Moving forward with backwards compatibility: Translating wrist accelerometer data

Purpose: To provide a means for calibrating raw acceleration data from wrist-worn accelerometers in relation to past estimates of children’s moderate-to-vigorous physical activity (MVPA) from a range of cut-points applied to hip-worn ActiGraph data. Methods: This is a secondary analysis of three studies with concurrent 7-day accelerometer wear at the wrist (GENEActiv) and hip (ActiGraph) in 238 children aged 9-12 years. The time spent above acceleration (ENMO) thresholds of 100, 150, 200, 250, 300, 350 and 400 mg from wrist acceleration data (<5 s epoch) was calculated for comparison to MVPA estimated from widely used children’s hip-worn ActiGraph MVPA cut-points (Freedson/Trost 1100 counts per minute (cpm); Pate 1680 cpm; Evenson 2296 cpm; Puyau 3200 cpm) with epochs of <5, 15 and 60 s. Results: The optimal ENMO thresholds for alignment with MVPA estimates from ActiGraph cut-points determined from 70% of the sample and cross-validated with the remaining 30% were: Freedson/Trost = ENMO 150+ mg, irrespective of ActiGraph epoch (ICC>0.65); Pate = ENMO 200+ mg, irrespective of ActiGraph epoch (ICC>0.67); Evenson = ENMO 250+ mg for 0.69) and ENMO 300+ mg for 60 s epochs (ICC=0.73); Puyau = ENMO 300+ mg for