Group-based versus individual-based exercise therapy in patients with knee osteoarthritis: study protocol for a non-inferiority randomized controlled trial

Background Knee osteoarthritis (KOA) is one of the most prevalent health issues, affecting approximately 67% of women over 60 years old. Clinical guidelines recommend individualized muscle training to treat this condition. However, a lack of human and financial resources hinders the delivery of this treatment. In response to this limitation, group training may be an alternative. Nevertheless, there are no studies aiming to compare the effectiveness of group training to individual training. Therefore, this study aims to compare the non-inferiority of a group-delivered muscle training program to the same individually delivered training in clinical and functional aspects in elderly women with KOA. Methods This is a randomized controlled non-inferiority trial with two arms, parallel groups, blinded evaluator, conducted in Petrolina - PE, evaluating women aged 60 or older. Participants randomly assigned will undergo an eight-week training, either in individual sessions (Control Group - IB) or as part of a group (Intervention Group - GB) of four participants, supervised by a physical therapist. Blind assessments at baseline, immediately post-intervention, and four weeks post-intervention will include feasibility, safety, and satisfaction analysis of the training program; pain; quality of life; and physical function. Data will be analyzed using the Statistical Package for Social Sciences (SPSS) version 22. Estimated marginal means of each clinical and functional outcome for both groups (IB and GB) will be compared using mixed-effects generalized linear models. The primary analysis will test our main hypothesis that group training is non-inferior to individualized training regarding the primary outcome: relative reduction (%) in the WOMAC questionnaire pain subscale. Confidence intervals of 95% will be calculated. A significance level of p < 0.05 will be adopted in all analyses. Discussion Expected results suggest that a group-based approach is not inferior to an individual one in this population. Trial registration; Brazilian Registry of Clinical Trials (ReBEC) ID: RBR-5bq9jh3. Registered on 18 August 2023. Link: http://www.ensaiosclinicos.gov.br; Universal Trial Number (UTN) of World Health Organization: U1111-1289-2580.