posted on 2016-08-03, 15:32authored byAlex V. Rowlands, Dylan P. Cliff, Stuart J. Fairclough, Lynne M. Boddy, Tim S. Olds, Gaynor Parfitt, Rob J. Noonan, Samantha J. Downs, Zoe R. Knowles, Michael W. Beets
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 ≤5 s and 15 s epochs (ICC≥0.69) and ENMO 300+ mg for 60 s epochs (ICC=0.73); Puyau = ENMO 300+ mg for ≤5 s epochs (ICC=0.73), ENMO 350+ mg for 15 s epochs (ICC=0.73), ENMO 400+ mg for 60 s epochs (ICC=0.65). Agreement was robust with cross-validation ICCs=0.62-0.71 and means within |7.8|±4.9% of MVPA estimates from ActiGraph cut-points, except Puyau 60 s epochs (ICC=0.42). CONCLUSION: Incremental ENMO thresholds enable children’s acceleration data measured at the wrist to be simply and directly compared, at a group level, to past estimates of MVPA from hip-worn ActiGraphs across a range of cut-points.
History
Citation
Medicine and Science in Sports and Exercise, 2016, 48 (11), pp. 2142-2149
Author affiliation
/Organisation/COLLEGE OF MEDICINE, BIOLOGICAL SCIENCES AND PSYCHOLOGY/School of Medicine
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