Society for Ambulatory Assessment

Fourth quarter 2006 (October to December)

Allen F.R., Ambikairajah E., Lovell N.H. & Celler B.G. (Oct 2006). Classification of a known sequence of motions and postures from accelerometry data using adapted Gaussian mixture models. Physiol Meas, 27(10):935-51.

Accelerometry shows promise in providing an inexpensive but effective means of long-term ambulatory monitoring of elderly patients. The accurate classification of everyday movements should allow such a monitoring system to exhibit greater ‘intelligence’, improving its ability to detect and predict falls by forming a more specific picture of the activities of a person and thereby allowing more accurate tracking of the health parameters associated with those activities. With this in mind, this study aims to develop more robust and effective methods for the classification of postures and motions from data obtained using a single, waist-mounted, triaxial accelerometer; in particular, aiming to improve the flexibility and generality of the monitoring system, making it better able to detect and identify short-duration movements and more adaptable to a specific person or device. Two movement classification methods were investigated: a rule-based Heuristic system and a Gaussian mixture model (GMM)-based system. A novel time-domain feature extraction method is proposed for the GMM system to allow better detection of short-duration movements. A method for adapting the GMMs to compensate for the problem of limited user-specific training data is also proposed and investigated. Classification performance was considered in relation to data gathered in an unsupervised, directed routine conducted in a three-month field trial involving six elderly subjects. The GMM system was found to achieve a mean accuracy of 91.3%, distinguishing between three postures (sitting, standing and lying) and five movements (sit-to-stand, stand-to-sit, lie-to-stand, stand-to-lie and walking), compared to 71.1% achieved by the Heuristic system. The adaptation method was found to offer a mean accuracy of 92.2%; a relative improvement of 20.2% over tests without subject-specific data and 4.5% over tests using only a limited amount of subject-specific data. While limited to a restricted subset of possible motions and postures, these results provide a significant step in the search for a more robust and accurate ambulatory classification system.

Antoni, M.H., Lechner, S.C. & Kazi, A. (Dec 2006). How Stress Management Improves Quality of Life After Treatment for Breast Cancer. Journal of Consulting and Clinical Psychology, Vol 74(6):1143-1152.

The range of effects of psychosocial interventions on quality of life among women with breast cancer remains uncertain. Furthermore, it is unclear which components of multimodal interventions account for such effects. To address these issues, the authors tested a 10-week group cognitive-behavioral stress management intervention among 199 women newly treated for nonmetastatic breast cancer, following them for 1 year after recruitment. The intervention reduced reports of social disruption and increased emotional well-being, positive states of mind, benefit finding, positive lifestyle change, and positive affect for up to 12 months (indeed, some effects strengthened over time). With respect to mechanisms tested, the intervention increased confidence in being able to relax at will. There was also evidence that effects of the intervention on the various outcomes examined were mediated by change in confidence about being able to relax. Thus, this intervention had beneficial effects on diverse aspects of quality of life after treatment for breast cancer, which appear linked to a specific stress management skill taught in the intervention.

Badr, H., Basen-Engquist, K, & Taylor, C.L.C. (Oct 2006). Mood States Associated with Transitory Physical Symptoms Among Breast and Ovarian Cancer Survivors. Journal of Behavioral Medicine, Vol 29(5):461-475.

This study used electronic diaries to examine patterns of mood and physical symptoms within and across days in two independent samples of cancer patients. Twenty-three breast cancer survivors (post-treatment) and 33 ovarian cancer survivors (on chemotherapy) recorded mood and physical symptoms 4 times daily for 7 consecutive days. A series of repeated-measures multilevel models using SAS Proc Mixed were calculated to estimate the degree to which physical symptoms (e.g., pain, fatigue, and nausea) were associated with participants’ moods. Across days, mood vectors with a pleasantness component (i.e., happy-sad and calm-anxious) and mood vectors with an arousal component (i.e., active-passive and peppy-tired) were significantly associated with physical symptom severity. Specifically, breast cancer survivors with greater fatigue and pain reported more negative moods (η² < 0.33). Ovarian cancer survivors with greater fatigue (η² < 0.35), pain (η² < 0.04), and nausea (η² < 0.04) also reported more negative moods. Diurnal analyses showed that happy-sad (η² < 0.16), active-passive (η² < 0.27), and peppy-tired moods (η² < 0.33) were significantly negatively associated with fatigue at each of the four daily assessment times in both samples. Although correlational, our findings are consistent with previous studies suggesting that variations in both pleasant and aroused mood covary with changes in real-time physical symptom reports.

Birnbaum, G.E., Reis, H.T. & Mikulincer, M. (Nov 2006). When Sex Is More Than Just Sex: Attachment Orientations, Sexual Experience, and Relationship Quality. Journal of Personality and Social Psychology, Vol 91(5):929-943.

The authors explored the contribution of individual differences in attachment orientations to the experience of sexual intercourse and its association with relationship quality. In Study 1, 500 participants completed self-report scales of attachment orientations and sexual experience. The findings indicated that whereas attachment anxiety was associated with an ambivalent construal of sexual experience, attachment avoidance was associated with more aversive sexual feelings and cognitions. In Study 2, 41 couples reported on their attachment orientations and provided daily diary measures of sexual experiences and relationship interactions for a period of 42 days. Results showed that attachment anxiety amplified the effects of positive and negative sexual experiences on relationship interactions. In contrast, attachment avoidance inhibited the positive relational effect of having sex and the detrimental relational effects of negative sexual interactions. The authors discuss the possibility that attachment orientations are associated with different sex-related strategies and goals within romantic relationships.

Campbell, T.S., Lavoie, K.L. & Bacon, S.L. (Oct 2006). Asthma self-efficacy, high frequency heart rate variability, and airflow obstruction during negative affect in daily life. International Journal of Psychophysiology, Vol 62(1):109-114.

Background: Emotional stress has been considered an important asthma trigger for years, though the mechanisms by which stress may exacerbate asthma remain poorly understood. The stress-asthma morbidity association could occur through cognitive-behavioral pathways, such as decreased asthma self-efficacy and disorganized self-care, or through the more direct physiological effects of stress on autonomic (parasympathetic) nervous system activity. No study has examined how these two mechanisms may interact to contribute to greater airflow obstruction during emotional stress in daily life. This study investigated associations between peak expiratory flow rate (PEFR) and high frequency heart rate variability (HFHRV) during periods of negative affect and physical activity in daily life in patients with higher versus lower asthma self-efficacy scores. Methods: Fifty-three patients with mild to moderate asthma completed the Asthma Self-Efficacy Scale (ASES) and underwent a 15 h ambulatory assessment of daytime HFHRV and PEFR, while completing self-report diaries of their physical activities and affect. Results: In patients with lower asthma self-efficacy scores, increased levels of negative affect during daily life were associated with higher levels of HFHRV and decreased PEFR relative to patients with higher asthma self-efficacy scores. Increased levels of physical activity were associated with decreased levels of HFHRV irrespective of asthma self-efficacy scores. Conclusions: Findings suggest that lower asthma self-efficacy may be associated with increased parasympathetic activity and airflow obstruction during periods of negative affect during daily life.

Ebner-Priemer, U.W., Kuo, J & Welch, S.S. (Oct 2006). A Valence-Dependent Group-Specific Recall Bias of Retrospective Self-Reports: A Study of Borderline Personality Disorder In Everyday Life. Journal of Nervous and Mental Disease, Vol 194(10):774-779.

Recall is an active reconstruction process likely to distort past experiences. This distortion, known as recall bias, seems to manifest itself differently in sick and healthy people. A recall bias has been documented in several disorders, but never investigated in borderline personality disorder (BPD). To determine recall bias in BPD, we assessed momentary and retrospective ratings of specific emotions in 50 patients with BPD and 50 healthy controls (HCs), using the methodology of 24-hour ambulatory monitoring. Our data reveal a group-specific valence-dependent recall bias of retrospective self-report, indicated by a different overall recall pattern in HCs and BPD. BPD patients show an overall negative recall pattern, whereas HCs show a positive recall pattern. A traditional questionnaire approach does not distinguish between symptoms of the disorder and recall bias, although the pathological mechanisms underlying them as well as the appropriate treatment strategies may be different.

Felicio J.S., Pacheco J.T., Ferreira S.R., Plavnik F., Moises V.A., Kohlmann O.J., Ribeiro A.B. & Zanella M.T. (2006). Hyperglycemia and nocturnal systolic blood pressure are associated with left ventricular hypertrophy and diastolic dysfunction in hypertensive diabetic patients. Cardiovascular Diabetology, 5:19.

BACKGROUND: The aim of this study was to determine if hypertensive type 2 diabetic patients, when compared to patients with essential hypertension have an increased left ventricular mass index (LVMI) and a worse diastolic function, and if this fact would be related to 24-h pressoric levels changes. METHODS: Ninety-one hypertensive patients with type 2 diabetes mellitus (DM) (group-1 [G1]), 59 essential hypertensive patients (group-2 [G2]) and 26 healthy controls (group-3 [G3]) were submitted to 24-h Ambulatory Blood Pressure Monitoring (ABPM) and echocardiography (ECHO) with Doppler. We calculated an average of fasting blood glucose (AFBG) values of G1 from the previous 4.2 years and a glycemic control index (GCI) (percentual of FBG above 200 mg/dl). RESULTS: G1 and G2 did not differ on average of diurnal systolic and diastolic BP. However, G1 presented worse diastolic function and a higher average of nocturnal systolic BP (NSBP) and LVMI (NSBP = 132 +/- 18 vs 124 +/- 14 mmHg; P < 0.05 and LVMI = 103 +/- 27 vs 89 +/- 17 g/m2; P < 0.05, respectively). In G1, LVMI correlated with NSBP (r = 0.37; P < 0.001) and GCI (r = 0.29; P < 0.05) while NSBP correlated with GCI (r = 0.27; P < 0.05) and AFBG (r = 0.30; P < 0.01). When G1 was divided in tertiles according to NSBP, the subgroup with NSBP> or =140 mmHg showed a higher risk of LVH. Diabetics with NSBP> or =140 mmHg and AFBG>165 mg/dl showed an additional risk of LVH (P < 0.05; odds ratio = 11). In multivariate regression, both GCI and NSBP were independent predictors of LVMI in G1. CONCLUSION: This study suggests that hyperglycemia and higher NSBP levels should be responsible for an increased prevalence of LVH in hypertensive patients with Type 2 DM.

Ferguson, S.G., Shiffman, S & Gwaltney, C.J. (Dec 2006). Does Reducing Withdrawal Severity Mediate Nicotine Patch Efficacy? A Randomized Clinical Trial. Journal of Consulting and Clinical Psychology, Vol 74(6):1153-1161.

Nicotine replacement therapy (NRT) repeatedly has been shown to improve smoking treatment outcome. The major mechanism posited for this improvement in outcome is that NRT reduces nicotine craving and withdrawal. The authors tested this hypothesized mechanism of action using real-time data on craving and withdrawal, collected by ecological momentary assessments administered on a palm-top computer. Smokers (N = 324) were randomized to receive either active high-dose (35 mg) 24-hr patches or placebo. Increases in positive affect and decreases in craving, negative affect, and attention disturbance severity were related to lower risk of lapsing. Although NRT treatment did significantly decrease withdrawal and craving severity, these reductions only partially accounted for NRT’s impact on time to first lapse: The results from a mediation analysis showed that the hazard ratio for NRT, when controlling for withdrawal and craving severity, was only a third to a half lower than the uncontrolled hazard ratio for NRT alone. This suggests that other mechanisms for the effectiveness of NRT need to be examined.

Fialho G., Cavichio L., Povoa R. & Pimenta J. (Oct 2006). Effects of 24-h shift work in the emergency room on ambulatory blood pressure monitoring values of medical residents. Am J Hypertens, 19(10):1005-9.

BACKGROUND: Medical residency is marked by long work hours and shift work. The acute effects of these factors on the blood pressure (BP) of medical residents have not been adequately evaluated. METHODS: A total of 61 medical residents underwent to ambulatory blood pressure monitoring (ABPM) during a 24-h shift work in the emergency room (ER) and during a common working day. RESULTS: Both mean 24-h systolic and diastolic BP (DBP) and mean diastolic BP readings during sleep were higher during the 24-h shift work in the ER than during common working day (117 v 113 mm Hg, P < .05; 73 v 69 mm Hg, P < .05; and 61 v 58 mm Hg, P < .05, respectively). Abnormally high mean BP readings were more frequent during the 24-h shift work in the ER than in common working day (19 v 8, P < .05). Pressure load, nocturnal BP fall and pulse pressure values were similar in these two different working situations. CONCLUSION: Working in the ER on a 24-h shift leads to abnormal BP behavior in medical residents, thus suggesting that this type of work may be a risk factor for cardiovascular disease.

Giansanti D. (Oct 2006). Does centripetal acceleration affect trunk flexion monitoring by means of accelerometers?. Physiol Meas, 27(10):999-1008.

Micro electro-mechanical and NANO technologies are sensibly reducing circuit and geometrical errors in accelerometer sensors. These sensors are often used as portable inclinometer sensors for trunk flexion monitoring in clinical applications. In this case, the rotating trunk generates centripetal acceleration, an error source that technological efforts cannot eliminate. This study analysed the effect of this source for typical human monitoring conditions by simulations and clinical validation using a wearable device with rate gyroscopes and accelerometers (Giansanti and Maccioni 2005 Physiol. Meas. 26 689-705). Results showed that this error source did not affect long-term monitoring applications (Mathie et al 2004 Physiol. Meas. 25 R1-R20) but in the short-term monitoring caused a mean angular error equal to 0.96 degrees for the most critical single-task application represented by the sit-to-stand.

Grossman E., Laudon M., Yalcin R., Zengil H., Peleg E., Sharabi Y., Kamari Y., Shen-Orr Z. & Zisapel N. (Oct 2006). Melatonin reduces night blood pressure in patients with nocturnal hypertension. Am J Med, 119(10):898-902.

PURPOSE: Nocturnal hypertension is associated with a high risk of morbidity and mortality. A blunted nocturnal surge in melatonin excretion has been described in nondipping hypertensive patients. We therefore studied the potency of melatonin to reduce nighttime blood pressure (BP) in treated hypertensive patients with nocturnal hypertension. PATIENTS AND METHODS: Thirty-eight treated hypertensive patients (22 males, mean age 64+/-11 years) with confirmed nocturnal hypertension (mean nighttime systolic BP >125 mm Hg), according to repeated 24-hour ambulatory blood pressure monitoring (ABPM), were randomized in a double-blind fashion to receive either controlled release (CR)-melatonin 2 mg or placebo 2 hours before bedtime for 4 weeks. A 24-hour ABPM was then performed. RESULTS: Melatonin treatment reduced nocturnal systolic BP significantly from 136+/-9 to 130+/-10 mm Hg (P=.011), and diastolic BP from 72+/-11 to 69+/-9 mm Hg (P=.002), whereas placebo had no effect on nocturnal BP. The reduction in nocturnal systolic BP was significantly greater with melatonin than with placebo (P=.01), and was most prominent between 2:00 AM and 5:00 AM (P=.002). CONCLUSIONS: Evening CR-melatonin 2 mg treatment for 4 weeks significantly reduced nocturnal systolic BP in patients with nocturnal hypertension. Thus, an addition of melatonin 2 mg at night to stable antihypertensive treatment may improve nocturnal BP control in treated patients with nocturnal hypertension.

Hardway, C & Fuligni, A.J. (Nov 2006). Dimensions of Family Connectedness Among Adolescents with Mexican, Chinese, and European Backgrounds. Developmental Psychology, Vol 42(6):1246-1258.

Multiple dimensions of adolescents’ connectedness with their families were investigated among 489 9th-grade students (M = 14.86 years) from families with Mexican, Chinese, and European backgrounds. Participants reported on various aspects of their family relationships and completed diary checklists of daily behaviors for a 2-week period. Adolescents from European backgrounds reported levels of family identification and dyadic closeness with parents similar to or greater than those reported by their peers. For adolescents from Mexican and Chinese backgrounds, particularly those from immigrant families, family connectedness included a stronger emphasis on family obligation and assistance. The extent to which family demographic variables, including parental level of education and residence in a single-parent family, accounted for group differences was examined.

Head G.A., Reid C.M., Shiel L.M., Jennings G.L. & Lukoshkova E.V. (Oct 2006). Rate of morning increase in blood pressure is elevated in hypertensives. Am J Hypertens, 19(10):1010-7.

BACKGROUND: We applied a new logistic curve fitting procedure to ambulatory blood pressure (ABP) recordings to determine whether the rate of increase in systolic (SBP), mean (MBP) and diastolic blood pressure (DBP) and heart rate (HR) in the morning is related to the level of BP in subjects. METHODS: The rate of transition in the morning and evening period was determined using a six-parameter double-logistic equation applied to 528 ABP recordings from a cardiovascular risk assessment clinic. Based on daytime BP (MBP, SBP, or DBP), the upper quartile (UQ, n = 132) and lower quartile (LQ) were compared. RESULTS: Subjects in the UQ of daytime MBP were hypertensive and showed greater day-night differences compared to normotensive subjects in the LQ (29 +/- 1 mm Hg for MBP compared to 20 +/- 1 mm Hg). The rate of morning increase in SBP and DBP was 42% and 30% greater in UQ subjects compared to the LQ subjects (P < .05). The rates of evening decrease in all BPs were 69% to 84% greater in the subjects in the UQ. Similar results were obtained if subjects were divided according to daytime SBP or DBP. The rate of morning increase in MBP was correlated with daytime BP, but not night-time or 24 h MBP. CONCLUSIONS: The rate of morning increase in BP is greater in those subjects with the highest daytime BP. The exaggerated rate of morning increase in BP in this group, which were all hypertensive, may also be important for greater cardiovascular risk.

Hopper, J.W., Su, Z & Looby, A.R (Dec 2006). Incidence and patterns of polydrug use and craving for ecstasy in regular ecstasy users: An ecological momentary assessment study. Drug and Alcohol Dependence, Vol 85(3):221-235.

Background: Previous studies employing retrospective assessments methods found that regular ecstasy users frequently use alcohol, marihuana and other drugs in combination with ecstasy. Methods: Twenty-two participants (13 males, 9 females) wore a wrist actigraph/data recorder to record real-time drug use and ecstasy craving for 6 weeks. Rates of alcohol and drug use on ecstasy use versus non-use nights, and before, during, and after ecstasy use were analyzed with generalized estimation equations (GEE). Craving was modeled with GEE and linear mixed models. Results: Approximately 70% of ecstasy uses occurred on Friday or Saturday nights. No drug was significantly more likely to be used on ecstasy use nights than comparison Friday and Saturday nights. On nights ecstasy was used, in general across all drugs assessed, use was more likely before and during than after ecstasy intoxication, while alcohol use was also more likely before than during ecstasy intoxication. Though low overall, craving for ecstasy increased over 24 h before use and was higher on Friday nights of weeks ecstasy was used on weekends than weeks it was not used. Conclusions: Use of ecstasy on a particular night may not be associated with any greater likelihood of using any other intoxicating drug, and use of other drugs on nights involving ecstasy use may simply reflect a “natural history” of drug-use nights that begins with alcohol, progresses to more intoxicating drugs, and ends with little drug use. Confirmation of these findings awaits further advances in the application of ecological momentary assessment methodologies.

Hoppmann, C.A. & Klumb, P.L. (Nov/Dec 2006). Daily Goal Pursuits Predict Cortisol Secretion and Mood States in Employed Parents With Preschool Children. Psychosomatic Medicine, 68(6):887-894.

Objective: This study examined the relationship between the personal relevance of daily activities with respect to self-set work and family goals and affective and neuroendocrine stress reactions. Methods: A total of 53 dual-earner couples with preschool children participated in a 1-week interval-sampling study. At the beginning, participants reported their personal work and family goals. During the time-sampling phase, both partners reported the goal relevance of their daily activities, current mood, and provided saliva samples for cortisol estimation every 3 hours. Results: Hierarchical linear models show that the performance of goal-furthering activities is associated with more positive mood and decreased secretion of cortisol. The relationship between the goal relevance of daily activities and cortisol was partially mediated by affect quality. Conclusions: These findings speak to a person-centered approach in research on stress by showing that knowledge of individual goals is important for an understanding of affective and neuroendocrine stress reactions in employed parents with preschool children.

Inoue R., Ohkubo T., Kikuya M., Metoki H., Asayama K., Obara T., Hoshi H., Hashimoto J., Totsune K., Satoh H., Kondo Y. & Imai Y. (Nov 2006). Predicting stroke using 4 ambulatory blood pressure monitoring-derived blood pressure indices: the Ohasama Study. Hypertension, 48(5):877-82.

We investigated the association between stroke and blood pressure (BP) indices (systolic BP [SBP], diastolic BP [DBP], mean BP [MBP], and pulse pressure [PP]) determined by ambulatory BP monitoring. The predictive power for stroke of these indices was compared in the general Japanese population. We obtained ambulatory BP data in 1271 subjects (40% men) aged > or = 40 (mean: 61) years. During a mean follow-up of 11 years, 113 strokes were observed. The multivariate adjusted relative hazard and likelihood ratio for a 1-SD increase for each BP index was determined by Cox proportional hazard regression. Comparison of the likelihood ratio between Cox models including 2 indices and those including 1 index indicated that PP was significantly less informative than other indices (P<0.01 when adding MBP, SBP, or DBP to the PP model; P>0.09 when adding PP to the model including another index). However, after removing age from covariates, PP became more informative than DBP and MBP (P<0.0001 when adding PP to the MBP or DBP model, whereas SBP was more informative than PP even after removing age; P<0.05 when adding SBP to the PP model). In conclusion, PP was the weakest predictor of stroke. Exclusion of age from covariates increased the predictive power of PP, suggesting that the stroke risk associated with PP reflected the risk of aging per se.

Kikuchi, H., Yoshiuchi, K., Miyasaka, N., Ohashi, K., Yamamoto, Y., Kumano, H., Kuboki, T. & Akabayashi, A. (Nov 2006). Reliability of recalled self-report on headache intensity: investigation using ecological momentary assessment technique. Cephalalgia, 26(11):1335-1343.

Recalled evaluation of headache intensity is often affected by several factors. Recently, computerized ecological momentary assessment (EMA) has been developed to avoid such problems as recall bias. Here, we compared recalled headache intensity with momentary headache intensity using EMA in tension-type headache (TTH). Forty patients with TTH wore watch-type computers for 1 week to record momentary headache intensity and also rated their headache intensities by recall. We calculated intraclass correlation coefficients between recalled headache intensity and indices from EMA recordings in the whole study population and in two subgroups divided by variability of momentary headache intensity. The results showed that consistency and agreement of momentary and recalled headache intensity were low, and this was especially marked in the subjects whose headache varied widely. These observations suggested that variability of headache intensity may affect recall of headache intensity and this should be taken into consideration in both clinical and research settings.

Klumb, P, Hoppmann, C. & Staats, M. (Nov 2006). Division of Labor in German Dual-Earner Families: Testing Equity Theoretical Hypotheses. Journal of Marriage and Family, Vol 68(4):870-882.

On the basis of 52 German dual-earner couples with at least 1 child younger than 5 years, we tested the effects of an unequal division of labor on relationship satisfaction. We analyzed diary reports of time allocated to productive activities according to the actor-partner-interdependence model. Hierarchical linear models showed that rather than individual time allocated to household work, the absolute difference in partners’ contribution to productive activities influenced relationship satisfaction. This reduction in satisfaction disappeared after accounting for perceived social appreciation of individual contributions. Models with gender-specific slopes showed the effect of input and output to be different for women and men. The findings indicate that a relative equity model best explains the effects of an unequal division of labor.

Klumb, P. L., Hoppmann, C. A. & Staats, M. (2006). Work hours affect spouse’s cortisol secretion-For better and for worse. Psychosomatic Medicine, 68, 742-746.

Objective: In a sample of 52 German dual-earner couples with at least one child under age 5, we examined the bodily costs and benefits of the amount of time each spouse spent on productive activities. Methods: Diary reports of time allocated to formal and informal work activities were analyzed according to the Actor-Partner Interdependence model. Results: Hierarchical linear models showed that each hour an individual allocated to market, as well as household work, increased his or her total cortisol concentration (by 192 and 134 nmol/l, respectively). Unexpectedly, the time the spouse allocated to paid work also raised an individual’s total cortisol concentration (by 64 nmol/l). In line with our expectations, there was a tendency for the time the spouse allocated to household work to decrease the individual’s cortisol concentration (by 81 nmol/l). Conclusions: This study contributes to the body of evidence on the complex nature of social relationships and complements the literature on specific working conditions and couples’ well-being. Key words: cortisol secretion, marriage, partner effect, quantitative workload.

Macfarlane D.J., Lee C.C., Ho E.Y., Chan K.L. & Chan D. (Nov 2006). Convergent validity of six methods to assess physical activity in daily life. J Appl Physiol, 101(5):1328-34.

The purpose was to examine the agreement (convergent validity) between six common measures of habitual physical activity to estimate durations of light, moderate, vigorous, and total activity in a range of free-living individuals. Over 7 consecutive days, 49 ethnic Chinese (30 men, 19 women), aged 15-55 yr, wore a Polar heart rate monitor, a uniaxial MTI, and triaxial Tritrac accelerometer, plus a Yamax pedometer for > or = 600 min/day. They also completed a daily physical activity log and on day 8 a Chinese version of the 7-day International Physical Activity Questionnaire. At each level of activity, there was good agreement between the two questionnaire-derived instruments and the two accelerometry-derived instruments, but wide variation across different instruments, with two- to fourfold differences in mean durations often seen. The heart rate monitor overestimated light activity and underestimated moderate activity compared with all other measures. Spearman correlation coefficients were low to moderate (0.2-0.5) across most measures of activity, with the pedometer showing correlations with total activity that were often superior to the other movement sensors. We conclude that, with the use of commonly accepted cut points for defining light, moderate, vigorous, and total activity, little convergent validity across the instruments was evident, suggesting these measures are sampling different levels of habitual physical activity and care is needed when comparing their results. To provide a more stable comparison of activity among different people, across studies, or against accepted physical activity promotion guidelines, further work is needed to fine tune the different cut points across a range of common activity monitors to provide more consistent results during free-living conditions.

Nyan M.N., Tay F.E., Tan A.W. & Seah K.H. (2006 Oct). Distinguishing fall activities from normal activities by angular rate characteristics and high-speed camera characterization. Med Eng Phys, 28(8):842-9.

Distinguishing sideways and backward falls from normal activities of daily living using angular rate sensors (gyroscopes) was explored in this paper. Gyroscopes were secured on a shirt at the positions of sternum (S), front of the waist (FW) and right underarm (RU) to measure angular rate in lateral and sagittal planes of the body during falls and normal activities. Moreover, the motions of the fall incidents were captured by a high-speed camera at a frame rate of 250 frames per second (fps) to study the body configuration during fall. The high-speed camera and the sensor data capture system were activated simultaneously to synchronize the picture frame of high-speed camera and the sensor data. The threshold level for each sensor was set to distinguish fall activities from normal activities. Lead time of fall activities (time after threshold value is surpassed to the time when the hip hits the ground) and relative angle of body configuration (angle beta between the vertical line and the line from the center point of the foot or the center point between the two legs to that of the waist) at the threshold level were studied. For sideways falls, lead times of sensors at positions FW and S were about 200-220ms and 135-182ms, respectively. The lead time of the slippery backward fall (about 98ms) from the sensor at position RU was shorter than that of the sideways falls from the sensors at positions FW and S. The relative angle of body configuration at threshold level for sideways and backward falls were about 40-43 degrees for the sensor at position FW, about 43-52 degrees for the sensor at position S and about 54 degrees for the sensor at position RU, respectively. This is the first study that investigates fall dynamics in detection of fall before the person hits the ground using angular rate sensors (gyroscopes).

Piferi, R L. & Lawler, K.A. (Nov 2006). Social support and ambulatory blood pressure: An examination of both receiving and giving. International Journal of Psychophysiology, Vol 62(2):328-336.

The relationship between the social network and physical health has been studied extensively and it has consistently been shown that individuals live longer, have fewer physical symptoms of illness, and have lower blood pressure when they are a member of a social network than when they are isolated. Much of the research has focused on the benefits of receiving social support from the network and the effects of giving to others within the network have been neglected. The goal of the present research was to systematically investigate the relationship between giving and ambulatory blood pressure. Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate were recorded every 30 min during the day and every 60 min at night during a 24-h period. Linear mixed models analyses revealed that lower systolic and diastolic blood pressure and mean arterial pressure were related to giving social support. Furthermore, correlational analyses revealed that participants with a higher tendency to give social support reported greater received social support, greater self-efficacy, greater self-esteem, less depression, and less stress than participants with a lower tendency to give social support to others. Structural equation modeling was also used to test a proposed model that giving and receiving social support represent separate pathways predicting blood pressure and health. From this study, it appears that giving social support may represent a unique construct from receiving social support and may exert a unique effect on health.

Prill T. & Fahrenberg J. (Oct 2006). Simultaneous assessment of posture and limb movements (e.g., periodic leg movements) with calibrated multiple accelerometry. Physiol Meas, 27(10):N47-53.

This study describes new applications for the method of calibrated multiple accelerometry, which detects posture and distinct motion patterns, and limb movements continuously. The aim of our study was to evaluate this assessment technique in terms of its suitability for exploring the relationships between pathological limb movement activity (e.g., periodic leg movements) and posture. The new method proved to be appropriate for the simultaneous assessment of pathological leg jerks and posture and provided a means to revealing possible relations. Generally, our study demonstrates the application of this (ambulatory) assessment technique in the field of sleep and neurological disorders.

Reilly J.J., Kelly L., Montgomery C., Williamson A., Fisher A., McColl J.H., Lo Conte R., Paton J.Y. & Grant S. (Nov 2006). Physical activity to prevent obesity in young children: cluster randomised controlled trial. BMJ, 18;333(7577):1041.

OBJECTIVE: To assess whether a physical activity intervention reduces body mass index in young children. DESIGN: Cluster randomised controlled single blinded trial over 12 months. SETTING: Thirty six nurseries in Glasgow, Scotland. PARTICIPANTS: 545 children in their preschool year, mean age 4.2 years (SD 0.2) at baseline. INTERVENTION: Enhanced physical activity programme in nursery (three 30 minute sessions a week over 24 weeks) plus home based health education aimed at increasing physical activity through play and reducing sedentary behaviour. MAIN OUTCOME MEASURE: Body mass index, expressed as a standard deviation score relative to UK 1990 reference data. Secondary measures were objectively measured physical activity and sedentary behaviour; fundamental movement skills; and evaluation of the process. RESULTS: Group allocation had no significant effect on the primary outcome measure at six and 12 months or on measures of physical activity and sedentary behaviour by accelerometry. Children in the intervention group had significantly higher performance in movement skills tests than control children at six month follow-up (P=0.0027; 95% confidence interval 0.3 to 1.3) after adjustment for sex and baseline performance. CONCLUSIONS: Physical activity can significantly improve motor skills but did not reduce body mass index in young children in this trial. TRIAL REGISTRATION: Current Controlled Trials ISRCTN36363490.

Roelofs, J., Peters, M.L., Patijn, J., Schouten, E.G.W. & Vlaeyen, J.W.S. (Nov 2006). An electronic diary assessment of the effects of distraction and attentional focusing on pain intensity in chronic low back pain patients. British Journal of Health Psychology, 11(4):595-606.

Objective. The present study examined the effects of a manipulation of attention to pain (i.e. attentional focusing vs. distraction) on pain intensity in daily life of patients with chronic low back pain. It was hypothesized that attentional focusing would lead to decreased pain intensity in high pain fearful individuals, whereas distraction from pain would be associated with decreased pain intensity in low pain fearful individuals. Design. An experience sampling methodology was used to examine the effects of a manipulation of attention to pain on pain intensity in daily life of pain patients. Methods. A total number of 38 patients with chronic low back pain participated in this study and carried a palmtop computer for 2 weeks. During this period, patients were ‘beeped’ 8 times a day to complete diary questions. On certain days, instructions to either attend to or distract from pain were given. Results. Multi-level analyses showed that attentional focusing was not associated with decreased pain intensity in high pain fearful individuals and that distraction did not lead to decreased pain intensity in low pain fearful individuals. The manipulations in isolation neither influenced pain intensity. The manipulation check was generally weak. Conclusion. A manipulation of attention to pain in daily life of patients with chronic low back pain proved difficult to accomplish. As the manipulation check was generally unsuccessful, no clear inferences about the underlying theory can be made. Future research within the field of pain treatments (e.g. in vivo exposure) might benefit greatly from electronic diary assessments studies.

Shiffman, S., Patten, C., Gwaltney, C., Paty, J., Gnys, M., Kassel, J., Hickcox, M., Waters, A. & Balabanis, M. (Dec 2006). Natural history of nicotine withdrawal. Addiction, 101(12):1822-1832.

Aims: To examine the natural history of nicotine withdrawal and individual differences associated with withdrawal duration and severity. Design and Setting: Prospective study of withdrawal symptoms among smokers who quit for at least 24 hours. Participants used Ecological Momentary Assessment to monitor symptoms in their natural environment using an Electronic Diary (ED). Participants: A total of 214 cigarette smokers (59% female, 92% Caucasian). Intervention: All participants received a clinic-based, behavioral, group cessation intervention. Severity and duration of withdrawal was not addressed explicitly in treatment. Measurements: Participants were ‘beeped’ by the ED approximately five times/day to complete affect assessments (negative affect, arousal, attention disturbance, restlessness), and daily assessments of sleep disturbance (at waking) and of cognitive performance (each evening) for a week prior to quitting and for up to 21 days after quitting. Withdrawal was considered resolved when withdrawal scores returned to baseline levels for at least 2 consecutive days. Findings: All symptoms returned to baseline levels within 10 days of quitting. All variables except arousal and sleep disturbance showed change over time. No robust predictors of individual differences in withdrawal responses emerged. Conclusions: The time-course of withdrawal may be shorter than previously reported. The natural history of nicotine withdrawal may have implications for theories of withdrawal and smoking relapse and for smoking cessation treatment.

Tryon W.W., Tryon G.S. & Kazlausky T. (Oct 2006). Reducing Hyperactivity with a Feedback Actigraph: Initial Findings. Clinical Child Psychology and Psychiatry, 11(4):607-617.

Schulman and colleagues demonstrated that classroom activity level can be reduced in hyperactive boys using activity-level feedback and positive reinforcement. This article reports preliminary results using a device that combines modern beeper and actigraphy technology for the purpose of measuring, monitoring, and modifying motor excess in children with confirmed diagnoses of Attention Deficit Hyperactivity Disorder (ADHD). Nine boys ranging in age from 8 to 9 years with the ADHD Combined Type wore prototype BuzzBee® feedback actigraphs during school periods and were reinforced for activity-level reductions in the context of a simple pre/post research design. The findings indicated that 7 of the 9 boys reduced their activity level from 20 to 47% of baseline levels while the activity levels of the two remaining boys increased from 2 to 7% of baseline levels. These changes were statistically significant and constitute a large effect.

Uswatte G., Taub E., Morris D., Light K. & Thompson P.A. (Oct 2006). The Motor Activity Log-28: assessing daily use of the hemiparetic arm after stroke. Neurology, 10;67(7):1189-94.

BACKGROUND: Data from monkeys with deafferented forelimbs and humans after stroke indicate that tests of the motor capacity of impaired extremities can overestimate their spontaneous use. Before the Motor Activity Log (MAL) was developed, no instruments assessed spontaneous use of a hemiparetic arm outside the treatment setting. OBJECTIVE: To study the MAL’s reliability and validity for assessing real-world quality of movement (QOM scale) and amount of use (AOU scale) of the hemiparetic arm in stroke survivors. METHODS: Participants in a multisite clinical trial completed a 30-item MAL before and after treatment (n = 106) or an equivalent no-treatment period (n = 116). Participants also completed the Stroke Impact Scale (SIS) and wore accelerometers that monitored arm movement for three consecutive days outside the laboratory. All were 3 to 12 months post-stroke and had mild to moderate paresis of an upper extremity. RESULTS: After an item analysis, two MAL tasks were eliminated. Revised participant MAL QOM scores were reliable (r =0.82). Validity was also supported. During the first observation period, the correlation between QOM and SIS Hand Function scale scores was 0.72. The corresponding correlation for QOM and accelerometry values was 0.52. Participant QOM and AOU scores were highly correlated (r = 0.92). CONCLUSIONS: The participant Motor Activity Log is reliable and valid in individuals with subacute stroke. It might be employed to assess the real-world effects of upper extremity neurorehabilitation and detect deficits in spontaneous use of the hemiparetic arm in daily life.

Uswatte G., Giuliani C., Winstein C., Zeringue A., Hobbs L. & Wolf S.L. (Oct 2006). Validity of accelerometry for monitoring real-world arm activity in patients with subacute stroke: evidence from the extremity constraint-induced therapy evaluation trial. Arch Phys Med Rehabil, 87(10):1340-5.

OBJECTIVE: To examine the psychometric properties of an objective method for assessing real-world arm activity in a large sample with subacute stroke. DESIGN: Validation study. SETTING: Community. PARTICIPANTS: Persons 3 to 9 months poststroke (N=169) with mild to moderate motor impairment of their hemiparetic arm enrolled in a multisite, randomized clinical trial of constraint-induced movement therapy. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Participants wore an accelerometer on each arm outside the laboratory for 3 days before and after treatment or an equivalent no-treatment period. They also completed the Actual Amount of Use Test (AAUT), which is an observational measure of spontaneous more-impaired arm use, and the Motor Activity Log (MAL), which is an interview assessing more-impaired arm use in daily life. RESULTS: Low-pass-filtered accelerometer recordings were reliable (r range, >.8) and stable (P range, >.48). Their validity was also supported. Correlations calculated across all participants at baseline between the ratio of more-impaired to less-impaired arm accelerometer recordings and AAUT and MAL scores were .60 and .52, respectively. CONCLUSIONS: Accelerometry provides an objective, real-world index of more-impaired arm activity with good psychometric properties.

Van den Berg-Emons R.J., Schasfoort F.C., De Vos L.A., Bussmann J.B. & Stam H.J. (2006 Nov 13). Impact of chronic pain on everyday physical activity. Eur J Pain. [Epub ahead of print]

Although patients with chronic pain are often considered to have reduced levels of everyday physical activity, data on their activity levels are scarce and inconclusive. Therefore, this study explored whether patients with chronic pain have reduced activity levels, as objectively measured with an activity monitor. The activity monitor is based on long-term ambulatory monitoring of signals from body-fixed accelerometers during everyday life, aimed at assessment of mobility-related activities. Measurements with the monitor were performed during a weekday (24h) in 18 patients with chronic pain and compared with measurements obtained from 18 gender and age matched healthy comparison subjects. The mean (SD) age of the patients was 44 (11) years, and the mean (SD) duration of their complaints was 8 (7) years. Compared with the healthy subjects, the duration of dynamic activities was not significantly reduced (p=0.10) in the patient group. Mean (SD) intensity of everyday physical activity was lower (p=0.03) in the patients than in the healthy comparison subjects (0.021 [0.006] g versus 0.026 [0.004] g), and patients spent more time lying down (47.0 [10.2]% versus 34.3 [5.6] %; p=0.000) and less time sitting (29.2 [8.9]% versus 36.4 [9.3]%; p=0.03) than the healthy comparison subjects. In spite of significant differences between patients and healthy comparison subjects for some aspects of the activity pattern (which may reflect pain behaviour), the impact of chronic pain on everyday physical activity was relatively small.

Ward J.A., Lukowicz P., Troster G. & Starner T.E. (Oct 2006). Activity recognition of assembly tasks using body-worn microphones and accelerometers. IEEE Trans Pattern Anal Mach Intell, 28(10):1553-67.

In order to provide relevant information to mobile users, such as workers engaging in the manual tasks of maintenance and assembly, a wearable computer requires information about the user’s specific activities. This work focuses on the recognition of activities that are characterized by a hand motion and an accompanying sound. Suitable activities can be found in assembly and maintenance work. Here, we provide an initial exploration into the problem domain of continuous activity recognition using on-body sensing. We use a mock “wood workshop” assembly task to ground our investigation. We describe a method for the continuous recognition of activities (sawing, hammering, filing, drilling, grinding, sanding, opening a drawer, tightening a vise, and turning a screwdriver) using microphones and three-axis accelerometers mounted at two positions on the user’s arms. Potentially “interesting” activities are segmented from continuous streams of data using an analysis of the sound intensity detected at the two different locations. Activity classification is then performed on these detected segments using linear discriminant analysis (LDA) on the sound channel and hidden Markov models (HMMs) on the acceleration data. Four different methods at classifier fusion are compared for improving these classifications. Using user-dependent training, we obtain continuous average recall and precision rates (for positive activities) of 78 percent and 74 percent, respectively. Using user-independent training (leave-one-out across five users), we obtain recall rates of 66 percent and precision rates of 63 percent. In isolation, these activities were recognized with accuracies of 98 percent, 87 percent, and 95 percent for the user-dependent, user-independent, and user-adapted cases, respectively.

Zakopoulos N., Spengos K., Tsivgoulis G., Zis V., Manios E. & Vemmos K. (Oct 2006). Assessment of blood pressure control in hypertensive stroke survivors: an ambulatory blood pressure monitoring study. Blood Pressure Monitoring, 11(5):235-41.

BACKGROUND: We compared the sensitivity of office blood pressure and ambulatory blood pressure monitoring recordings in evaluating the effectiveness of antihypertensive treatment and identified factors related to inadequate blood pressure control among hypertensive stroke survivors. METHODS: Office blood pressure and ambulatory blood pressure monitoring measurements were performed at 120+/-30 days after ictus in 187 first-ever consecutive hypertensive stroke survivors who were receiving blood pressure-lowering medications according to international guidelines. Handicap was assessed by the modified Rankin Scale. Blood pressure was regarded as controlled if office and daytime ambulatory systolic and diastolic blood pressure values were <140/90 and <135/85 mmHg, respectively. Patients were subclassified according to the degree of their nocturnal systolic blood pressure fall [(mean daytime values-mean night-time values)100/mean daytime values] as dippers (>or=10%), nondippers (>or=0% and <10%) and reverse dippers (<0%). RESULTS: Effective blood pressure control was documented in significantly (P<0.001) fewer patients using ambulatory blood pressure monitoring (32.1%) than those using office recordings (43.3%), whereas in 16% of the study population a masked lack of per-treatment blood pressure control (elevated ambulatory blood pressure in the presence of normal office blood pressure levels) was identified. The distribution of dipping patterns differed significantly (P=0.01) between controlled hypertensive individuals (normal office and ambulatory measurements) and patients with isolated ambulatory hypertension (dippers: 31.3 vs. 10.0%; nondippers:56.9 vs. 53.3%; reverse dippers: 11.8 vs. 36.7%). Logistic regression analysis revealed diabetes mellitus and functional independency (modified Rankin Scale score<2) as independent predictors of inadequate blood pressure control. CONCLUSION: Ambulatory blood pressure monitoring detects a substantial number of treated hypertensive stroke survivors with a masked lack of per-treatment blood pressure control, who present a higher prevalence of abnormal circadian blood pressure patterns (reverse dipping). Diabetes mellitus and poststroke functional independency are the main factors contributing to inadequate blood pressure control.

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