OMERACT Core outcome measurement set for shared decision making in rheumatic and musculoskeletal conditions: a scoping review to identify candidate instruments

Objectives: Shared decision making (SDM) is a central tenet in rheumatic and musculoskeletal care. The lack of standardization regarding SDM instruments and outcomes in clinical trials threatens the comparative effectiveness of interventions. The Outcome Measures in Rheumatology (OMERACT) SDM Working Group is developing a Core Outcome Set for trials of SDM interventions in rheumatology and musculoskeletal health. The working group reached consensus on a Core Outcome Domain Set in 2020. The next step is to develop a Core Outcome Measurement Set through the OMERACT Filter 2.2. Methods: We conducted a scoping review (PRISMA-ScR) to identify candidate instruments for the OMERACT Filter 2.2 We systematically reviewed five databases (Ovid MEDLINE®, Embase, Cochrane Library, CINAHL and Web of Science). An information specialist designed search strategies to identify all measurement instruments used in SDM studies in adults or children living with rheumatic or musculoskeletal diseases or their important others. Paired reviewers independently screened titles, abstracts, and full text articles. We extracted characteristics of all candidate instruments (e.g., measured construct, measurement properties). We classified candidate instruments and summarized evidence gaps with an adapted version of the Summary of Measurement Properties (SOMP) table. Results: We found 14,464 citations, read 239 full text articles, and included 99 eligible studies. We identified 220 potential candidate instruments. The five most used measurement instruments were the Decisional Conflict Scale (traditional and low literacy versions) (n=38), the Hip/Knee-Decision Quality Instrument (n=20), the Decision Regret Scale (n=9), the Preparation for Decision Making Scale (n=8), and the CollaboRATE (n=8). Only 44 candidate instruments (20%) had any measurement properties reported by the included studies. Of these instruments, only 57% matched with at least one of the 7-criteria adapted SOMP table. Conclusion: We identified 220 candidate instruments used in the SDM literature amongst people with rheumatic and musculoskeletal diseases. Our classification of instruments showed evidence gaps and inconsistent reporting of measurement properties. The next steps for the OMERACT SDM Working Group are to match candidate instruments with Core Domains, assess feasibility and review validation studies of measurement instruments in rheumatic diseases or other conditions. Development and validation of new instruments may be required for some Core Domains.