Baseline predictors of physical activity in a sample of adults with arthritis participating in a self-directed...

To examine baseline predictors of moderate-to-vigorous intensity physical activity (MVPA) at the 12-week follow-up in a sample of adults with arthritis participating in a self-directed, multicomponent exercise program.

Pretest-posttest. Analyses were limited to those randomized to the exercise intervention.

Participants (n = 152) completed a survey assessing demographic, health-related, and arthritis-related factors, and completed anthropometric and functional measurements at baseline. Self-reported MVPA was assessed at baseline and 12 weeks. Participants were classified as engaging in ≥2.5 or <2.5 h/week of MVPA at the 12-week follow-up. Baseline demographic, health-related, arthritis-related, and functional factors were examined as predictors of engaging in ≥2.5 h of MVPA.

At the 12-week follow-up, 66.5% (n = 101) of participants engaged in ≥2.5 h/week of MVPA. Those with a higher body mass index, more days with poor physical health, a greater number of health conditions, self-reported hypertension, self-reported high cholesterol, and greater pain and stiffness were less likely to engage in ≥2.5 h of MVPA at the 12-week follow-up; those with greater arthritis self-efficacy and better performance on the 6 minute walk test were more likely. None of the other factors examined were associated with MVPA.

This study uncovered health-related, arthritis-related, and functional factors associated with MVPA that may help guide intervention strategies. Participants with less severe symptoms, better functional performance and fewer comorbidities at baseline were more likely to achieve the recommended MVPA level at 12 weeks; therefore self-directed PA interventions may be best suited for those with relatively good health status despite arthritis, while those with worse symptoms and health status may benefit more from other intervention delivery modalities such as structured, individualized programs where additional support for managing arthritis symptoms and comorbidity can be addressed.