Patient-reported outcomes in studies evaluating shared decision-making interventions: protocol for a systematic review and meta-analysis.

introductionShared decision-making (SDM) aims to align health decisions with evidence and patients' values, preferences and circumstances. Patient-reported outcomes (PROs) are central to evaluating SDM because many relevant outcomes, including feeling informed, understanding risks, decisional conflict, decisional regret and treatment burden, can be assessed only from the patient's perspective. However, which PROs are used in SDM intervention studies and whether intervention effects vary across PRO constructs remain unclear. This protocol describes a systematic review that will map PROs and synthesise effects by PRO construct, where data permit. METHODS AND ANALYSIS: This systematic review protocol is reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. We will search seven databases-PubMed, Embase, CINAHL, Web of Science Core Collection, Scopus, CENTRAL and PsycINFO-from inception to the date of the final search, supplemented by ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, reference-list screening and forward citation tracking. Randomised and non-randomised comparative studies will be synthesised separately, while single-arm studies will contribute to outcome mapping only. PROs will be defined as outcomes reported or completed directly by patients, while patient-reported SDM process measures will be classified separately. Two reviewers will independently screen titles/abstracts and full texts and extract data. Risk of bias will be assessed independently, using appropriate design-specific tools, for all comparative studies eligible to contribute to effect synthesis. Outcomes will be mapped to prespecified domains. Meta-analysis will be performed where studies are sufficiently comparable; otherwise, narrative synthesis will follow Synthesis Without Meta-analysis guidance. The certainty of evidence will be assessed using the Grading of Recommendations Assessment, Development and Evaluation. ETHICS AND DISSEMINATION: Ethical approval is not required because this review will use non-identifiable aggregate information from existing study reports and trial registries and will not involve primary data collection from human participants or identifiable personal data. Findings will be disseminated through peer-reviewed publications and academic conferences. PROSPERO REGISTRATION NUMBER: CRD420261413222.