Core outcome sets developed for research relevant to physiotherapy interventions: a systematic review

Abstract Background A Core Outcome Set (COS), defined as the agreed minimum set of outcomes to be measured and reported in all clinical trials for a particular condition, could help address outcome heterogeneity across studies and lack of consideration of what matters to patients. This study aimed to identify all COS developed for research relevant to physiotherapy interventions, evaluate whether their development met minimum standards, and classify the recommended outcomes to provide a reference point for future comparisons. Methods The COMET database was searched to identify relevant published and ongoing COS related to physiotherapy interventions. Two investigators independently screened the articles for inclusion, followed by independent data extraction of included COS and evaluation of the COS according to the Core Outcome Set-STAndards for Development (COS-STAD). For each included COS, the core outcomes were categorised using the COMET taxonomy. Results The scope of the COS was specified in all the included studies (N = 31), with most COS applicable to rheumatological conditions and physical rehabilitation interventions. Around 40% (n = 13) were developed with participation from more than one region of the world. Patients participated in the development process in two thirds of COS studies (n = 21, 68%) with health care professionals participating in almost all included studies (n = 30, 97%). Aspects of the consensus process were decided a priori in 26% (n = 8, for consensus definition and criteria for including, dropping or adding outcomes) and 32% (n = 10, for scoring process) of studies. All COS included at least one life impact outcome, and emotional functioning outcomes were more prominent in COS that included patient input. Conclusion This review highlights the need for improvement in the development of COS, particularly in relation to increasing global involvement, patient participation, and reporting of the consensus process during COS development. Systematic review registration number: PROSPERO CRD42025620018