Background Patients with osteoarthritis (OA) and rheumatoid arthritis (RA) have known low levels of physical activity despite the known benefits that exercise provides. Exercise participation in psoriatic arthritis (PsA) cohorts has not been established but due to the unique clinical features of PsA (eg. Enthesitis and psoriasis) there may be additional barriers to exercise participation. This study aims to explore which factors influence exercise participation in patients with PsA compared to RA and OA cohorts.
Methods Patients with a clinical diagnosis of PsA, RA or OA were recruited prospectively at two tertiary hospital rheumatology clinics over 12 months. Demographic data was collected in all patients. Patients completed three questionnaires: a multi-dimensional health assessment questionnaire, the international physical activity questionnaire short form and the self-efficacy for exercise (SEE). Clinical data including joint count, body mass index and co-morbidities including fibromyalgia were collected for all patients. PsA specific data including skin and enthesitis indices were collected in the PsA cohort.
Findings 205 patients (PsA n=62, RA n=83, OA n=60) were recruited across two sites. There was no significant difference in self-reported physical activity between OA, RA and PsA cohorts. Fibromyalgia was present in 30% of each cohort. Self-efficacy for exercise, level of education and patient reported global, pain and function (RAPID-3 score) were significantly associated with levels of self-reported exercise in a multivariable regression model applied across all arthritis cohorts. In a subgroup analysis on patients with PsA, univariate analysis showed that co-existent fibromyalgia, age and self-efficacy for exercise were predictors of self-reported physical activity levels, with multivariable analysis showing age as the only significant predictor or self-reported physical activity. Skin disease and enthesitis were not predictors of physical activity in the PsA cohort.
Conclusions There were no disease specific clinical features of psoriatic arthritis that predicted self-reported physical activity levels in this cohort. This study confirms the role of self-efficacy in predicting self-reported physical activity in arthritis patients.