Estimating health benefits of a peri-urban railway: A quantitative health impact assessment focused on diabetes

Transport is a significant determinant of health. This study investigates the potential health benefits of introducing a commuter railway line to a rapidly growing peri-urban area in South West Sydney. We focus on diabetes, a condition with high regional prevalence. The rationale is to assess how infrastructure development can influence public health outcomes, particularly in areas with low active transport rates and high car dependency. A quantitative Health Impact Assessment (HIA) was conducted using the DYNAMO-HIA modelling tool. This tool utilises a partial micro-simulation multi-state model to estimate changes in disease burden and life expectancy. Two scenarios were simulated over an 11-year period (2019–2029): a baseline scenario with no intervention and an intervention scenario involving the introduction of a commuter rail line. The intervention was expected to increase walking and reduce diabetes burden. Data inputs included population demographics, walking prevalence, and diabetes incidence and mortality. The intervention scenario showed an annual reduction in diabetes incidence and prevalence of approximately 0.02%. Life expectancy increased by about one month, and a total of 222 Disability-Adjusted Life Years (DALYs) were gained due to reduced diabetes burden. Although these numbers may appear modest, they represent meaningful health gains for a small and rapidly growing community, underscoring the significant impact that even incremental improvements can achieve at this scale. The study demonstrates the feasibility of applying predictive modelling tools in HIA for infrastructure planning. It highlights the importance of integrating health considerations into urban development, especially in peri-urban contexts. Although limited to one disease and intervention, the findings support evidence-based planning for healthier communities.