High self-efficacy - a predictor of reduced pain and higher levels of physical activity among patients with osteoarthritis: an observational study.

BACKGROUND Self-efficacy is considered a core component in self-management. However, there is a lack of knowledge about the association between self-efficacy and health-related outcomes in osteoarthritis. The aim of this study was to investigate whether self-efficacy at baseline was associated with change over time in pain and physical activity after a supported osteoarthritis self-management programme. METHODS A total of 3266 patients with hip or knee osteoarthritis attended this observational, register-based study. Self-efficacy was assessed using the Arthritis Self-Efficacy Scale. Pain was estimated on a visual analogue scale and physical activity by self-reporting number of days per week the patients were physically active ≥30 min. Data were self-reported at baseline and at follow-ups after 3 and 12 months. Analyses were performed using a mixed linear model analysis and are presented with an unadjusted and an adjusted model. RESULTS High vs low self-efficacy for pain management at baseline resulted in reduced pain and increased physical activity at the follow-ups; least squares means and standard error were 37.43 ± 0.40 vs 44.26 ± 0.40, for pain, and 5.05 ± 0.07 vs 4.90 ± 0.08 for physical activity. High self-efficacy for management of other symptoms resulted in lower pain and higher physical activity at follow-up: 35.78 ± 0.71 vs 41.76 ± 0.71 for pain, and 5.08 ± 0.05 vs 4.72 ± 0.05 for physical activity. Patients with obesity reported lower activity levels at the follow-ups. CONCLUSION Self-efficacy at baseline was associated with change over time in pain and physical activity at 3 and 12 months after the supported osteoarthritis self-management programme. High self-efficacy had a positive effect on pain and physical activity, indicating the need for exploring and strengthening patients' self-efficacy. Patients with obesity may need further interventions and support during a self-management programme to achieve an increase in physical activity.