Establishing Wrist-Based Cutpoints for the Actical Accelerometer in Elementary School-Aged Children

Background: The wrist has become a standard location for accelerometry (ACC) data collection, primarily to optimize compliance, yet interpretation of wrist ACC data is limited due to a lack of calibration studies. This study aimed to establish cutpoints for a wrist-mounted Actical accelerometer in 6- to 11-year-old children using 2 methods. Methods: Metabolic and ACC data (15-sec epoch) were collected during 8 activities in 22 children ages 6–11. Linear regression (LR) and Receiver Operator Characteristics (ROC) were used to examine the relationship between METs and ACC counts. Cutpoints were established at < 1.5, 1.5–2.99, 3–5.99, and ≥ 6 METs for sedentary, light, moderate, and vigorous activity, respectively. Cutpoints were applied to a large, multiday sample of children (n = 269) to examine differences in cutpoints on minutes of moderate to vigorous PA (MVPA). Results: LR and ROC yielded moderate cutpoints of 574 and 388, respectively. When applied to the large sample, LR and ROC cutpoints resulted in...