Everything you wanted to know about selecting the "right" Actigraph accelerometer cut-points for youth, but…: a systematic review.
OBJECTIVE
The purpose of this study is to provide an overview of the evidence on the calibration of ActiGraph accelerometers to quantify moderate-to-vigorous physical activity (MVPA) for youth through the use of cut-points and describe the independent validation studies comparing the accuracy of the developed cut-points to a criterion measure.


METHODS
A systematic review.


METHODS
Studies were identified that: (a) developed ActiGraph accelerometer cut-points for children and youth (calibration study); or (b) performed an independent validation of already established cut-points (validation study). Both calibration studies and independent validation studies were retrieved through a systematic search of online databases. According to proposed guidelines for designing accelerometer calibration studies, each calibration study was evaluated on the following criteria: quality of a criterion measure employed; epoch length; inclusion of a variety of activities; and sample size.


RESULTS
A total of 11 calibration studies were identified. Two studies met all four criteria for a calibration study. A total of 4 independent validation studies were identified. Three of them reported that no cut-points accurately classified moderate-to-vigorous physical activity (MVPA) across all ranges of physical activity intensity levels in comparison to a criterion measure. The fourth study reported two sets of cut-points that under laboratory conditions, accurately classified moderate-to-vigorous physical activity (MVPA) compared to indirect calorimetry.


CONCLUSIONS
Limited evidence suggests that two sets of cut-points correctly classify ActiGraph counts into moderate-to-vigorous physical activity (MVPA). However, limitations with calibration and validation studies indicate greater efforts aimed at designing high quality studies are needed to confirm these findings.
Department of Exercise Science, University of South Carolina, USA. myungshingo@gmail.com
Youngwon
Y
Kim
Michael W
MW
Beets
Gregory J
GJ
Welk
D000054:Acceleration; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D009043:Motor Activity; D054928:Validation Studies as Topic