Protocol for developing a core outcome set for medicines safety at transitions of care: a systematic review, qualitative study and Delphi consensus.

Introduction: Medication-related problems at transitions of care are common and can lead to patient harm. Comparing results of studies that look at medication reconciliation and medication safety at transitions of care can be difficult as the outcomes reported in these studies are heterogeneous. Moreover, the outcomes measured often lack the patient's perspective. A core outcome set (COS) is a list of outcomes which should be measured and reported in studies in order to avoid heterogeneity between trials, measure outcomes relevant to stakeholders and ensure all trials report usable information. This study aims to develop a COS for medicines safety at transitions of care, through updating an existing systematic review and evaluating the perspectives of patients, carers and healthcare professionals.

Methods: This study is registered with the Core Outcome Measures in Effective Trials (COMET) initiative and the project will be conducted following the COS-STAR (Core Outcome Set-Standards for Reporting) guidelines for the design and reporting of COSs. A four-step process will be followed: (1) updating an existing systematic literature review; (2) semistructured interviews with patients and their caregivers; (3) Delphi survey preparation involving a project steering group to compile a list of potential outcomes; (4) a three-round Delphi consensus exercise involving patients, clinicians and policymakers to refine the final core list of outcomes.

Analysis: This will be the first COS for medicines safety at transitions of care and will address an unmet need in providing an essential measurement approach that incorporates patients', carers' and healthcare professionals' views. The findings apply to both quality improvement and research, ensuring the relevance and translation of future research findings.

Ethics And Dissemination: Ethical approval for the qualitative surveys and Delphi technique has been granted by the Irish College of General Practitioners Research Ethics Committee (Record ID: 2182). The findings of this project will be disseminated through peer-reviewed publications, conference presentations and registration with the COMET Initiative. Members of the Delphi panel will receive summaries of the outputs, and findings will also be shared with the patient and public involvement groups involved in the study through lay summaries. Engagement with professional societies, healthcare organisations and patient groups will ensure that the COS is widely accessible and adopted into future practice.