Anomaly detection to predict relapse risk in schizophrenia.

The integration of technology in clinical care is growing rapidly and has become especially relevant during the global COVID-19 pandemic. Smartphone-based digital phenotyping, or the use of integrated sensors to identify patterns in behavior and symptomatology, has shown potential in detecting subtle moment-to-moment changes. These changes, often referred to as anomalies, represent significant deviations from an individual's baseline, may be useful in informing the risk of relapse in serious mental illness. Our investigation of smartphone-based anomaly detection resulted in 89% sensitivity and 75% specificity for predicting relapse in schizophrenia. These results demonstrate the potential of longitudinal collection of real-time behavior and symptomatology via smartphones and the clinical utility of individualized analysis. Future studies are necessary to explore how specificity can be improved, just-in-time adaptive interventions utilized, and clinical integration achieved.

Brief Report: Reactivity to Accelerometer Measurement among Adolescents with Autism Spectrum Disorder.

The purpose of this study was to examine reactivity to accelerometer measurement among adolescents with autism spectrum disorder (ASD). A sample of 23 adolescents with ASD (aged 15.00 ± 1.57 years old; 17 boys) wore triaxial accelerometers for at least 8 h per day for seven consecutive days. Descriptive statistics, including arithmetic means and standard deviations, as well as analysis of covariances with repeated measures (ANCOVAs) were conducted, controlling for participant body mass index and gender. While differences were not statistically significant, they exceed reactivity-based recommendations and have implications for future research with adolescents with ASD. The inverse reactivity pattern among adolescents with ASD is a unique finding that has important implications for research in this area.

Wearable strain sensor suit for infants to measure limb movements under interaction with caregiver.

Development of motion capture technology has enabled the measurement of body movements over long periods of time in daily life. Although accelerometers have been used as primary sensors, problems arise when they are used to measure the movements of infants. Because infants and caregivers interact frequently, accelerometer data from infants may be significantly distorted by a caregiver's movement. To overcome this problem, a strain sensor suit was developed for infants to measure flexion and extension movements of the limbs. A case study was performed to analyze the strain sensor data of an infant in relation to the accelerometer data of the infant's and a caregiver's body under various types of infant-caregiver interaction. The results demonstrated that the strain sensor data had low correlation with the accelerometer data of the infant and caregiver while the accelerometer data between infant and caregiver had higher correlation. This suggests that the strain sensor is suitable to detect limbs' angular displacements mostly independent from the translational body movements exerted by a caregiver.

Accelerometer- and Pedometer-Based Physical Activity Interventions Among Adults With Cardiometabolic Conditions: A Systematic Review and Meta-analysis.

Importance: Accelerometers and pedometers are accessible technologies that could have a role in encouraging physical activity (PA) in line with current recommendations. However, there is no solid evidence of their association with PA in participants with 1 or more cardiometabolic conditions such as diabetes, prediabetes, obesity, and cardiovascular disease. Objectives: To assess the association of accelerometer- and pedometer-based interventions with increased activity and other improved health outcomes in adults with cardiometabolic conditions and to examine characteristics of the studies that could influence the association of both interventions in improving PA. Data Sources: Records from MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, the Cumulative Index to Nursing and Allied Health, and PsycINFO were searched from inception until August 2018 with no language restriction. Study Selection: Randomized clinical trials or cluster randomized clinical trials evaluating the use of wearable technology devices such as pedometers and accelerometers as motivating and monitoring tools for increasing PA were included. After removing duplicates, the searches retrieved 5762 references. Following abstract and title screening of 1439 references and full-text screening of 107 studies, 36 studies met inclusion criteria. Data Extraction and Synthesis: Mean difference in PA was assessed by random-effects meta-analysis. Where the scale was different across studies, the standardized mean difference was used instead. Heterogeneity was quantified using the I2 statistic and explored using mixed-effects metaregression. This study was registered with PROSPERO and followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline. Main Outcomes and Measures: The primary outcome was objectively measured PA in the short to medium term (postintervention to 8 months' follow-up). Results: Thirty-six randomized clinical trials (20 using accelerometers and 16 using pedometers) involving 5208 participants were eligible for review. Meta-analysis involving 32 of these trials (4856 participants) showed medium improvements in PA: accelerometers and pedometers combined vs comparator showed a small significant increase in PA overall (standardized mean difference, 0.39 [95% CI, 0.28-0.51]; I2 = 60% [95% CI, 41%-73%]) in studies of short to medium follow-up over a mean (SD) of 32 (28.6) weeks. Multivariable metaregression showed improved association with PA for complex interventions that involved face-to-face consultation sessions with facilitators (ß = 0.36; 95% CI, 0.17-0.55; P < .001) and pedometer-based interventions (ß = 0.30; 95% CI, 0.08-0.52; P = .002). Conclusions and Relevance: In this study, complex accelerometer- and pedometer-based interventions led to significant small to medium improvements in PA levels of people with cardiometabolic conditions. However, longer-term trials are needed to assess their performance over time. This study found no evidence that simple self-monitored interventions using either pedometers or accelerometers are associated with improvements in PA.

Use of previous-day recalls of physical activity and sedentary behavior in epidemiologic studies: results from four instruments.

BACKGROUND: The last few years have seen renewed interest in use-of-time recalls in epidemiological studies, driven by a focus on the 24-h day [including sleep, sitting, and light physical activity (LPA)] rather than just moderate-vigorous physical activity (MVPA). This paper describes four different computerised use-of-time instruments (ACT24, PAR, MARCA and cpar24) and presents population time-use data from a collective sample of 8286 adults from different population studies conducted in Australia/New Zealand, Germany and the United States. METHODS: The instruments were developed independently but showed a number of similarities: they were self-administered through the web or used computer-assisted telephone interviews; all captured energy expenditure using variants of the Ainsworth Compendium; each had been validated against criterion measures; and they used a domain structure whereby activities were aggregated under categories such as Personal Care and Work. RESULTS: Estimates of physical activity level (average daily rate of energy expenditure in METs) ranged from 1.53 to 1.78 in the four studies, strikingly similar to population estimates derived from doubly labelled water. There was broad agreement in the amount of time spent in sleep (7.2-8.6 h), MVPA (1.6-3.1 h), personal care (1.6-2.4 h), and transportation (1.1-1.8 h). There were consistent sex differences, with women spending 28-81% more time on chores, 8-40% more time in LPA, and 3-39% less time in MVPA than men. CONCLUSIONS: Although there were many similarities between instruments, differences in operationalizing definitions of sedentary behaviour and LPA resulted in substantive differences in the amounts of time reported in sedentary and physically active behaviours. Future research should focus on deriving a core set of basic activities and associated energy expenditure estimates, an agreed classificatory hierarchy for the major behavioural and activity domains, and systems to capture relevant social and environmental contexts.

Recovery of physical activity after cesarean delivery and its relationship with pain.

Pain and physical activity are tightly intertwined. Although their relationship has been explored in chronic pain conditions, we know little about the pattern of recovery in activity and its short- and long-term relationship with pain after surgery. We recruited 103 women undergoing elective cesarean delivery and acquired daily pain assessments and hourly steps in 98 of them for 2 months after surgery. Compliance was good, with 78% of subjects missing less than 7 days of activity. Study personnel required daily checking for compliance and 20 minutes per subject per week in study. Activity increased over the first 2 postoperative months in a log(time) manner. The slope of each modeled individual curve for activity was inversely correlated (r = -0.54; P < 0.0001) with worst daily pain. After removing these 2-month trends, pain and activity within an individual day were negatively associated with each point increase in pain being inversely associated with -119 steps (95% confidence interval [CI] = -214 to -25; P = 0.013). A patient's previous experience of pain was not associated with current activity as well as current activity was not associated with future pain scores. These data, although limited by the study of a single operation in a unique social circumstance with low risk of chronic postsurgical pain, demonstrate feasibility of measuring hourly activity for 2 months after surgery. Recovery from pain and inactivity are tightly correlated, and the negative relationship between within-day pain and activity without interday carryover relationships is in stark contrast to findings in chronic pain conditions.

Self-monitoring and reminder text messages to increase physical activity in colorectal cancer survivors (Smart Pace): a pilot randomized controlled trial.

BACKGROUND: Over 1.3 million people live with colorectal cancer in the United States. Physical activity is associated with lower risk of colorectal cancer recurrence and mortality. Interventions are needed to increase physical activity in colorectal cancer survivors. METHODS: We conducted a 2-arm non-blinded pilot randomized controlled trial at the University of California, San Francisco among 42 individuals who had completed curative-intent treatment for colorectal cancer to determine the feasibility and acceptability of a 12-week (84 days) physical activity intervention using a Fitbit Flex™ and daily text messages. Participants were randomized 1:1 to receive the intervention with print educational materials or print educational materials alone. We explored the impact of the intervention versus usual care on physical activity using ActiGraph GT3X+ accelerometers pre-/post-intervention. RESULTS: We screened 406 individuals and randomized 42 to intervention (n = 21) or control (n = 21) groups. During the 12-week study, the intervention arm wore their Fitbits a median of 74 days [88% of days in study period, interquartile range: 23-83 days] and responded to a median of 34 (out of 46) text messages that asked for a reply (interquartile range: 13-38 text messages). Among the 16 intervention participants who completed the feedback survey, the majority (88%) reported that the intervention motivated them to exercise and that they were satisfied with their experience. No statistically significant difference in change in moderate-to-vigorous physical activity was found from baseline to 12 weeks between arms. CONCLUSION: A 12-week physical activity intervention with a Fitbit and text messages was feasible and acceptable among colorectal cancer patients after curative treatment. Larger studies are needed to determine whether the intervention increases physical activity. TRIAL REGISTRATION: Clinicaltrials.gov Identifier NCT02966054 . Registered 17 November 2016, retrospectively registered.

Physical activity intensity and subjective well-being in healthy adults.

The effect of physical activity intensity on subjective well-being has not been well established. We examined this relationship among 419 healthy adults using objective and subjective physical activity measurements (sample size varied among well-being assessments). For accelerometers, light-intensity physical activity positively associated with psychological well-being (n = 150) and negatively associated with depression (n = 99); moderate intensity negatively associated with pain severity (n = 419) and positively associated with psychological well-being; sedentary behavior negatively associated with psychological well-being and positively associated with depression (ps < .05). These findings were generally consistent with subjective measurements of physical activity (Question 8, Paffenbarger Questionnaire). Higher levels of sedentary behavior are associated with lower subjective well-being.

Substituting Sedentary Time With Physical Activity in Fibromyalgia and the Association With Quality of Life and Impact of the Disease: The al-Ándalus Project.

OBJECTIVE: There is an overall awareness of the detrimental health effects of sedentary time (ST) in fibromyalgia; however, data are limited on how replacement of ST with physical activity (PA) of different intensity may be related to health in this condition. The aim of this study was to examine how a substitution of ST with light PA (LPA) or moderate-to-vigorous PA (MVPA) is associated with quality of life and disease impact. METHODS: This study comprised 407 women with fibromyalgia, mean ± SD age 51.4 ± 7.6 years. The time spent in ST and PA was measured with triaxial accelerometry. Quality of life and disease impact were assessed using the Short Form 36 (SF-36) health survey and the Revised Fibromyalgia Impact Questionnaire (FIQR), respectively. The substitution of ST with an equivalent time of LPA or MVPA and the associated outcomes were examined using isotemporal substitution analyses. RESULTS: Substituting 30 minutes of ST with LPA in the isotemporal model was associated with better scores in bodily pain (B = 0.55), vitality (B = 0.74), and social functioning (B = 1.45) according to the SF-36, and better scores at all of the domains (function, overall impact, symptoms, and total impact) of the FIQR (B ranging from -0.95 to -0.27; all P < 0.05). When ST was replaced with MVPA, better physical role (B = 2.30) and social functioning (B = 4.11) of the SF-36 and function of the FIQR (B = -0.73) were observed (all P < 0.05). CONCLUSION: In regression models, allocation of time of sedentary behavior to either LPA or MVPA was associated with better quality of life and lower disease impact in women with fibromyalgia.

The effect of education and supervised exercise on physical activity, pain, quality of life and self-efficacy - an intervention study with a reference group.

BACKGROUND: Individuals with knee and hip osteoarthritis (OA) are less physically active than people in general, and many of these individuals have adopted a sedentary lifestyle. In this study we evaluate the outcome of education and supervised exercise on the level of physical activity in individuals with knee or hip OA. We also evaluate the effect on pain, quality of life and self-efficacy. METHODS: Of the 264 included individuals with knee or hip OA, 195 were allocated to the intervention group. The intervention group received education and supervised exercise that comprised information delivered by a physiotherapist and individually adapted exercises. The reference group consisted of 69 individuals with knee or hip OA awaiting joint replacement and receiving standard care. The primary outcome was physical activity (as measured with an accelerometer). The secondary outcomes were pain (Visual Analog Scale), quality of life (EQ-5D), and self-efficacy (Arthritis Self-Efficacy Scale, pain and other symptoms subscales). Participants in both groups were evaluated at baseline and after 3 months. The intervention group was also evaluated after 12 months. RESULTS: No differences were found in the number of minutes spent in sedentary or in physical activity between the intervention and reference groups when comparing the baseline and 3 month follow-up. However, there was a significant difference in mean change (mean diff; 95% CI; significance) between the intervention group and reference group favoring the intervention group with regard to pain (13; 7 to 19; p < 0.001), quality of life (- 0.17; - 0.24 to - 0.10; p < 0.001), self-efficacy/other symptoms (- 5; - 10 to - 0.3; p < 0.04), and self-efficacy/pain (- 7; - 13 to - 2; p < 0.01). Improvements in pain and quality of life in the intervention group persisted at the 12-month follow-up. CONCLUSIONS: Participation in an education and exercise program following the Swedish BOA program neither decreased the average amount of sedentary time nor increased the level of physical activity. However, participation in such a program resulted in decreased pain, increased quality of life, and increased self-efficacy. TRIAL REGISTRATION: The trial is registered with ClinicalTrials.gov. Registration number: NCT02022566 . Retrospectively registered 12/18/2013.

Cognitive function and the agreement between self-reported and accelerometer-accessed physical activity.

BACKGROUND: Numerous studies have reported weak or moderate correlations between self-reported and accelerometer-assessed physical activity. One explanation is that self-reported physical activity might be biased by demographic, cognitive or other factors. Cognitive function is one factor that could be associated with either overreporting or underreporting of daily physical activity. Difficulties in remembering past physical activities might result in recall bias. Thus, the current study examines whether the cognitive function is associated with differences between self-reported and accelerometer-assessed physical activity. METHODS: Cross-sectional data from the population-based Activity and Function in the Elderly in Ulm study (ActiFE) were used. A total of 1172 community-dwelling older adults (aged 65-90 years) wore a uniaxial accelerometer (activPAL unit) for a week. Additionally, self-reported physical activity was assessed using the LASA Physical Activity Questionnaire (LAPAQ). Cognitive function was measured with four items (immediate memory, delayed memory, recognition memory, and semantic fluency) from the Consortium to Establish a Registry for Alzheimer's Disease Total Score (CERAD-TS). RESULTS: Mean differences of self-reported and accelerometer-assessed physical activity (MPA) were associated with cognitive function in men (rs = -.12, p = .002) but not in women. Sex-stratified multiple linear regression analyses showed that MPA declined with high cognitive function in men (ß = -.13; p = .015). CONCLUSION: Results suggest that self-reported physical activity should be interpreted with caution in older populations, as cognitive function was one factor that explained the differences between objective and subjective physical activity measurements.

Grado de acuerdo entre la acelerometría y el Cuestionario Internacional de Actividad Física en pacientes supervivientes de cáncer de mama / Level of agreement between accelerometry and the International Physical Activity Questionnaire in breast cancer survivors

Objetivo primario: Analizar el grado de acuerdo entre la medida autoinformada provista por el International Physical Activity Questionnaire (IPAQ) y la medida objetiva aportada por los acelerómetros (ActiGraph) en mujeres supervivientes a un cáncer de mama. Objetivo secundario: Evaluar la percepción de sensación de fatiga de estas pacientes, así como su estado de ánimo y la fuerza prensil. También quisimos comprobar la relación entre el soporte social y la práctica de actividad física. Material y método: Las 10 participantes llevaron un acelerómetro 9 días y a su retirada completaron los cuestionarios IPAQ, PIPER, POMS, uno de valoración de su soporte social y se tomaron medidas de la dinamometría de ambas manos. Se procedió al análisis inferencial usando el coeficiente de correlación de Spearman (rs) entre la AF total y las diferentes categorías por intensidad contabilizada por el ActiGraph, y la recogida por el IPAQ. Los datos fueron comparados en min/día realizando actividad sedentaria, ligera, moderada o intensa. Resultados: No se encontró concordancia entre los datos arrojados por ambos instrumentos, a excepción de la categoría sedentaria/sentado, con un rs=0,714 (p=0,02). Los minutos/día totales de AF del acelerómetro ha sido un 263% más elevados que del cuestionario, por lo que este último infravalora la AF. Respecto a las dimensiones emocionales evaluadas, la confusión/aturdimiento se relacionó significativamente con la sensación de fatiga (rs=0,85, p=0,002) y la fatiga total (rs=0,71, p=0,02). También apareció una relación inversa entre vigor/actividad y la dimensión cognitiva de la fatiga (rs=-0,63, p=0,04). La sensación de fatiga/inercia también se relacionó inversamente con la fuerza prensil de la mano del lado intervenido. También fue inversa la relación entre el soporte familiar y de amigos y el tiempo en posición tumbado o en decúbito (rs=-0,77, p=0,008 y rs=-0,84, p=0,002, respectivamente) y entre este apoyo de los amigos y la rabia/hostilidad (rs=-0,64, p=0,04) Conclusiones: Había un grado de acuerdo limitado en la medida de la AF y las conductas sedentarias del IPAQ y del Actigraph. El primero no parece ser muy adecuado para esta población, y para el acelerómetro necesitaríamos valores de referencia más en consonancia con estas mujeres

Primary objective: To analyse the level of agreement between that measured by the self-report provided by the IPAQ (International Physical Activity Questionnaire) and the objective measurement provided by accelerometers (ActiGraph) in breast cancer patients. Secondary objective: To evaluate the perception of their fatigue in these patients, as well as their state of mind and prehensile strength. An attempt was also made to determine the relationship between social support and the practice of physical activity. Material and method: The 10 patients carried an accelerometer for 9 days, and afterwards they completed the IPAQ, Piper Fatigue Scale (PFS), and Profile of Mood States (POMS) questionnaires. Their social support was also assessed, and dynamometry measurements were taken on both hands. An inferential analysis was performed using the Spearman correlation coefficient (rs) between the total physical activity (PA) and the different categories by the intensity measured by ActiGraph, and that recorded in the IPAQ. The data were compared in minutes/day of sedentary, light, moderate or intense activity. Results: No agreement was found between the data provided by both tools, with the exception of the sedentary/seated category with a Spearman coefficient (rs) of 0.714 (P=.02). The total minutes/day of the accelerometer was 263% higher than the questionnaire, thus this latter undervalued the PA. As regards the emotional dimensions evaluated, confusion/bewilderment was significantly associated with feeling of fatigue (rs=0.85, P=.002), and total fatigue (rs=0.71, P=.02). An inverse relationship was also observed between vigour/activity and cognitive dimension of fatigue (rs=-0.63, P=.04). The feeling of fatigue/inertia was also inversely associated with prehensile strength of the hand on the side of the intervention. There was also an inverse relationship between family and friends support and the time in the lying down or decubitus position (rs=-0.77, P=.008 and rs=-0.84, P=.002, respectively) and between this support by friends and anger/hostility (rs=-0.64, P=.04)Conclusions: There was a limited level of agreement in the measurement of PA and sedentary behaviours of the IPAQ and Actigraph. The first one does not seem to very suitable for this population, and reference values more in line with these women are needed for the accelerometer

Association of Habitual Physical Activity With Cardiovascular Risk Factors and Target Organ Damage in Adolescents and Young Adults.

BACKGROUND: We aimed to (1) compare a subjective and objective measure of habitual physical activity (PA), (2) determine the association of PA and cardiovascular risk factors, and (3) test the hypothesis that PA is an independent determinant of target organ damage in youth. METHODS: Cross-sectional analysis of youth with and without type 2 diabetes [mean age = 22 (3.9) y]. PA was measured with International Physical Activity Questionnaire and Actical accelerometer. Target organ damage was assessed with echocardiography and peripheral arterial testing. Subjects were stratified into tertiles of total PA, and differences were tested by analysis of variance and χ2 tests. General linear models tested for independent associations. RESULTS: The correlation between International Physical Activity Questionnaire and accelerometry was weak (r = .23, P = .0003). Less active subjects had worse cardiovascular risk profiles and target organ damage, including stiffer arteries (P < .01). These outcome differences did not reach statistical significance when adjusted for covariates, such as lipid levels and glycemic control. CONCLUSION: Survey assessment of PA is complicated by inaccurate reporting. There is a strong association of habitual PA with cardiovascular risk factor clustering. PA may exert its beneficial effect on arterial stiffness in obese youth through improved glycemic control.

Physical activity level behavior according to the day of the week in postmenopausal women / Comportamiento del nivel de actividad física de acuerdo con el día de la semana en las mujeres posmenopáusicas / Comportamento do nível da atividade física de acordo com o dia da semana em mulheres na pós-menopausa

Objective. The aim of this study was to compare the differences in the levels of physical activity practiced during the weekdays and weekends in obese postmenopausal women. Method. 117 post-menopausal women aged between 50 and 79 were evaluated. To estimate the percentage of body fat the Dual-Energy X-ray Absorptiometry was used. The assessment of physical activity level was obtained using a tri-axial accelerometer. Results. There was a significant increase in physical activity-light and a significant decrease in physical activity moderate, vigorous, moderate-vigorous and overall number of counts at the weekend compared to the weekdays. The physical activity moderate-vigorous reduced by an average of 38.6% (p<0.001) at the weekend compared to the weekdays. Conclusion. Obese post-menopausal women presented decreasing physical activity moderate, vigorous, moderate-vigorous and overall number of counts at the weekends compared to the weekdays and an increase in physical activity light (AU)

Objetivo. Comparar las diferencias en los niveles de actividad física practicada durante los días de semana y fines de semana en las mujeres obesas posmenopáusicas. Método. Se evaluaron 117 mujeres post-menopáusicas de edades comprendidas entre 50 y 79años. Para calcular el porcentaje de grasa corporal se utilizó la absorciometría de rayos X de doble energía. Se obtuvo la evaluación del nivel de actividad física mediante un acelerómetro triaxial. Resultados. Hubo un aumento significativo en la actividad física suave y una disminución significativa en la actividad física moderada, vigorosa, moderada-vigorosa y el número total de recuentos en el fin de semana en comparación con los días de la semana. La actividad física moderada-vigorosa se redujo en un promedio del 38.6% (p<0.001) en el fin de semana en comparación con los días de la semana. Conclusión. Las mujeres obesas posmenopáusicas presentaron disminución de la actividad física moderada, vigorosa, moderada-vigorosa y el número total de recuentos en los fines de semana en comparación con los días de la semana y un aumento de actividad física suave (AU)

Objetivo. Comparar as diferenças nos níveis de atividade física feitas durante a semana e fins de semana em mulheres pós-menopáusicas com obesidade. Método. foram avaliadas 117 mulheres na pós-menopausa com idade entre 50 e 79 anos. Para o cálculo do percentual de gordura corporal foi utilizado raios-X absorciometria de dupla energia. Se obteve a evolução do nível de atividade física por um acelerómetro triaxial. Resultados. Houve um aumento significativo na atividade física leve e uma diminuição significativa na atividade física moderada, vigorosa, moderada a vigorosa e o número total de contagens no fim de semana em comparação com a semana. Atividade física moderada a vigorosa foi reduzida por uma média de 38.6% (p<0.001) no fim de semana em comparação com a semana. Conclusão. As mulheres obesas na pós menopausa apresentaram uma diminuição da atividade física moderada, vigorosa, moderada a vigorosa e o no número total de contagens nos fins de semana em comparação com a semana e aumento da atividade física suave (AU)

Feasibility of objectively measured physical activity and sedentary behavior in patients with malignant pleural effusion.

PURPOSE: Malignant pleural effusion (MPE) affects 1 million people worldwide annually and can significantly impair physical activity. Accelerometry is a validated method of objectively assessing physical activity. The purpose of this study was to determine the compliance in patients with MPE to accelerometry and describe their activity. METHODS: Patients with MPE wore an Actigraph GT3X accelerometer over a 7-day continuous wear protocol. Compliance was measured as the percent of patients who had ≥4 valid days (i.e., 8-h/day of waking wear-time). Eastern Cooperative Oncology Group performance status was documented the day of actigraphy initialization. RESULTS: Forty-six patients with MPE received accelerometers; 44 (95.7%) returned their device. No complications were reported on their use. Forty subjects (90.9%) had ≥4 valid days of wear-time. Patients spent most of their waking hours sedentary [mean 11.0 h (SD 1.95)], with limited participation in moderate and vigorous physical activity [mean 9.5 min (SD 14.16)]. Compared to patients with better performance status (n = 32), patients with poorer performance status (n = 11) spent significantly more hours/day sedentary [mean difference 2.1 (CI 0.86-3.32); p = 0.001], as did those who survived <3 months (n = 5) compared to >12 months (n = 27) [mean difference 2.6 (CI 0.49-4.77); p = 0.013). CONCLUSION: Accelerometry was applied successfully in patients with MPE with high compliance and no adverse events. This is the first reported objectively measured physical activity in patients with MPE and revealed high sedentary behavior and low physical activity. The data reflected patient performance status and discriminated between survival groups. Accelerometry can provide a useful measure for future interventional studies in patients with MPE.

Does reactivity to accelerometers occur in a single trial? Brief report in a sample of young adults.

This study aimed to test acute reactivity during a physical activity in an outdoor setting and to verify the relative perceived performance. In all, 38 volunteers wore accelerometers or not and completed two 20-minute sessions of self-selected pace physical activity. Covered distance, exertional responses, and perceived efficacy were recorded at the end of every session. Relevant finding of this study has been that reactivity to accelerometers also occurs in acute condition. Consequently, this condition leads to a better performance and a greater perceived exertion. Moreover, this situation seems to occur in a state of awareness.

Effects of dyadic planning on physical activity in couples: A randomized controlled trial.

OBJECTIVE: Action planning can help translate physical activity intentions into action by linking situational cues with behavioral responses. Dyadic planning extends action planning and refers to target persons forming plans for their own behavior change together with partners. This study investigated whether a dyadic planning intervention could increase physical activity in target persons and their partners, whether these effects were moderated by relationship quality and mediated by action control, activity-specific received partner support, and control. METHOD: Couples (n = 338; target persons randomized) were randomly assigned to (a) a dyadic planning condition (DPC); (b) an individual planning condition (IPC), in which target persons planned and partners worked on a distractor task; or (c) a control condition (CC), in which couples worked on a distractor task. During 3 assessments up to 6 weeks postintervention, moderate (primary outcome) and vigorous activity were objectively measured; other variables were self-reported. Multilevel and path models were fit. RESULTS: There were no beneficial direct effects of the intervention for DPC target persons. Over time, DPC partners' vigorous activity increased, but decreased again. At lower relationship quality, DPC target persons' activity decreased, whereas IPC target persons' vigorous activity increased. Mediation hypotheses were not supported. Mutual influence models indicated positive effects of partners' on target persons' moderate activity in DPC and CC, whereas for IPC, negative effects of target persons' on partners' moderate activity emerged. CONCLUSIONS: Findings revealed the complexity of effects of dyadic planning on behavior change. Adding relationship quality to the equation clarified effects of DPC and IPC on physical activity. (PsycINFO Database Record

Beyond Neighborhood Food Environments: Distance Traveled to Food Establishments in 5 US Cities, 2009-2011.

INTRODUCTION: Accurate conceptualizations of neighborhood environments are important in the design of policies and programs aiming to improve access to healthy food. Neighborhood environments are often defined by administrative units or buffers around points of interest. An individual may eat and shop for food within or outside these areas, which may not reflect accessibility of food establishments. This article examines the relevance of different definitions of food environments. METHODS: We collected data on trips to food establishments using a 1-week food and travel diary and global positioning system devices. Spatial-temporal clustering methods were applied to identify homes and food establishments visited by study participants. RESULTS: We identified 513 visits to food establishments (sit-down restaurants, fast-food/convenience stores, malls or stores, groceries/supermarkets) by 135 participants in 5 US cities. The average distance between the food establishments and homes was 2.6 miles (standard deviation, 3.7 miles). Only 34% of the visited food establishments were within participants' neighborhood census tract. Buffers of 1 or 2 miles around the home covered 55% to 65% of visited food establishments. There was a significant difference in the mean distances to food establishments types (P = .008). On average, participants traveled the longest distances to restaurants and the shortest distances to groceries/supermarkets. CONCLUSION: Many definitions of the neighborhood food environment are misaligned with individual travel patterns, which may help explain the mixed findings in studies of neighborhood food environments. Neighborhood environments defined by actual travel activity may provide more insight on how the food environment influences dietary and food shopping choices.

Examining strategies to improve accelerometer compliance for individuals living with schizophrenia.

OBJECTIVE: This study examined the feasibility and effect of 2 investigator-based and 2 participant-based strategies on accelerometer wear time in individuals living with schizophrenia in order to improve accelerometry compliance. METHOD: Four adults with schizophrenia were asked to wear an accelerometer for 1 week during the baseline, intervention, and follow-up phases of a study that evaluated exercise counseling. To encourage participants to wear their accelerometers, investigators modeled proper accelerometer use, provided verbal and written instructions, and placed reminder phone calls. Participants were also given wear time logs and reminder magnets. RESULTS: All participants wore their accelerometers for the required amount of time during the study. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Researchers should use multiple techniques to help ensure compliance. Research is needed to identify the most effective combination of strategies for this population.

Differences in demographic, behavioral, and biological variables between those with valid and invalid accelerometry data: implications for generalizability.

BACKGROUND: The exclusion of participants with invalid accelerometry data (IAD) may lead to biased results and/or lack of generalizability in large population studies. The purpose of this study was to investigate whether demographic, behavioral, and biological differences occur between those with IAD and valid accelerometry data (VAD) among adults using a representative sample of the civilian noninstitutionalized U.S. population. METHODS: Ambulatory participants from NHANES (2003-2004) who were 20-85 years of age were included in the current study and wore an ActiGraph 7164 accelerometer for 7 days. A "valid person" was defined as those with 4 or more days of at least 10+ hrs of monitoring per day. Among adults (20-85 yrs), 3088 participants provided VAD and 987 provided IAD. Demographic, behavioral, and biological information were obtained from the household interview or from data obtained in a mobile examination center. RESULTS: Differences were observed in age, BMI, ethnicity, education, smoking status, marital status, use of street drugs, current health status, HDL-cholesterol, C-reactive protein, self-reported vigorous physical activity, and plasma glucose levels between those with VAD and IAD. CONCLUSIONS: Investigators should take into consideration the potential cut-off bias in interpreting results based on data that excludes IAD participants.