Protocol for the development of a core outcome set for the evaluation of shared decision-making interventions in healthcare

IntroductionShared decision-making (SDM) is a process whereby patients are supported to reach decisions about their healthcare in collaboration with healthcare professionals. International policy and clinical guidelines highlight the ethical imperative of SDM and recommend SDM for many healthcare decisions and contexts. However, despite decades of SDM research, the impact of implementing SDM interventions within health care remains uncertain. High-quality health technology assessment (HTA) requires an understanding of how interventions to facilitate the adoption and implementation of SDM (e.g., through the use of patient decision aids, decision coaching, question prompt lists, training and feedback, or service changes) impact clinical and health service outcomes. Yet, synthesis of the existing literature is hindered by substantial heterogeneity in the evaluation of interventions to facilitate SDM. A core outcome set (COS) is an agreed standardised set of outcomes that should be measured and reported in all effectiveness studies. There is a COS for SDM in the context of rheumatology (rheuCOS-SDM), designed for use in research studies (e.g., clinical trials or observational studies) evaluating the impact of SDM interventions on clinical outcomes for patients. It is unclear, however, whether the outcome domains identified within a rheumatology context are relevant, comprehensive, or comprehensible when applied to a variety of SDM interventions tailored to and interacting with a range of patient populations, healthcare settings and contexts. The aim of this study is to develop a generic COS for evaluating the impact of SDM interventions on various outcomes. Outcomes for consideration may include assessments of the behaviours and experiences of patients, important others (e.g., carers or relatives) and health professionals, the dynamics within patient-professional interactions, health outcomes for individuals and for the wider population, and the cost-effectiveness of care. The broad scope of the COS will ensure its applicability and utility within diverse healthcare contexts and enable the synthesis of evidence to draw clear conclusions about the impact of SDM interventions, to influence healthcare policy. We define this new, comprehensive COS as the COS-SDM. Methods and AnalysisThrough engagement with key interest holders (including patients and members of the public, clinicians and academics), we agreed on the scope of the COS and to adhere to the Core Outcome Measures in Effectiveness Trials (COMET) handbook and Core Outcome Set-STAndards for Development (COS-STAD) guidelines. This will involve production of a long (comprehensive) list of candidate outcome domains (using evidence synthesis, a COS developed in the context of Rheumatology, and qualitative interviews with interest holders internationally), prioritisation of a short (refined) list of core outcome domains (utilising a sequential two-round international online Delphi), and reaching consensus on the final outcome set (through international meetings, applying modified nominal group techniques and predefined criteria for agreement). Ethics and DisseminationResearch ethics approval has been granted in the UK (University of Bristol Faculty Ethics Committee, ref: 7741; University of Exeter Faculty Ethics Committee, ref: 8207624). The final COS will be disseminated by presentation at international conferences and publication in a peer-reviewed journal. Further dissemination is planned through our patient/public advisory group, professional networks, and executive group channels, to publicise the COS to patient groups, funders, journal editors, international regulatory bodies and HTA boards. RegistrationThis project has been registered in the COMET database (www.comet-initiative.org/Studies/Details/3586).