Who Makes It to the Base? Selection Procedure for a Physical Activity Trial Targeting People With Rheumatoid Arthritis

Abstract

ObjectiveTo compare those who were finally included in a large well-defined sample of individuals with rheumatoid arthritis (RA) at target for a physical activity (PA) trial with those who were not.MethodsIn total, 3,152 individuals answered questionnaires on sociodemographic, disease-related, and psychosocial factors and PA levels. The differences between individuals making it to the baseline assessments and those who did not were analyzed in 3 steps.ResultsIn a first step, 1,932 individuals were eligible for the trial if they were interested in participating, not physically active enough, and fluent in Swedish and if they were not participating in any other study. The participants were mainly younger women, had higher education and income, were more likely to live with children, and had better support for exercise and had higher outcome expectations of PA than the 1,208 ineligible individuals. In a second step, the 286 individuals accepting participation had higher income and education, more support for exercise, less fear-avoidance beliefs, and higher outcome expectations of PA than the 1,646 individuals declining participation. In a third step, the 244 individuals assessed at baseline reported less fatigue than the 42 withdrawing before assessment.ConclusionTo our knowledge, this is the first study describing the entire selection procedure, from a target sample for a PA trial to the sample assessed at baseline, in individuals with RA. Factors other than those related to the disease seemed to mainly determine participation and largely resembled determinants in the general population. Sociodemographic and psychosocial factors should be recognized as important for PA in people with RA.

Physical activity interventions for fatigue in rheumatoid arthritis: a systematic review

“…These reasons have been cited in other PA trials in RA 44,45 . An in-depth analysis of participants and nonparticipants in a recent PA trial in RA concluded that only 8% of the initial target population…”

“…Participants who withdrew from a recent PA trial between agreeing to take part and baseline assessment reported more fatigue than those who were assessed (p=0.009) 44 . It is possible that eligible patients who experienced greater fatigue declined participation in studies included in this review and the resulting participants might be less representative of fatigued patients with RA.…”

“…PA research relies on voluntary participation. Consequently, recruitment is often biased towards those who are interested in or motivated to perform PA 44 . Self-selection of participants in PA trials also has implications for the control arm.…”

“…were assessed at baseline, despite 62% expressing interest prior to receiving information about location, timing and cost of the PA interventions 44 . It is possible that PA interventions only reach a small minority of eligible participants in clinical practice.…”

“…This includes imbalances in gender, with the inclusion of women only in two studies and fewer men included overall. Although RA affects more women than men 2 , men tend to be under-represented in PA trials in RA 44,48 . Also, men with RA may require different support strategies than women 49 .…”