Protocol for a mixed methods realist evaluation of regional District Health Board groupings in New Zealand.

introductionAchieving effective integration of healthcare across primary, secondary and tertiary care is a key goal of the New Zealand (NZ) Health Strategy. NZ's regional District Health Board (DHB) groupings are fundamental to delivering integration, bringing the country's 20 DHBs together into four groups to collaboratively plan, fund and deliver health services within their defined geographical regions. This research aims to examine how, for whom and in what circumstances the regional DHB groupings work to improve health service integration, healthcare quality, health outcomes and health equity, particularly for Māori and Pacific peoples. METHODS AND ANALYSIS: This research uses a mixed methods realist evaluation design. It comprises three linked studies: (1) formulating initial programme theory (IPT) through developing programme logic models to describe regional DHB working; (2) empirically testing IPT through both a qualitative process evaluation of regional DHB working using a case study design; and (3) a quantitative analysis of the impact that DHB regional groupings may have on service integration, health outcomes, health equity and costs. The findings of these three studies will allow refinement of the IPT and should lead to a programme theory which will explain how, for whom and in what circumstances regional DHB groupings improve service integration, health outcomes and health equity in NZ. ETHICS AND DISSEMINATION: The University of Otago Human Ethics Committee has approved this study. The embedding of a clinician researcher within a participating regional DHB grouping has facilitated research coproduction, the research has been jointly conceived and designed and will be jointly evaluated and disseminated by researchers and practitioners. Uptake of the research findings by other key groups including policymakers, Māori providers and communities and Pacific providers and communities will be supported through key strategic relationships and dissemination activities. Academic dissemination will occur through publication and conference presentations.