Community Health and Demographic Surveillance System for Noncommunicable Disease Epidemiology Among Adults in Rural and Urban Zimbabwe, 2024-2029: Protocol for a Longitudinal Surveillance Study.

Background: Zimbabwe currently faces a rapidly escalating burden of noncommunicable diseases (NCDs) concurrently with persistent communicable disease challenges, resulting in profound epidemiological differences between rural and urban populations. To effectively address this evolving epidemiological landscape and guide evidence-based public health interventions, reliable and high-quality longitudinal data are essential for capturing temporal shifts and contextual determinants often overlooked by conventional health information systems. Objective: This protocol details the methodology for establishing a health and demographic surveillance system (HDSS), a longitudinal, population-based cohort designed to continuously monitor the prevalence, incidence, and key determinants of NCDs, specifically cardiovascular diseases and diabetes, and their associated risk factors in selected rural (Mt Darwin) and urban (Bindura) sites in Mashonaland Central Province over a 5-year period (2024-2029). Methods: The HDSS uses a stratified multistage sampling design to recruit adults (aged ≥18 y) residing across 2 rural and 2 urban wards. Initial activities include comprehensive community profiling and household mapping, followed by a rigorous baseline survey, with systematic follow-ups scheduled every year. Data encompass essential domains such as vital events, migration patterns, detailed social determinants of health, health behaviors, self-reported and clinically assessed NCDs, physical examinations (including height, weight, blood pressure, and waist/hip circumference), biochemical markers (fasting glucose, lipid profiles, and urine sodium/creatinine), and standardized verbal autopsies. Data capture will make use of REDCap (Research Electronic Data Capture) to facilitate real-time data entry and validation. The protocol is underpinned by rigorous quality assurance procedures, continuous community engagement, and comprehensive ethical oversight. Results: The Zimbabwe HDSS received ethical approval on July 30, 2024 (MRCZ/A/3191). Baseline data collection was completed in Mt Darwin (rural site) in December 2024 and in Bindura (urban site) in March 2025. Statistical analysis of baseline NCD prevalence, risk factor distributions, and rural-urban comparisons is underway, with findings expected to be submitted for publication by the end of 2026. The first annual longitudinal follow-up round is planned for the second quarter of 2027, subject to funding availability, with subsequent rounds scheduled annually through 2029. Longitudinal incidence estimates and NCD trend analyses are expected to be published progressively from 2026 to 2029. Conclusions: This community HDSS addresses a critical evidence deficit within Zimbabwe's national health information infrastructure. By implementing an ethical, sustainable, and community-engaged research methodology, the HDSS serves as a potent regional model. It is designed to generate actionable, policy-relevant data for national health authorities and stakeholders, thereby accelerating the country's NCD prevention and control agenda while simultaneously acting as an enduring platform for academic innovation, capacity building, and policy translation efforts targeting both rural and urban health disparities.