Comparison of Actical and ActiGraph Accelerometers for Measuring Young Children\u27s Physical Activity Levels and Sedentary Time

Young children\u27s activity and sedentary time were simultaneously measured via the Actical method (i.e., Actical accelerometer and Pfeiffer et al.\u27s cut-points) and the ActiGraph method (i.e., ActiGraph accelerometer and Pate et al.\u27s cut-points) at both 15s and 60s epochs to explore possible differences between these two measurement approaches. For seven consecutive days, participants (n = 23) wore both the Actical and ActiGraph side-by-side on an elastic neoprene belt. Device-specific cut-points were applied. Paired sample t-tests were conducted to determine the differences in participants\u27 daily average activity levels and sedentary time (mins/hr) measured by the two devices at 15s and 60s time sampling intervals. Bland-Altman plots were used to examine agreement between Actical and ActiGraph accelerometers. Regardless of epoch length, Actical accelerometers reported significantly higher rates of sedentary time (15s: 42.7 mins/hr vs. 33.5 mins/hr; 60s: 39.4 mins/hr vs. 27.1 mins/hr). ActiGraph accelerometers captured significantly higher rates of moderate-to-vigorous physical activity (15s: 9.2 mins/hr vs. 2.6 mins/hr; 60s: 8.0 mins/hr vs. 1.27 mins/hr) and total physical activity (15s: 31.7 mins/hr vs. 22.3 mins/hr; 60s: = 39.4 mins/hr vs. 25.2 mins/hr) in comparison to Actical accelerometers. These results highlight the present accelerometry-related issues with interpretation of datasets derived from different monitors