Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1083323 | Journal of Clinical Epidemiology | 2006 | 8 Pages |
Background and ObjectiveAssessing 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.MethodsUsing 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.ResultsFollow-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.ConclusionMeasurements 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.