Limited effect of a self-management exercise program added to spa therapy for increasing physical activity in patients with knee osteoarthritis: a quasi-randomized controlled trial

Abstract Background. The efficacy of spa therapy in osteoarthritis (OA) has ever been demonstrated, with a good level of evidence for pain and disability. The effect of a self-management program with spa therapy on physical activity (PA) level has never been demonstrated. Objective. This study aimed to assess, at 3 months, the effectiveness of 5 sessions of a self-management exercise program in patients with knee OA (KOA) who benefit from 18 days of spa therapy and received an information booklet (on proposed physical exercises) on improvement in at least one PA level. Methods. This was an interventional, multicentre, quasi-randomized controlled trial with a cluster randomized design (1-month period). People 50 to 75 years old with symptomatic knee OA (KOA) were included in 3 spa therapy centres in France (Bourbon Lancy, Le Mont Dore, Royat). Both groups received conventional spa therapy sessions during 18 days and an information booklet on the benefits of PA practice for KOA. The intervention group additionally received 5 self-management exercise sessions. The main outcome was improvement in at least one PA level according to the International Physical Activity Questionnaire (IPAQ) short-form categorical score (low to moderate or high, or moderate to high) at 3 months. Secondary outcomes were the evolution of PA (MET-min/week), disability, pain, anxiety, depression, self-efficacy, fears and beliefs concerning KOA, barriers to and facilitators of regular PA practice, consumption of painkillers and adherence to physical exercise program at 3 months. Assessors but not participants or caregivers were blinded. Results. In total, 123 patients were randomized, 54 to the intervention group and 69 to the control group. Considering the main outcome, at 3 months, 37% of patients in the intervention group showed improvement in at least one PA level according to the IPAQ categorical score versus 30.4% in the control group (p=0.44). In the intervention group, 13 (24.1%) patients showed improvement from low to moderate PA level (vs 8 [11.6%] in the control group), 2 (3.7%) from low to high (vs 2 [2.9%]) and 5 (9.3%) from moderate to high (vs 11 [15.9%]). Both intervention and control groups showed increased IPAQ continuous scores (MET-min/week) at 3 months, although not significantly. HAD anxiety and depression scores were significantly reduced in the intervention group (p=0.001 and p=0.049, respectively) and the perception of PA was better in the intervention than control group for motivation and barriers scores (p=0.019 and p=0.002, respectively). Conclusions. This study showed the lack of impact of a short self-management program on PA level in addition to 18-day spa therapy for KOA, but both intervention and control groups showed improved PA level.