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Reproducibility of objectively measured physical activity: Reconsideration needed.

Authors :
Aadland E
Nilsen AKO
Ylvisåker E
Johannessen K
Anderssen SA
Source :
Journal of sports sciences [J Sports Sci] 2020 May; Vol. 38 (10), pp. 1132-1139. Date of Electronic Publication: 2020 Mar 23.
Publication Year :
2020

Abstract

Reliability of accelerometer-determined physical activity (PA), and thus the required length of a monitoring period, appears to depend on the analytic approach used for its calculation. We compared reliability of objectively measured PA using different resolution of data in a sample of 221 Norwegian 2-6-year-old children providing 2-3 valid 14-day periods of accelerometer monitoring (ActiGraph GT3X+) during September-October, January-February, and May-June 2015-2016. Reliability (intra-class correlation [ICC]) was measured for 1-14 days of monitoring across the measurement periods using linear mixed effect modelling. These results were compared to reliability estimated using different resolution of data using the Spearman-Brown formula. The measured reliability improved only marginally with increased monitoring length and levelled off after 5-6 days. Estimated reliability differed substantially when derived from different resolution of data: 3.9-5.4, 6.7-9.2, 13.4-26.7 and 26.3-87.7 days of monitoring was required to achieve an ICC = 0.80 using an hour-by-hour, a day-by-day, a week-by-week and a period-by-period approach, respectively. Reliability could not be correctly estimated from any single resolution of data. We conclude that reconsideration is needed with regard to how reproducibility of objectively measured PA is analysed and interpreted.

Details

Language :
English
ISSN :
1466-447X
Volume :
38
Issue :
10
Database :
MEDLINE
Journal :
Journal of sports sciences
Publication Type :
Academic Journal
Accession number :
32202469
Full Text :
https://doi.org/10.1080/02640414.2020.1743054