General practitioners ending their practice and impact on patients' health, healthcare use and mortality: a protocol for national registry cohort studies in Norway, 2008 to 2021.

introductionContinuous general practitioner (GP) and patient relations associate with positive health outcomes. Termination of GP practice is unavoidable, while consequences of final breaks in relations are less explored. We will study how an ended GP relation affects patient's healthcare utilisation and mortality compared with patients with a continuous GP relation. METHODS AND ANALYSIS: We link national registries data on individual GP affiliation, sociodemographic characteristics, healthcare use and mortality. From 2008 to 2021, we identify patients whose GP stopped practicing and will compare acute and elective, primary and specialist healthcare use and mortality, with patients whose GP did not stop practicing. We match GP-patient pairs on age and sex (both), immigrant status and education (patients), and number of patients and practice period (GPs). We analyse the outcomes before and after an ended GP-patient relation, using Poisson regression with high-dimensional fixed effects. ETHICS AND DISSEMINATION: This study protocol is part of the approved project Improved Decisions with Causal Inference in Health Services Research, 2016/2159/REK Midt (the Regional Committees for Medical and Health Research Ethics) and does not require consent. HUNT Cloud provides secure data storage and computing. We will report using the STROBE guideline for observational case-control studies and publish in peer-reviewed journals, accessible in NTNU Open and present at scientific conferences. To reach a broader audience, we will summarise articles in the project's web page, regular and social media, and disseminate to relevant stakeholders.