Exercise Self-Efficacy and patient global assessment were associated with 6-min walk test distance in persons with rheumatoid arthritis.

INTRODUCTION: Low functional capacity is related to future loss of daily function and cardiovascular events. The present study explored the associations of patient-reported outcome measures (PROMs) and disease-specific measures with functional capacity as measured by the 6-min walk test (6MWT) in persons with rheumatoid arthritis (RA). METHODS: Seventy-nine participants from rheumatology outpatient clinics were included. The distance walked during the 6MWT (6MWD) was the dependent variable in multivariable regression analyses. Model 1 included the independent variables sex, age (in tertiles to improve model fit), and body mass index (BMI). Building on Model 1, Model 2 added smoking, patient global assessment (PGA), Exercise Self-Efficacy, Hospital Anxiety and Depression Scale's Depression score, and Cohen's Perceived Stress Scale score, whereas Model 3 added smoking, disease duration, present use of glucocorticosteroids, seropositivity, Disease Activity Score 28-C-Reactive Protein (DAS28-CRP), and a comorbidity variable. RESULTS: Median age was 65 years, 76% were female, and median 6MWD was 493 m. In Model 1, BMI and age were significantly associated with the 6MWD (R2 = 0.42). In Model 2, PGA and Exercise Self-Efficacy were also significantly associated with the 6MWD, with standardized regression coefficients of - 0.21 (p = 0.03) and 0.26 (p = 0.004) respectively (R2 = 0.54). The RA-specific variables in Model 3 were not significantly associated with the 6MWD (R2 = 0.49). CONCLUSION: The PROMs PGA and Exercise Self-Efficacy were significantly associated with functional capacity as measured by the 6MWT in persons with RA, whereas disease-specific measures such as DAS28-CRP and disease duration were not. Key Points • Functional capacity measured with the 6-minute walk test was significantly associated with body mass index, age, patient global assessment, and Exercise Self-Efficacy in persons with RA. • Patient-reported outcome measures explained more of the variation in functional capacity than objective or composite measures of disease and are relevant measures in clinical follow-up. • Techniques that enhance self-efficacy for exercise should be incorporated into clinical practice to promote physical activity.