Group physical therapy for veterans with knee osteoarthritis: study design and methodology

Physical therapy (PT) is a key component of treatment for knee osteoarthritis (OA) and can decrease pain and improve function. Given the expected rise in prevalence of knee OA and the associated demand for treatment, there is a need for models of care that cost-effectively extend PT services for patients with this condition. This manuscript describes a randomized clinical trial of a group-based physical therapy program that can potentially extend services to more patients with knee OA, providing a greater number of sessions per patient, at lower staffing costs compared to traditional individual PT. Participants with symptomatic knee OA (n = 376) are randomized to either a 12-week group-based PT program (six 1 h sessions, eight patients per group, led by a physical therapist and physical therapist assistant) or usual PT care (two individual visits with a physical therapist). Participants in both PT arms receive instruction in an exercise program, information on joint care and protection, and individual consultations with a physical therapist to address specific functional and therapeutic needs. The primary outcome is the Western Ontario and McMasters Universities Osteoarthritis Index (self-reported pain, stiffness, and function), and the secondary outcome is the Short Physical Performance Test Protocol (objective physical function). Outcomes are assessed at baseline and 12-week follow-up, and the primary outcome is also assessed via telephone at 24-week follow-up to examine sustainability of effects. Linear mixed models will be used to compare outcomes for the two study arms. An economic cost analysis of the PT interventions will also be conducted.