Study Protocol of a Korean Patient-Centered Shared Decision-Making Model for Management of Severe Knee Osteoarthritis: A Multicenter Pragmatic Clinical Trial (K-SDM-KOA).

Severe knee osteoarthritis (KOA) involves complex, preference-sensitive treatment decisions, ranging from non-operative to surgical options. However, despite the preference-sensitive nature of KOA, existing shared decision-making (SDM) processes often lack clarity in effectively incorporating patients' values and preferences into treatment decisions. Moreover, most SDM models have been developed in western contexts, which may limit their applicability in other cultural settings. To address these limitations, a Korean Shared Decision-Making Model for KOA (K-SDM-KOA) has been developed using a culturally adapted, five-step framework that integrates a web-based decision-support platform and age-friendly educational media. The K-SDM-KOA model is designed to support preference-sensitive decision-making through a pragmatic, multicenter cohort framework involving 1,300 patients with Kellgren-Lawrence grade 3-4 across five hospitals. Within this framework, patients receive either standard care or the K-SDM-KOA intervention, which combines pre-consultation preparation (step 1-3) with in-clinic deliberation and decision-making (step 4-5). The primary outcome is patient-perceived SDM measured using the Korean-validated 9-item Shared Decision Making Questionnaire, reported on a 0-100 scale, with higher scores indicating greater SDM. Secondary outcomes include patients' preferred role in decision-making, decisional conflict, decision regret, and knowledge gain related to KOA. Additionally, a nested cohort of 50 patients undergoing contralateral total knee arthroplasty will provide paired analyses of early pain and function (visual analogue scale, Western Ontario and McMaster Universities Osteoarthritis Index, Knee Society Score) at baseline, 3 months, and 12 months. Analyses will follow an intention-to-treat principle and employ linear mixed-effect models and appropriate statistical tests to assess between group differences. This article presents a culturally tailored, technology-supported SDM model designed to enhance decision quality and early patient-reported outcomes in severe KOA. Findings may provide a foundation for future empirical studies and support the broader adoption of structured SDM in Korea's healthcare system.