Spatiotemporal Modeling of Premature Mortality in Mississippi: A County-Level Analysis of Years of Potential Life Lost, 2015–2025

Introduction: Understanding premature mortality through years of potential life lost (YPLL) is essential for identifying preventable deaths and health inequities, yet county-level spatiotemporal patterns remain understudied in states such as Mississippi that have high rates of premature mortality. This study examined spatiotemporal trends in premature mortality across Mississippi's 82 counties (2015-2025) using years of potential life lost (YPLL) before age 75 years. Methods: We determined county-level YPLL rates from County Health Rankings & Roadmaps (2015-2025) (underlying deaths from approximately 2012 to 2023). Trends were compared with US averages, stratified by education, income, and insurance status; mapped via GIS; analyzed for spatial clustering with calculated local indicators of spatial association (LISA); and modeled by using spatial autoregressive (SAR) lag models with year fixed effects. Results: From 2015 to 2025, Mississippi's YPLL rate rose 35.2% (10,918.3 to 14,763.9 per 100,000), far outpacing national trends and widening the gap between the state and the US by approximately 50%. Contrary to expectation, the largest increases occurred in high-education, high-income, low-uninsured (mostly urban/coastal) counties. Hot spots intensified in rural Delta and Mississippi River counties, while cold spots disappeared from urban and coastal areas. SAR models showed strong spatial dependence (ρ ≈ 0.32); key drivers were injury-related deaths (β = 58.9, P < .001), percentage of population that is non-Hispanic Black, and diabetes prevalence, while higher median household income was associated with lower YPLL. Conclusion: Mississippi's premature mortality pattern has shifted: rural burdens persist, but rapid deterioration in urban and more affluent counties now drives statewide worsening. Effective policy requires sustained rural investment in chronic disease control along with urban-focused interventions targeting injury and violence prevention, trauma systems, and mental health/substance-use services.