Cluster randomised controlled trial for service delivery redesign of primary care for people with diabetes: study protocol.

introductionStrong primary healthcare enhances resource efficiency and resilience. Type 2 diabetes poses a growing global health challenge, with Argentina's healthcare system struggling to detect and manage the disease effectively. Many patients bypass primary healthcare for secondary facilities, undermining continuity of care and increasing costs. Following a diagnostic process in collaboration with policymakers, we propose evaluating a redesigned primary care model consisting of codesigned evidence-based implementation strategies to improve type 2 diabetes management in Mendoza, Argentina. METHODS AND ANALYSIS: This is an efficient, parallel-arm cluster randomised controlled Hybrid Type II trial with 12 clusters (administrative areas with 2-3 health facilities) allocated 1:1 to control (usual care) or intervention. In phase I, we will codesign, pilot and refine an implementation strategy package. In phase II, we will conduct the trial: 9-month baseline data collection, 15-month intervention and 6-month sustainability period. We will enrol a cohort of 396 patients with type 2 diabetes at primary healthcare centres and follow them for 12 months during the intervention and 6 months sustainment using routine clinical records and patient surveys. In phase III, we will conduct analysis, report and disseminate findings. The primary outcome will be a composite outcome including glycaemic control (glycated haemoglobin (HbA1c) <8%); blood pressure control (<140/90 mm Hg) and statin prescription (limited to patients ≥40 years) from clinical records. The primary analysis will compare the proportion of patients achieving this composite clinical outcome between the trial arms at the end of the study. Secondary analyses include assessing patient experience and primary healthcare engagement; testing the implementation strategies' impact on service use patterns, system competence, user confidence and cost per visit; exploring inequalities by sociodemographic factors; and assessing patient empowerment. We will use all available data from all randomised clusters and conduct all analyses on the intention-to-treat population, regardless of intervention adherence. ETHICS AND DISSEMINATION: All study activities will comply with national and international ethics guidelines, presenting minimal risk to participants. The protocol was submitted and approved by the local independent ethics committee at the Mendoza Ministry of Health (Consejo Provincial de Evaluación ética en investigación en Salud-Provincial Health Research Ethics Review Board, Reference number: 149/2024). Facility-level permission will be obtained for participation and sharing of deidentified data. Written informed consent will be required from study participants, who will receive information on the study's purpose, procedures, risks and benefits. Dissemination activities and outputs will include writing and submitting manuscripts for publication; writing policy briefs to support strategy implementation in other regions or countries; and tailoring outputs for patients, clinicians and researchers. We anticipate that improvements in disease management and patient experience will have clinical and economic benefits related to reduced usage of secondary-level and tertiary-level facilities, lower cost per visit and a reduced number of clinical events related to diabetes. TRIAL REGISTRATION NUMBER: ISRCTN63277390.