Xi Yang1, Russell Jago2, Qian Zhang3, Yu Ying Wang4, Jian Zhang3, Wen Hua Zhao3. 1. National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing 100050, China; Chinese Center for Disease Control and Prevention, Beijing 102206, China. 2. Center for Exercise, Nutrition and Health Sciences, School for Policy Studies, University of Bristol, Bristol, BS8 1TZ, UK. 3. National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing 100050, China. 4. Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Abstract
OBJECTIVE: In this study we aimed to examine the reliability and validity of the wristband activity monitor against the accelerometer for children.. METHODS: A total of 99 children (mean age = 13.0 ± 2.5 y) wore the two monitors in a free-living context for 7 days. Reliability was measured by intraclass correlation to evaluate consistency over time. Repeated-measures analyses of variance was used to detect differences across days. Spearman's correlation coefficient (rho), median of absolute percentage error, and Bland-Altman analyses were performed to assess the validity of the wristband against the ActiGraph accelerometer. The optimal number of repeated measures for the wristband was calculated by using the Spearman-Brown prophecy formula. RESULTS: The wristband had high reliability for all variables, although physical activity data were different across 7 days. A strong correlation for steps (rho: 0.72, P < 0.001), and moderate correlations for time spent on total physical activity (rho: 0.63, P < 0.001) and physical activity energy expenditure (rho: 0.57, P < 0.001) were observed between the wristband and the accelerometer. For different intensities of physical activity, weak to moderate correlations were found (rho: 0.38 to 0.55, P < 0.001). CONCLUSION: The wristband activity monitor seems to be reliable and valid for measurement of overall children's physical activity, providing a feasible objective method of physical activity surveillance in children.
OBJECTIVE: In this study we aimed to examine the reliability and validity of the wristband activity monitor against the accelerometer for children.. METHODS: A total of 99 children (mean age = 13.0 ± 2.5 y) wore the two monitors in a free-living context for 7 days. Reliability was measured by intraclass correlation to evaluate consistency over time. Repeated-measures analyses of variance was used to detect differences across days. Spearman's correlation coefficient (rho), median of absolute percentage error, and Bland-Altman analyses were performed to assess the validity of the wristband against the ActiGraph accelerometer. The optimal number of repeated measures for the wristband was calculated by using the Spearman-Brown prophecy formula. RESULTS: The wristband had high reliability for all variables, although physical activity data were different across 7 days. A strong correlation for steps (rho: 0.72, P < 0.001), and moderate correlations for time spent on total physical activity (rho: 0.63, P < 0.001) and physical activity energy expenditure (rho: 0.57, P < 0.001) were observed between the wristband and the accelerometer. For different intensities of physical activity, weak to moderate correlations were found (rho: 0.38 to 0.55, P < 0.001). CONCLUSION: The wristband activity monitor seems to be reliable and valid for measurement of overall children's physical activity, providing a feasible objective method of physical activity surveillance in children.
Authors: Marco Giurgiu; Simon Kolb; Carina Nigg; Alexander Burchartz; Irina Timm; Marlissa Becker; Ellen Rulf; Ann-Kathrin Doster; Elena Koch; Johannes B J Bussmann; Claudio Nigg; Ulrich W Ebner-Priemer; Alexander Woll Journal: BMJ Open Sport Exerc Med Date: 2022-05-12