Header

UZH-Logo

Maintenance Infos

Reactivity to Accelerometer Measurement of Children and Adolescents


Dössegger, Alain; Ruch, Nicole; Jimmy, Gerda; Braun-Fahrländer, Charlotte; Mäder, Urs; Hänggi, Johanna; Hofmann, Heidi; Puder, Jardena J; Kriemler, Susi; Bringolf-Isler, Bettina (2014). Reactivity to Accelerometer Measurement of Children and Adolescents. Medicine and Science in Sports and Exercise, 46(6):1140-1146.

Abstract

PURPOSE: Awareness of being monitored can influence participants' habitual physical activity (PA) behavior. This reactivity effect may threaten the validity of PA assessment. Reports on reactivity when measuring the PA of children and adolescents have been inconsistent. The aim of this study was to investigate whether PA outcomes measured by accelerometer devices differ from measurement day to measurement day, and whether the day of the week and the day on which measurement started influence these differences.
METHODS: Accelerometer data (Counts per minute, cpm) of children and adolescents (n = 2081) pooled from eight studies in Switzerland with at least 10 hours of daily valid recording were investigated for effects of measurement day, day of the week, and start day using mixed linear regression.
RESULTS: The first measurement day was the most active day. Cpm were significantly higher than on the second to the sixth day, but not on the seventh day. Differences in the age-adjusted means between the first and consecutive days ranged from 23 to 45 cpm (3.6-7.1%). In pre-school children, the differences almost reached 10%. The start day significantly influenced PA outcome measures.
CONCLUSION: Reactivity to accelerometer measurement of PA is likely to be present to an extent of about 5% on the first day and may introduce a relevant bias to accelerometer-based studies. In pre-school children, the effects are larger than in elementary and secondary school children. As the day of the week and the start day significantly influence PA estimates, researchers should plan for at least one familiarization day in school-age children and randomly assign start days.

Abstract

PURPOSE: Awareness of being monitored can influence participants' habitual physical activity (PA) behavior. This reactivity effect may threaten the validity of PA assessment. Reports on reactivity when measuring the PA of children and adolescents have been inconsistent. The aim of this study was to investigate whether PA outcomes measured by accelerometer devices differ from measurement day to measurement day, and whether the day of the week and the day on which measurement started influence these differences.
METHODS: Accelerometer data (Counts per minute, cpm) of children and adolescents (n = 2081) pooled from eight studies in Switzerland with at least 10 hours of daily valid recording were investigated for effects of measurement day, day of the week, and start day using mixed linear regression.
RESULTS: The first measurement day was the most active day. Cpm were significantly higher than on the second to the sixth day, but not on the seventh day. Differences in the age-adjusted means between the first and consecutive days ranged from 23 to 45 cpm (3.6-7.1%). In pre-school children, the differences almost reached 10%. The start day significantly influenced PA outcome measures.
CONCLUSION: Reactivity to accelerometer measurement of PA is likely to be present to an extent of about 5% on the first day and may introduce a relevant bias to accelerometer-based studies. In pre-school children, the effects are larger than in elementary and secondary school children. As the day of the week and the start day significantly influence PA estimates, researchers should plan for at least one familiarization day in school-age children and randomly assign start days.

Statistics

Citations

21 citations in Web of Science®
23 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

50 downloads since deposited on 22 Jan 2014
18 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Epidemiology, Biostatistics and Prevention Institute (EBPI)
Dewey Decimal Classification:610 Medicine & health
Language:English
Date:2014
Deposited On:22 Jan 2014 17:06
Last Modified:26 Aug 2017 00:44
Publisher:Lippincott, Williams & Wilkins
ISSN:0195-9131
Additional Information:This is a non-final version of an article published in final form in Dössegger, Alain; Ruch, Nicole; Jimmy, Gerda; Braun-Fahrländer, Charlotte; Mäder, Urs; Hänggi, Johanna; Hofmann, Heidi; Puder, Jardena J; Kriemler, Susi; Bringolf-Isler, Bettina (2013). Reactivity to Accelerometer Measurement of Children and Adolescents. Medicine and Science in Sports and Exercise:Epub ahead of print.
Free access at:PubMed ID. An embargo period may apply.
Publisher DOI:https://doi.org/10.1249/MSS.0000000000000215
PubMed ID:24219978

Download

Download PDF  'Reactivity to Accelerometer Measurement of Children and Adolescents'.
Preview
Content: Accepted Version
Filetype: PDF
Size: 1MB
View at publisher
Download PDF  'Reactivity to Accelerometer Measurement of Children and Adolescents'.
Preview
Content: Published Version
Filetype: PDF
Size: 993kB