, 5 males) were selectively deprived of SWS by EEG-guided acoustic arousals. BP and heart rate (HR) were monitored during experimental nights and the following day. Additionally, nocturnal catecholamine excretion was determined, and morning baroreflex function was assessed by microneurographic measurements of muscle sympathetic nerve activity (MSNA) and heart rate variability (HRV). Data were compared with a crossover condition of undisturbed sleep. SWS was successfully deprived leading to significantly attenuated mean arterial BP dipping during the first half (P < 0.05), but not during the rapid-eye-movement-dominated second half of total sleep; however, dipping still evolved even in the absence of SWS. No differences were found for nighttime catecholamine excretion. Moreover, daytime resting and ambulatory BP and HR were not altered, and morning MSNA and HRV did not differ significantly, indicating that baroreflex-mediated sympathoneural BP regulation was not affected by the preceding SWS deprivation. We conclude that in healthy humans the magnitude of nocturnal BP dipping is significantly affected by sleep depth. Deprivation of SWS during one night does not modulate the morning threshold and sensitivity of the vascular and cardiac baroreflex and does not alter ambulatory BP during daytime.

Schmidt MD, Cleland VJ, Shaw K, Dwyer T, Venn AJ. (Oct 2009). Cardiometabolic risk in younger and older adults across an index of ambulatory activity. Am J Prev Med 37(4), 278-84

Pedometers are increasingly being used to assess population levels of physical activity and as motivational tools for individuals to increase their physical activity. To maximize their utility, a framework for classifying pedometer-determined activity into meaningful health-related categories is needed. PURPOSE: This study investigated whether a pedometer step index proposed by Tudor-Locke and Bassett can effectively group younger and older adults according to cardiometabolic health status. METHODS: Analyses (conducted in 2008) used cross-sectional data from the Childhood Determinants of Adult Health study (1793 adults aged 26-36 years; collected 2004-2006) and from the Tasmanian Older Adult Cohort study (1014 adults aged 50-80 years; collected 2002-2006). Participants wore a pedometer for 7 days and the prevalence of cardiometabolic health indicators, including the metabolic syndrome, elevated Pathobiological Determinants of Atherosclerosis in Youth risk scores, and elevated Framingham risk scores, was examined across the following step categories: sedentary (< 5000); low-active (5000-7499); somewhat active (7500-9999); active (10,000-12,499); and high-active (> or = 12,500). RESULTS: With the exception of younger men, individuals achieving > or = 5000 steps had a substantially lower prevalence of adverse cardiometabolic health indicators than those obtaining fewer steps. Differences in the prevalence of adverse indicators were generally modest across higher steps-per-day categories. However, younger men and women in the high-active category had a substantially lower prevalence of some adverse health indicators. CONCLUSIONS: In general, the proposed index for classifying pedometer activity effectively distinguishes cardiometabolic health risk. Pedometers may be a useful tool for objectively identifying inactive individuals at greatest risk for poor cardiometabolic health.

Schulz MS, Waldinger RJ. (Jan 2010). Capturing the elusive: Studying emotion processes in couple relationships. In: Strengthening couple relationships for optimal child development: Lessons from research and intervention. Schulz, MS (Ed.), Pruett MK (Ed.), Kerig PK (Ed.), Parke RD (Ed.); Washington, DC, US: American Psychological Association, 131-147

(from the chapter) In this chapter, we describe our efforts to study emotion processes in couple interactions using multiple approaches and multiple windows of observation. We begin by briefly embedding these efforts in the larger context of research and theory on emotion processes in couples. We then discuss modern theories of emotion and note the challenges that these theories present for investigators. Finally, we review approaches to addressing major challenges in emotion research using examples from the field and from our own studies of couple interactions. These challenges include how to study emotion in ecologically valid situations; how to capture fleeting emotional experiences, including associated cognitive and motivational elements; how to reliably and sensitively assess emotion expression; and how to track and integrate multiple aspects of emotion (e.g., physiology, subjective feeling states, observed expression) as they unfold over time.

Sejdic E, Steele CM, Chau T. (Nov 2009). A procedure for denoising dual-axis swallowing accelerometry signals. Physiol Meas, 31(1), N1-9

Dual-axis swallowing accelerometry is an emerging tool for the assessment of dysphagia (swallowing difficulties). These signals however can be very noisy as a result of physiological and motion artifacts. In this note, we propose a novel scheme for denoising those signals, i.e. a computationally efficient search for the optimal denoising threshold within a reduced wavelet subspace. To determine a viable subspace, the algorithm relies on the minimum value of the estimated upper bound for the reconstruction error. A numerical analysis of the proposed scheme using synthetic test signals demonstrated that the proposed scheme is computationally more efficient than minimum noiseless description length (MNDL)-based denoising. It also yields smaller reconstruction errors than MNDL, SURE and Donoho denoising methods. When applied to dual-axis swallowing accelerometry signals, the proposed scheme exhibits improved performance for dry, wet and wet chin tuck swallows. These results are important for the further development of medical devices based on dual-axis swallowing accelerometry signals.

Shaban H, Abou El-Nasr M, Buehrer R. (Dez 2009). Towards a Highly Accurate Ambulatory System for Clinical Gait Analysis via UWB Radios. IEEE Trans Inf Technol Biomed.. [Epub ahead of print]

In this paper, we propose and investigate a lowcost and low-complexity wireless ambulatory human locomotion tracking system that provides a high ranging accuracy (intersensor distance) suitable for the assessment of clinical gait analysis using wearable ultra-wideband (UWB) transceivers. The system design and transceiver performance are presented in additive white Gaussian noise (AWGN) and realistic channels, using industry accepted channel models for body area networks. The proposed system is theoretically capable of providing a ranging accuracy of 0.11cm error at distances equivalent to inter-marker distances, at an 18dB signal-to-noise-ratio (SNR) in realistic onbody UWB channels. Based on real measurements, it provides the target ranging accuracy at an SNR=20dB. The achievable accuracy is ten times better than the accuracy reported in the literature for the inter-marker distance measurement. This makes it suitable for use in clinical gait analysis, and for the characterization and assessment of unstable mobility diseases, such as Parkinsons disease.

Shiffman S. (Dez 2009). Ecological momentary assessment (EMA) in studies of substance use. Psychological Assessment, 21(4), 486-497

Ecological momentary assessment (EMA) is particularly suitable for studying substance use, because use is episodic and thought to be related to mood and context. This article reviews EMA methods in substance use research, focusing on tobacco and alcohol use and relapse, where EMA has been most applied. Common EMA designs combine event-based reports of substance use with time-based assessments. Approaches to data organization and analysis have been very diverse, particularly regarding their treatment of time. Compliance with signaled assessments is often high. Compliance with recording of substance use appears good but is harder to validate. Treatment applications of EMA are emerging. EMA captures substance use patterns not measured by questionnaires or retrospective data and holds promise for substance use research.

Soares-Miranda L, Sandercock G, Valente H, Vale S, Santos R, Mota J. (Dez 2009). Vigorous physical activity and vagal modulation in young adults. Eur J Cardiovasc Prev Rehabil, 16(6), 705-11

BACKGROUND: Aerobic exercise leads to reduced sympathetic and increased cardiac vagal modulation, providing an antiarrhythmic effect. The optimal exercise intensity to promote this adaptation remains undefined. The aims of the present investigation were twofold. First, to examine differences in heart rate variability (HRV) measures in participants with different levels of objectively measured physical activity (PA). Second, to identify the characteristic of PA which most influences the cardiac autonomic nervous system (cANS) function in young adults. METHODS: Cross-sectional evaluation of 84 adults examining relationships between PA amount and intensities, measured by accelerometry, cANS function derived from HRV. Groups were created based on tertiles of PA and analysis of covariance was used to assess between-group differences in HRV. Stepwise regression analysis was used to determine the characteristic of PA, which best predicted vagal HRV indices. RESULTS: There were significantly higher levels of vagal HRV indices in the most active group compared with the least active group. Regression analysis revealed that the number of bouts of vigorous PA undertaken was the best predictor of the vagal HRV indices assessed. CONCLUSION: This study suggests that vagal modulation is enhanced with high levels of PA and that it is the number of bouts of vigorous PA that is most closely associated with cANS function.

Staudenmayer J, Pober D, Crouter S, Bassett D, Freedson P. (Oct 2009). An artificial neural network to estimate physical activity energy expenditure and identify physical activity type from an accelerometer. J Appl Physiol, 107(4), 1300-7

The aim of this investigation was to develop and test two artificial neural networks (ANN) to apply to physical activity data collected with a commonly used uniaxial accelerometer. The first ANN model estimated physical activity metabolic equivalents (METs), and the second ANN identified activity type. Subjects (n = 24 men and 24 women, mean age = 35 yr) completed a menu of activities that included sedentary, light, moderate, and vigorous intensities, and each activity was performed for 10 min. There were three different activity menus, and 20 participants completed each menu. Oxygen consumption (in ml x kg(-1) x min(-1)) was measured continuously, and the average of minutes 4-9 was used to represent the oxygen cost of each activity. To calculate METs, activity oxygen consumption was divided by 3.5 ml x kg(-1) x min(-1) (1 MET). Accelerometer data were collected second by second using the Actigraph model 7164. For the analysis, we used the distribution of counts (10th, 25th, 50th, 75th, and 90th percentiles of a minute’s second-by-second counts) and temporal dynamics of counts (lag, one autocorrelation) as the accelerometer feature inputs to the ANN. To examine model performance, we used the leave-one-out cross-validation technique. The ANN prediction of METs root-mean-squared error was 1.22 METs (confidence interval: 1.14-1.30). For the prediction of activity type, the ANN correctly classified activity type 88.8% of the time (confidence interval: 86.4-91.2%). Activity types were low-level activities, locomotion, vigorous sports, and household activities/other activities. This novel approach of applying ANNs for processing Actigraph accelerometer data is promising and shows that we can successfully estimate activity METs and identify activity type using ANN analytic procedures.

Steele RM, van Sluijs EM, Cassidy A, Griffin SJ, Ekelund U. (Nov 2009). Targeting sedentary time or moderate- and vigorous-intensity activity: independent relations with adiposity in a population-based sample of 10-y-old British children. Am J Clin Nutr, 90(5), 1185-92

BACKGROUND: It is unclear whether subcomponents of physical activity (PA) are associated with adiposity independent of time spent while sedentary. OBJECTIVE: The objective was to examine associations between objectively measured PA and its subcomponents [ie, time spent at light-intensity PA, moderate-intensity PA (MPA), vigorous-intensity PA (VPA), and moderate-plus-vigorous-intensity PA (MVPA)], independent of sedentary time, and self-reported leisure screen time (television and electronic game use) with indexes of adiposity in a population-based sample of British children. DESIGN: A cross-sectional study was conducted in 1862 UK children aged 9-10 y. PA and sedentary activity were measured by accelerometry, and indicators of adiposity were waist circumference, body mass index (BMI), and fat mass index calculated from bioimpedance measurements. Screen time was assessed by self-report. We examined the associations between PA subcomponents and adiposity by multilevel linear models adjusted for birth weight, maternal BMI, energy intake, and sleep duration. RESULTS: Objectively measured sedentary time was positively associated with waist circumference (P = 0.04) and fat mass index (P = 0.05), independent of age and sex. However, this association was attenuated after adjustment for MVPA and other covariates. VPA (all P < 0.0001), combined MVPA (all P < 0.01), and total activity (counts/min) (all P < 0.001) were all inversely associated with each of the adiposity indexes, independent of sedentary time and other important covariates. Associations were weaker for MPA: P = 0.05, 0.87, and 0.1 for waist circumference, BMI, and fat mass index, respectively. CONCLUSIONS: Time spent in VPA appears to be more strongly associated with adiposity than sedentary time. Interventions may therefore need to incorporate higher intensity-based activities to curb the growing obesity epidemic.

Su SW, Celler BG, Savkin AV, Nguyen HT, Cheng TM, Guo Y, Wang L. (Oct 2009). Transient and steady state estimation of human oxygen uptake based on noninvasive portable sensor measurements. Med Biol Eng Comput, 47(10), 1111-7

The main motivation of this study is to establish an ambulatory cardio-respiratory analysis system for the monitoring and evaluation of exercise and regular daily physical activity. We explored the estimation of oxygen uptake by using noninvasive portable sensors. These sensors are easy to use but may suffer from malfunctions under free living environments. A promising solution is to combine sensors with different measuring mechanisms to improve both reliability and accuracy of the estimation results. For this purpose, we selected a wireless heart rate sensor and a tri-axial accelerometer to form a complementary sensor platform. We analyzed the relationship between oxygen uptake measured by gas analysis and data collected from the simple portable sensors using multivariable nonlinear modeling approaches. It was observed that the resulting nonlinear multivariable model could not only achieve a better estimate compared with single input single output models, but also had greater potential to improve reliability.

Takano K, Tanno Y. (Dec 2009). Concreteness of thinking and self-focus. Conscious Cogn [Epub ahead of print]

The present study used the experience sampling method to detect fluctuations in thinking, such as self-focus or concreteness in daily life, and to examine their relationship with depressive symptoms and concurrent negative affect. Thirty-one undergraduates recorded their negative affect, ruminative self-focus, and concreteness of thinking eight times a day for 1week. Multilevel modeling showed that individuals with increasing levels of depression showed lower levels of concreteness in their daily thinking. Further analysis revealed a significant positive association between momentary ruminative self-focus and concurrent negative affect only with low concreteness of thinking. These results suggested that individuals with increasing levels of depression chronically process self-related information on an abstract level, which reflects a malfunction of their self-regulatory cycle and might serve to maintain or even exacerbate dysphoric moods.

Takeda R, Tadano S, Natorigawa A, Todoh M, Yoshinari S. (Nov 2009). Gait posture estimation using wearable acceleration and gyro sensors. J Biomech, 42(15), 2486-94

A method for gait analysis using wearable acceleration sensors and gyro sensors is proposed in this work. The volunteers wore sensor units that included a tri-axis acceleration sensor and three single axis gyro sensors. The angular velocity data measured by the gyro sensors were used to estimate the translational acceleration in the gait analysis. The translational acceleration was then subtracted from the acceleration sensor measurements to obtain the gravitational acceleration, giving the orientation of the lower limb segments. Segment orientation along with body measurements were used to obtain the positions of hip, knee, and ankle joints to create stick figure models of the volunteers. This method can measure the three-dimensional positions of joint centers of the hip, knee, and ankle during movement. Experiments were carried out on the normal gait of three healthy volunteers. As a result, the flexion-extension (F-E) and the adduction-abduction (A-A) joint angles of the hips and the flexion-extension (F-E) joint angles of the knees were calculated and compared with a camera motion capture system. The correlation coefficients were above 0.88 for the hip F-E, higher than 0.72 for the hip A-A, better than 0.92 for the knee F-E. A moving stick figure model of each volunteer was created to visually confirm the walking posture. Further, the knee and ankle joint trajectories in the horizontal plane showed that the left and right legs were bilaterally symmetric.

Tanaka C, Tanaka S. (Nov 2009). Daily physical activity in japanese preschool children evaluated by triaxial accelerometry: the relationship between period of engagement in moderate-to-vigorous physical activity and daily step counts. J Physiol Anthropol, 28(6), 283-8

The purpose of the present study was to evaluate moderate-to-vigorous physical activity using triaxial accelerometry in Japanese preschool children. The relationship between daily step counts as a convenient measure of physical activity and minutes of engagement in moderate-to-vigorous physical activity was also examined. Physical activity was assessed using a triaxial accelerometer (ActivTracer, GMS) and daily steps using a uniaxial accelerometer for 6 consecutive days, including weekdays and weekend days, in 157 four- to six-year-old Japanese children attending kindergarten or nursery school. Using triaxial and uniaxial accelerometers, nonlocomotive activities and step counts for young children can be evaluated, respectively. Average daily moderate-to-vigorous physical activity (physical activity ratio >or=3) and step counts were 102 (+/-32) min/day and 13,037 (+/-2,846) steps/day, respectively. A strong and significant correlation was observed between minutes of moderate-to-vigorous physical activity and step counts (r=0.832, p<0.001). The daily step counts corresponding to 60 min, 100 min, and 120 min of moderate-to-vigorous physical activity were 9,934, 12,893, and 14,373 steps/day, respectively. The correlation coefficient between minutes of higher intensity activities (physical activity ratio >or=4) and step counts was slightly lower (r=0.604, p<0.001). The daily step count corresponding to 30 min of the higher intensity activities was 14,768 steps/day. These results suggest that approximately 13,000 steps/day are required for preschool children to engage in more than 100 min of moderate-to-vigorous physical activity.

Trull TJ, Ebner-Priemer UW. (Dec 2009). Using experience sampling methods/ecological momentary assessment (ESM/EMA) in clinical assessment and clinical research: Introduction to the special section. Psychological Assessment, 21(4), 457-462

This article introduces the special section on experience sampling methods and ecological momentary assessment in clinical assessment. We review the conceptual basis for experience sampling methods (ESM; Csikszentmihalyi & Larson, 1987) and ecological momentary assessment (EMA; Stone & Shiffman, 1994). Next, we highlight several advantageous features of ESM/EMA as applied to psychological assessment and clinical research. We provide a brief overview of the articles in this special section, each of which focuses on 1 of the following major classes of psychological disorders: mood disorders and mood dysregulation (Ebner-Priemer & Trull, 2009), anxiety disorders (Alpers, 2009), substance use disorders (Shiffman, 2009), and psychosis (Oorschot, Kwapil, Delespaul, & Myin-Germeys, 2009). Finally, we discuss prospects, future challenges, and limitations of ESM/EMA.

Uswatte G, Hobbs Qadri L. (Nov 2009). A behavioral observation system for quantifying arm activity in daily life after stroke. Rehabilitation Psychology, 54(4), 398-403

Objective: Evaluate psychometric properties of the Functional Arm Activity Behavioral Observation System (FAABOS) for measuring hemiparetic arm use. Participants and Measures: All participants acquired their brain injury > 1 year prior to study entry; most had mild-to-moderate upper-extremity hemiparesis. In Study 1, 9 stroke survivors wore accelerometers and were videotaped for 15 min in the hospital or at home after they were asked to behave as usual. In Study 2, 1 traumatic brain injury and 8 stroke survivors wore accelerometers and were videotaped at home for 3 days with a motion-triggered camera. Observers independently rated 15-min segments of the Study 1 and 2 videotapes in 2-s blocks with a 4-step arm-activity coding scheme. Results: Interrater reliability was excellent; the mean Cohen’s κ in each study was ≥ .84. For data from both studies combined, validity was supported by a strong correlation between amount of hemiparetic arm functional activity, as determined by the observers, and the ratio of hemiparetic to other arm movement, as determined by accelerometry. Conclusion: FAABOS reliably and validly quantifies amount of spontaneous hemiparetic arm activity outside the laboratory.

Vahlkvist S, Pedersen S. (Nov 2009). Fitness, daily activity and body composition in children with newly diagnosed, untreated asthma. Allergy, 64(11), 1649-55

BACKGROUND: Information about how the asthma disease affects the life style and health in children is sparse. AIM: To measure fitness, daily physical activity and body composition in children with newly diagnosed, untreated asthma and healthy controls, and to assess the association between the level of asthma control and these parameters. METHODS: Daily physical activity measured using accelerometry, cardiovascular fitness and body composition (per cent fat, per cent lean tissue and bone mineral density) were measured in 57 children with newly diagnosed, untreated asthma and in 157 healthy age- and sex-matched controls. The level of asthma control was assessed by measurements of a variety of asthma outcomes. RESULTS: Children with asthma were less fit (35.1 vs 39.3 ml O(2)/min/kg) (P < 0.001), had a higher body per cent fat (22.8 vs 19.5%) (P < 0.01) and a higher frequency of overweight (24.6 vs 14.2%) (P < 0.05) than healthy controls. Per cent body fat correlated negativly to overall daily activity (P < 0.001) and to time spent in high or vigorous activity (P < 0.001). Fitness corrrelated positively to time spent in high and vigorous activity (P < 0.001). Within the asthma group, the level of asthma control, fitness and the time spent in vigorous activity correlated positively (P < 0.02). CONCLUSION: Children with untreated asthma are less fit and have a higher body per cent fat and frequency of obesity than their healthy peers. Uncontrolled asthma is associated with a reduced fitness and daytime spent in intensive activity. Overweight children are physically less active than normal weight children.

Vallée-Smejda S, Hahn M, Aubin N, Rosmus C. (Nov 2009). Recording practices and satisfaction of hemophiliac patients using two different data entry systems. Pers Soc Psychol Bull, 35(11),1440-5 Comput Inform Nurs, 27(6), 372-8

Record keeping is integral to home treatment for hemophilia. Identified problems with paper diaries include suboptimal compliance and questionable data validity and quality. The effects of an electronic data recording system, Advoy, on data quality, patient adherence, and satisfaction were examined. An exploratory approach was used to examine the sequential use of paper diaries and e-diaries by 38 patients. Data were obtained from paper records for the 6 months preceding the introduction of the electronic record and from the first 6 months of use of Advoy. Completion of mandatory and additional treatment details was also compared. More mandatory information (27.57%) was recorded with the e-diary. As well, the amount of completed additional fields nearly doubled (19.9%-36.5%). Patients tended to complete a greater variety of additional fields with the e-diary than with paper records. Finally, a higher percentage of survey respondents (29.4%) indicated that they were “very satisfied” with Advoy compared with paper records (6.7%). Most survey respondents (94.4%) had a previous experience with electronic programs. The use of the e-diary significantly improved patient adherence in recording mandatory treatment information; the increase in additional data provided by the patients was also found to be an added benefit of this technology.

Walther S, Koschorke P, Horn H, Strik W (Oct 2009). Objectively measured motor activity in schizophrenia challenges the validity of expert ratings. Psychiatry Research, 169(3), 187-190

Motor symptoms are frequent in schizophrenia and relevant to diagnosis. They are usually assessed by clinical observation and ratings based on psychometric scales. However, investigations with quantitative measurements are rare. To understand the relationship between the objective parameters of a quantitative motor activity measurement and the items related to motor symptoms of the Positive and Negative Syndrome Scale (PANSS), 55 schizophrenia patients were studied with 24-h continuous wrist actigraphy. Activity level, movement index, and mean duration of uninterrupted immobility periods were analyzed for wakeful periods. Actigraphic parameters were strongly inter-correlated. High PANSS negative syndrome subscale scores predicted low activity levels. Single PANSS items, such as suspiciousness, hallucinatory behavior, and emotional withdrawal, contributed largely to the variance in activity level and movement index. Age, gender, medication, and duration of illness had no significant impact on the actigraphic parameters. Interestingly, correlations between the specific motor symptoms of the PANSS and the actigraphic parameters were only found as a non-significant trend. We conclude that the objectively measured quantity of movement is related to the clinically assessed negative syndrome in schizophrenia. In contrast, PANSS items related to psychomotor behavior imprecisely reflect real quantitative motor activity.

Webber P, Abela JR, Auerbach R, Skitch S. (Oct 2009). Monitoring mobility in older adults using global positioning system (GPS) watches and accelerometers: a feasibility study. J Aging Phys Act, 17(4), 455-67

This exploratory study examined the feasibility of using Garmin global positioning system (GPS) watches and ActiGraph accelerometers to monitor walking and other aspects of community mobility in older adults. After accuracy at slow walking speeds was initially determined, 20 older adults (74.4 +/- 4.2 yr) wore the devices for 1 day. Steps, distances, and speeds (on foot and in vehicle) were determined. GPS data acquisition varied from 43 min to over 12 hr, with 55% of participants having more than 8 hr between initial and final data-collection points. When GPS data were acquired without interruptions, detailed mobility information was obtained regarding the timing, distances covered, and speeds reached during trips away from home. Although GPS and accelerometry technology offer promise for monitoring community mobility patterns, new GPS solutions are required that allow for data collection over an extended period of time between indoor and outdoor environments.

Whalen CK, Henker B, Ishikawa SS, Floro JN, Emmerson NA, Johnston JA, Swindle R. (Oct 2009). ADHD and anger contexts: Electronic diary mood reports from mothers and children. Journal of Pediatric Psychology, 34(9), 940-953

Objective: Using electronic diaries (eDiaries), this study examined temporal links between child and maternal anger, as well as positive mood and perceived stress, in children with attention–deficit/hyperactivity disorder (ADHD) versus comparison peers. Methods: Across 7 days, half-hourly eDiaries were completed independently by mothers and their 8–12-year-old children (51 receiving medication for ADHD and 58 comparison peers). Results: Cross-informant analyses revealed systematic patterns of negative maternal moods in relation to child anger in both groups along with evidence of slower recovery in the ADHD group. Analogously, for both groups, children’s anger reports increased and good-mood reports decreased in relation to maternal anger, whereas elevated stress in relation to maternal anger was restricted to children with ADHD. Conclusions: The findings indicate that a negative affective climate is more likely to persist in ADHD than in comparison families. They also affirm the utility of child as well as parent eDiary reports and suggest that children may be willing to report low positive mood when reluctant to report negative mood. The promise of incorporating real-time data on mood patterning into tailored treatments for children with ADHD and their families is discussed.

Yamazaki T, Gen-No H, Kamijo Y, Okazaki K, Masuki S, Nose H. (Dec 2009). A new device to estimate VO2 during incline walking by accelerometry and barometry. Med Sci Sports Exerc, 41(12), 2213-9

PURPOSE: To examine whether the biased estimation of oxygen consumption rate (VO2, mL x kg(-1) x min(-1)) by accelerometry during incline walking can be improved by the addition of altitude changes as measured by barometry. METHODS: We measured VO2 by respiratory gas analysis and vector magnitude (VM, G) from triaxial accelerations in 42 healthy people (mean +/- SD age = 63 +/- 7 yr) during graded walking on a treadmill while the incline was varied from -15% to +15%. They walked at subjectively slow, moderate, and fast speeds on level and uphill inclines and, in addition to these, at their fastest speed at 0% incline. They then walked at approximately 3, 4, and 5 km x h(-1) on downhill inclines for 3 min each. We determined a regression equation to estimate VO2 from VM and theoretical vertical upward (Hu, m x min(-1)) and downward speeds (Hd, m x min(-1)) for the last 1 min of each trial. To validate the precision of the equation, we measured VM and altitude changes with a portable device equipped with a triaxial accelerometer and a barometer in 11 of the 42 subjects walking on an outdoor hill and compared the estimated VO2 with the value simultaneously measured by respiratory gas analysis. RESULTS: VO2 above resting was estimated from VO2 = 0.044 VM + 1.365 Hu + 0.553 Hd (r = 0.93, P < 0.001) and the estimated V O2(y) was almost identical to the measured VO2(x) (y = 0.97x, r = 0.88, P < 0.001) with a mean difference of -0.20 +/- 3.47 (mean +/- SD) by Bland-Altman analysis in the range of 2.0-33.0 mL x kg(-1) x min(-1). CONCLUSIONS: VO2 during walking on various inclines can be precisely estimated by using the device equipped with a triaxial accelerometer and a barometer.

Yan IR, Poon CC, Zhang YT. (Dec 2009). Evaluation scale to assess the accuracy of cuff-less blood pressure measuring devices. Blood Press Monit, 14(6), 257-67

OBJECTIVE: The call for early detection of hypertension and cardiac events creates a heavy demand for devices that can be used for blood pressure (BP) monitoring at home and in ambulatory settings. An emerging type of BP monitors without an occluding cuff has drawn great attentions for this application because it is comfortable and capable of providing continuous readings. For the development the cuff-less devices, it is crucial for the clinicians and engineers to joint efforts in establishing an evaluation standard. METHODS: This study attempts to contribute to its initiation in two ways. First, a new distribution model for measurement differences between the test device and the reference was proposed. We verified the model using evaluation results from 40 devices, of which 80% of the American Association for the Advancement of Medical Instrumentation and British Hypertension Society reporting results were in agreement, as compared with 50%, if the original normal model was used. We further tested a cuff-less device on 85 patients for 999 datasets and found that the differences between the proposed distribution and that of the device were nonsignificant for systolic BP measurements (Kolmogorov-Smirnov = 0.036, P = 0.15). Second, some evaluation scales were studied for their capability to assess the accuracy of cuff-less devices. For mean absolute difference, a map was developed to relate it with the criteria of American Association for the Advancement of Medical Instrumentation, British Hypertension Society, and European Society of Hypertension protocols, on the basis of the proposed distribution model; for mean absolute percentage difference, it is prominent in evaluating devices that have measurement errors often increasing with BP, which is an issue has not been fully explored in existing standards. CONCLUSION: This study focused on the statistical aspect of establishing standard to assess the accuracy of cuff-less BP measuring devices. The results of our study on the validation reports of various cuff-based devices and an experimental study on a cuff-less device showed that the t4 distribution is better than the normal distribution in portraying the underlying error distribution of both kinds of devices. Moreover, based on both the theoretical and experimental studies, mean absolute difference or mean absolute percentage difference is recommended as continuous scale to assess the accuracy of cuff-less devices for their own distinctive advantages.

Zakeri IF, Adolph AL, Puyau MR, Vohra FA, Butte NF. (Jan 2010). Multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents. J Appl Physiol, 108(1), 128-36

Advanced mathematical models have the potential to capture the complex metabolic and physiological processes that result in heat production or energy expenditure (EE). Multivariate adaptive regression splines (MARS) is a nonparametric method that estimates complex nonlinear relationships by a series of spline functions of the independent predictors. The specific aim of this study is to construct MARS models based on heart rate (HR) and accelerometer counts (AC) to accurately predict EE, and hence 24-h total EE (TEE), in children and adolescents. Secondarily, MARS models will be developed to predict awake EE, sleep EE, and activity EE also from HR and AC. MARS models were developed in 109 and validated in 61 normal-weight and overweight children (ages 5-18 yr) against the criterion method of 24-h room respiration calorimetry. Actiheart monitor was used to measure HR and AC. MARS models were based on linear combinations of 23-28 basis functions that use subject characteristics (age, sex, weight, height, minimal HR, and sitting HR), HR and AC, 1- and 2-min lag and lead values of HR and AC, and appropriate interaction terms. For the 24-h, awake, sleep, and activity EE models, mean percent errors were -2.5 +/- 7.5, -2.6 +/- 7.8, -0.3 +/- 8.9, and -11.9 +/- 17.9%, and root mean square error values were 168, 138, 40, and 122 kcal, respectively, in the validation cohort. Bland-Altman plots indicated that the predicted values were in good agreement with the observed TEE, and that there was no bias with increasing TEE. Prediction errors for 24-h TEE were not statistically associated with age, sex, weight, height, or body mass index. MARS models developed for the prediction of EE from HR monitoring and accelerometry were demonstrated to be valid in an independent cohort of children and adolescents, but require further validation in independent, free-living populations.

Zhuo S, Wen W, Li-Yuan M, Shu-Yu W, Yi-Xin W. (Dec 2009). Home blood pressure measurement in prehypertension and untreated hypertension: comparison with ambulatory blood pressure monitoring and office blood pressure. Blood Press Monit, 14(6), 245-50

OBJECTIVES: (i) To explore blood pressure (BP) baseline characteristics in prehypertension (PH) and untreated essential hypertension (HT), and (ii) to evaluate whether simple home blood pressure (HBP) measurement can provide more reliable BP information than office blood pressure (OBP) in PH and untreated essential HT, and (iii) to investigate whether HBP measurement can also satisfactorily screen out masked hypertension (MH) and white-coat hypertension (WCH) by comparing with ambulatory blood pressure (ABP) monitoring. METHODS: We recruited 122 Beijing community volunteers. According to OBP measurement, they were divided into three groups, including PH group (n=51), stage 1 HT group (HT-1, n=51) and stage 2 HT group (HT-2, n=20). We calculated average OBP, HBP, and ABP, detection rate of MH, WCH, and nondipper status percentage in each group. RESULTS: Nondipper status percentage of PH, HT-1, and HT-2 was 54.9, 45.1, and 75%, respectively. Except for diastolic blood pressure difference between HBP and ABP, the others did not reach statistical significance. ABP correlated more strongly with HBP than OBP. Detection rate of MH in PH participants by HBP and ABP was 49.0 and 52.9% (P=0.56), respectively, and MH diagnostic agreement between ABP and HBP was moderate (kappa=0.53, 95% confidence interval: 0.30-0.76). Detection rate of WCH in stage 1 HT participants by HBP and ABP was 9.8 and 11.8% (P=0. 65), respectively, and WCH diagnostic agreement between ABP and HBP was moderate (kappa=0.49, 95% confidence interval: 0.10-0.87). CONCLUSION: Nondipper status percentage was higher in PH and untreated HT, and detection rate of MH in PH participants was also higher. The simple HBP measurement can provide more reliable and actual BP information and may be a feasibility of screening out MH and WCH for the clinical practice.

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