Physical activity measurements affected participants' behavior in a randomized controlled trial

van Sluijs, Esther M. F., van Poppel, Mireille N. M., Twisk, Jos W. R. and van Mechelen, Willem (2006) Physical activity measurements affected participants' behavior in a randomized controlled trial. Journal of Clinical Epidemiology, 59 4: 404-411. doi:10.1016/j.jclinepi.2005.08.016

Author van Sluijs, Esther M. F.
van Poppel, Mireille N. M.
Twisk, Jos W. R.
van Mechelen, Willem
Title Physical activity measurements affected participants' behavior in a randomized controlled trial
Journal name Journal of Clinical Epidemiology   Check publisher's open access policy
ISSN 0895-4356
Publication date 2006-04-01
Sub-type Article (original research)
DOI 10.1016/j.jclinepi.2005.08.016
Open Access Status
Volume 59
Issue 4
Start page 404
End page 411
Total pages 8
Place of publication United States
Publisher Elsevier
Language eng
Subject 1117 Public Health and Health Services
Formatted abstract
Background and Objective
Assessing levels and determinants of physical activity as outcome measurements might have an independent effect on participant's physical activity behavior. The objective is to study this effect in a randomized controlled trial (RCT) promoting regular physical activity in Dutch general practice.

Using a Solomon four-group design, participants were randomized twice. After randomization to a control or intervention-condition at general practice level (N = 29), participants were randomized to a group participating in measurements at baseline, 2 and 6 months (3M-group, N = 361), or a group only participating in measurements at 6 months (1M-group, N = 356). Outcome measures assessed at 6 months included: level of physical activity (self-reported and objectively measured with accelerometry), meeting ACSM/CDC guideline for regular physical activity, stage of change, and determinants of physical activity.

Follow-up data on 635 participants (89%) was collected. Statistically significant measurement effects were found for meeting the ACSM/CDC guideline (self-reported), self-efficacy for resisting relapse, knowledge, and on awareness. Other outcome measures showed positive trends, except stages of change.

Measurements of physical activity affect participant's physical activity behavior, possibly triggered by a raised awareness about their own physical activity level. Implications for future research are discussed, as well as methodologic limitations of the study design.
Keyword Physical activity
Randomized controlled trial
Health promotion
General practice
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Human Movement and Nutrition Sciences Publications
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Created: Fri, 03 Apr 2009, 23:58:38 EST by Jason Parr on behalf of School of Human Movement and Nutrition Sciences