Establishing and evaluating wrist cutpoints for the GENEActiv accelerometer in youth
Schaefer, 2014
Description
Cut-points for classifying physical activity intensity from signal magnitude vector divided by sampling frequency were generated using receiver operating characteristics (ROC) analysis for children wearing GENEActiv monitors on the non-dominant wrist. Sensitivity and specificity ranged from 91 to 97% and 85 to 88%, respectively.
Development/Validation
Sample: 24 children, 6-11 y of age
Setting: Laboratory
Activities: Active video games, stationary, treadmill walking/running
Criterion: Oxycon Mobile (VO2)
Accelerometer(s): GENEActiv on non-dominant wrist
Validation approach: Leave-one-out cross-validation
Instructions
Data were filtered using a bandpass filter with cutoffs of 0.1 and 15 Hz, then signal magnitude vector per 1-sec was calculated as square root of the sum of the squared acceleration in each axis, which was then divided by sampling frequency. Below are the developed cut-points. However, as noted in the R package GGIR, these cut-points are sensitive to sampling rate, so they provide a scaled version which can be applied to any raw acceleration data.
Source Information
Reference:
Schaefer, C. A., Nigg, C. R., Hill, J. O., Brink, L. A., & Browning, R. C. (2014). Establishing and evaluating wrist cutpoints for the GENEActiv accelerometer in youth. Medicine and Science in Sports and Exercise, 46(4), 826. https://doi.org/10.1249%2FMSS.0000000000000150 Link to Paper
Corresponding author: Christine Schaefer, Christine.a.schaefer@gmail.com
Contact
Kimberly Clevenger at accelerometerrepository@gmail.com