The ActiGraph counts processing and the assessment of vigorous activity
Brønd, 2019

Description

A total of six sets of cut-points were generated using linear regression (four sets) or receiver operating characteristics (ROC) analysis (two sets) for children wearing an ActiGraph on the right hip. Instead of the proprietary counts output by ActiLife software, these cut-points are derived for counts generated using Brønd’s (2017) open-source method using three different band pass filters (AG: 0.29 to 1.66 Hz, AC4: 0.29 to 4 Hz, AC10: 0.29 to 10 Hz). Coefficient of determination (R2) was 0.61 to 0.89 for the linear regression cut-points and sensitivity and specificity ranged from 73.4 to 100.0% and 85.6 to 100.0%, respectively, for the ROC cut-points.

Development/Validation

Sample: 36 3rd-4th grade children in the calibration portion

Setting: Inside and outside of school

Activities: Bicycling, overground/self-paced walking and running, playground activity, sports, stationary

Criterion: MetaMax 3b (VO2)

Accelerometer(s): ActiGraph GT3X+ on right hip

Validation approach: Comparison to criterion

Phase Designation

(What's this?)

This model is in Phase 0 and 2.

Instructions

Counts can be calculated using Brønd’s method (2017) described in a previous paper for which there is code available on GitHub or an R package called activityCounts. Activity intensity can then be calculated for each epoch using these cut-points. Sedentary cut-points were 115, 576 and 768 counts/min for AG, AC4, AC10 (the three band pass filter ranges). Moderate and vigorous cut-points are listed below. The cut-points with the prefix ‘REG’ were developed using linear regression while those with the prefix ‘ROC’ were developed using ROC analysis.

Source Information

Reference:

Brønd, J. C., Aadland, E., Andersen, L. B., Resaland, G. K., Andersen, S. A., & Arvidsson, D. (2019). The ActiGraph counts processing and the assessment of vigorous activity. Clinical Physiology and Functional Imaging, 39(4), 276-283. https://doi.org/10.1111/cpf.12571 Link to Paper

Corresponding author: Jan Brønd, brond@health.sdu.dk

Contact

Kimberly Clevenger at accelerometerrepository@gmail.com