Calibration and validation of physical behaviour cut-points using wrist-worn ActiGraphs for children and adolescents: A systematic review

Objectives: To review cut -points calibrated and independently validated from wrist -worn ActiGraph accelerometers to measure moderate to vigorous physical activity (MVPA) and time spent sedentary (SED) in children and adolescents. Design: Systematic literature review. Methods: Five databases were searched for relevant cut -point calibration and independent validation studies relating to wrist worn ActiGraphs in children and adolescents from inception through 30 April 2022. Extracted data included: country of publication; study name; population; device model; wear location; sampling frequency; epoch length; activity protocol; criterion method and definitions used to classify PA intensity; statistical methods for calibration; statistical methods for validation/cross-validation; and MVPA and SED outcome. Results: Fourteen calibration studies and seven independent validation studies were identified. Calibrated cutpoints for MVPA vector magnitude counts ranged from 7065 to 9204 counts per minute (cpm) and 63.5 to 201 milli -gravitational units (mg). For SED, calibrated cut -points ranged from <2556 cpm to 4350 cpm and 30.8 to 48.1 mg. Classification accuracy values determined by independent validation studies varied, with kappa values ranging from 0.31 to 0.60 and area under the curve statistics ranging from 0.51 to 0.84 for MVPA and kappa values ranging from 0.31 to 0.44 and area under the curve statistics ranging from 0.70 to 0.85 for SED. Conclusions: The results of this systematic literature review support the use of the Crouter and colleagues cutpoints for the measurement of MVPA and SED for children and adolescents aged 6-12 years. Further work is required to independently validate cut -points developed in younger children and older adolescents. (c) 2023 The Authors. Published by Elsevier Ltd on behalf of Sports Medicine Australia.