Collecting accelerometry data among adolescents: Lessons learns from the field (Preprint)

BACKGROUND While physical inactivity remains a pervasive public health problem, issues surrounding measuring physical activity plague researchers. Accelerometers are the gold-standard tool to assess physical activity behavior. However, accelerometer wear compliance varies by population and is influenced by factors, such as comfort and product features, among others. While compliance and acceptability of wrist-worn accelerometers is superior to hip-worn accelerometers, issues with compliance remain and likely vary by demographics and subpopulations. OBJECTIVE The purpose of this study is to compare the effects of three consumer-grade accelerometer protocols on wear compliance among adolescents. METHODS Move More, Get More (MMGM) is a an after-school sports sampling program to increase physical activity and physical literacy urban middle schoolers. Study participants were provided a Garmin VivoFit4 accelerometer watch; participant steps and physical activity were measured during the study period. Three methods of data collection were used to assess physical activity: 1) Continuous wear, self-sync, 2) Continuous wear, researcher-sync, and 3) Intermittent wear, researcher-sync. A one-way analysis of variance was conducted to assess between-group differences. RESULTS Mean valid days were significantly higher at baseline (F=27.52, p<0.001) and 6 months (F=9.98, p<0.001) of the intermittent wear, researcher-synced condition than for both the continuous wear conditions, and significantly higher at 3 months (F=4.05, p<0.05) for the continuous wear, research-synced condition. CONCLUSIONS Study findings suggest that intermittent wear, researcher-synced protocol significantly improve wear-time compliance and meets recommendations needed for reliable estimates of physical activity compared to continuous wear protocols as measured by mean valid days. To our knowledge, there are no studies comparing accelerometer protocols specifically for consumer-grade, wrist-worn accelerometers among adolescence, a population that has lower compliance rates compared to other age groups. INTERNATIONAL REGISTERED REPORT RR2-10.2196/37126