Core outcome sets in women’s and newborn health: A review, methodological and reporting quality assessment informing recommendations for core outcome set developers and wider stakeholders

Background: Methodological and reporting assessment tools have been developed which allow us to investigate the core outcome set development process Objective: To characterise core outcome sets relevant to women’s and newborn health and assess methodological and reporting quality. Search Strategy: Systematic search using the Core Outcome Measures in Effectiveness Trials (COMET) and the Core Outcomes in Women’s and Newborn Health (CROWN) Initiative databases from inception to March 2020. Selection Criteria: Registered, progressing, and completed core outcome sets. Data Collection and analysis: Descriptive summaries of characteristics and results. Published protocols were assessed using the Core Outcome Set-STAndardised Protocol Items (COS-STAP). Completed core outcome sets were evaluated using COS-STAD (standards for development) and COS-STAR (standards for reporting). Main Results: Eighty studies were identified. Twenty-four studies had published a protocol; four (17%) met all COS-STAP criteria. This was primarily due to poorly defined steering groups and lack of discussion around the potential impact of attrition. Thirty-nine systematic reviews characterized inconsistency in outcome reporting. Twenty studies published a core outcome set development process with four (20%) and three (15%) meeting COS-STAD and COS-STAR recommendations respectively, largely due to variation in patient involvement, outcome selection and the Delphi process Conclusions: Future core outcome set developers should actively engage with the methodological and reporting criteria to enhance the quality of their studies. Clarity is also required within the assessment guidelines as to how these issues should be adequately addressed. We have identified 5 key areas for improvement for future core outcome set developers and wider stakeholders