Effectiveness of a new service delivery model for management of knee osteoarthritis in primary care: a cluster randomised controlled trial

Objective: Evaluate the effectiveness and health costs of a new primary care service delivery model (PARTNER) to improve health outcomes for people with knee osteoarthritis (OA), compared to usual care. 

Methods: A two-arm, cluster, superiority randomised controlled trial with randomisation at the general practice level, undertaken in Victoria and New South Wales, Australia. We aimed to recruit 44 practices and 572 patients aged ≥45 years with knee pain for >3 months. Professional development opportunities on best-practice OA care were provided to intervention group GPs. All recruited patients had an initial GP visit to confirm knee OA diagnosis. Control patients continued usual GP care and intervention patients were referred to a centralised Care Support Team (CST), for 12-months. Via telehealth, the CST provided OA education and an agreed OA action plan focused on muscle strengthening, physical activity, and weight-management. Primary outcomes were patient self-reported change in knee pain (numerical rating scale, 0-10=worse) and physical function (KOOS Activities of Daily Living subscale, 0-100=better), at 12-months. Healthcare costs outcomes included costs of medical visits and prescription medications over the 12-month period. 

Results: Recruitment targets were not reached. 38 practices and 217 patients were recruited. The intervention improved pain by 0.8/10 points (95% CI 0.2 to 1.4), and function by 6.5/100 points (95% CI 2.3 to 10.7), more than usual care at 12-months. Total costs of medical visits and prescriptions were $3,940 for the intervention group versus $4,161 for usual care. This difference was not statistically significant. 

Conclusion: The PARTNER model improved knee pain and function more than usual GP care. The magnitude of improvement is unlikely to be clinically meaningful for pain but is uncertain for function.