TY - JOUR AU - Noh, Jung Min AU - Im, SongHyun AU - Park, JooYong AU - Kim, Jae Myung AU - Lee, Miyoung AU - Choi, Ji-Yeob PY - 2025 DA - 2025/4/1 TI - Validation of Ecological Momentary Assessment With Reference to Accelerometer Data: Repeated-Measures Panel Study With Multilevel Modeling JO - J Med Internet Res SP - e59878 VL - 27 KW - telemedicine KW - wearable electronic devices KW - physical activity KW - mobile phone KW - wearables KW - smartphones KW - ecological momentary assessment KW - EMA KW - global physical activity questionnaire KW - GPAQ KW - Bouchard’s physical activity KW - multilevel modeling KW - females KW - women KW - males KW - men KW - sensors KW - evaluation KW - comparative KW - South Korea AB - Background: There is growing interest in the real-time assessment of physical activity (PA) and physiological variables. Acceleration, particularly those collected through wearable sensors, has been increasingly adopted as an objective measure of physical activity. However, sensor-based measures often pose challenges for large-scale studies due to their associated costs, inability to capture contextual information, and restricted user populations. Smartphone-delivered ecological momentary assessment (EMA) offers an unobtrusive and undemanding means to measure PA to address these limitations. Objective: This study aimed to evaluate the usability of EMA by comparing its measurement outcomes with 2 self-report assessments of PA: Global Physical Activity Questionnaire (GPAQ) and a modified version of Bouchard Physical Activity Record (BAR). Methods: A total of 235 participants (137 female, 98 male, and 94 repeated) participated in one or more 7-day studies. Waist-worn sensors provided by ActiGraph captured accelerometer data while participants completed 3 self-report measures of PA. The multilevel modeling method was used with EMA, GPAQ, and BAR as separate measures, with 6 subdomains of physiological activity (overall PA, overall excluding occupational, transport, exercise, occupational, and sedentary) to model accelerometer data. In addition, EMA and GPAQ were further compared with 6 domains of PA from the BAR as outcome measures. Results: Among the 3 self-reporting instruments, EMA and BAR exhibited better overall performance in modeling the accelerometer data compared to GPAQ (eg EMA daily: β=.387, P<.001; BAR daily: β=.394, P<.001; GPAQ: β=.281, P<.001, based on repeated-only participants with step counts from accelerometer as dependent variables). Conclusions: Multilevel modeling on 3 self-report assessments of PA indicates that smartphone-delivered EMA is a valid and efficient method for assessing PA. SN - 1438-8871 UR - https://www.jmir.org/2025/1/e59878 UR - https://doi.org/10.2196/59878 UR - http://www.ncbi.nlm.nih.gov/pubmed/40168069 DO - 10.2196/59878 ID - info:doi/10.2196/59878 ER -