OBJECTIVES: To determine common domains across existing musculoskeletal core outcome sets (COSs). Secondary aims were to assess the development quality of existing musculoskeletal COSs and whether development quality and patient participation was associated with domain selection. STUDY DESIGN AND SETTING: A systematic review of musculoskeletal COSs. We searched six databases from inception until December 2023. Studies were included if they reported on the development of a COS in adults with musculoskeletal conditions for any type of intervention. Quality was assessed using the Core Outcome Set-Standards for Development recommendations (COS-STAD). Data extracted included scope of the COS, health condition, interventions, and outcome domains. We defined a common core domain when present in >
66% of all COSs. Analyses were performed using descriptive statistics. RESULTS: We included 51 studies reporting on 40 COSs, 25 were developed for research settings only, five for clinical settings only, and 10 for both. We identified 310 domains consisting of 255 mandatory or compulsory or not specified, 45 important, and 10 for further research. Pain (90%) and physical function (88%) were common core domains. COS development quality varied (range: 4-11 recommendations met)
six COS met all standards. Domain definitions were provided in 13 COSs, 27 included patients or representatives in their development process, while nine met all recommendations for the consensus process. COSs involving patients were of higher quality (median: nine vs five for those not involving patients). CONCLUSION: Pain and physical function core domains should be considered for inclusion in all new musculoskeletal COSs. Developers should follow COS development recommendations and include patients or their representatives.