Healthcare Deserts and Avoidable Mortality in Mexico: A Municipal-Level Ecological Analysis of Health System Resources, Social Deprivation, and Preventable Deaths, 2015–2024

Background/Objectives: Avoidable mortality—deaths before age 75 from preventable or treatable causes—is a key indicator of health system performance. In Mexico, nearly two-thirds of municipalities lack hospital beds, yet no study has examined the municipal-level association between healthcare infrastructure and avoidable mortality. This study assessed whether healthcare desert status is independently associated with avoidable mortality after adjusting for social deprivation. Methods: This ecological study analyzed 1891 Mexican municipalities (population ≥ 1000) over 2015–2024. Avoidable deaths were classified per OECD/Eurostat criteria (January 2022 revision). Healthcare desert status was defined by municipal hospital bed availability from 2019 facility data. Negative binomial mixed-effects regression estimated incidence-rate ratios (IRRs) adjusted for social deprivation, age structure, and state-level heterogeneity. Interrupted time-series analysis quantified pandemic disruption. Results: Of 4,960,244 deaths under 75 years, 81.2% were avoidable. Of 1891 municipalities, 1187 (62.8%) lacked hospital beds (healthcare deserts). Desert municipalities had 42.5% higher avoidable mortality (IRR = 1.425; 95% CI: 1.370–1.482; pre-pandemic 2015–2019), which attenuated to 1.353 after age-structure adjustment. Each standard-deviation increase in hospital beds (1 SD ≈ 2.2 beds per 1000) was associated with 7.9% lower mortality (IRR = 0.921). Avoidable mortality exhibited strong spatial clustering (Moran’s I = 0.382) in southern Mexico. By 2024, the desert–adequate mortality gap had widened by approximately five fold (from ∼12 to 69 per 100,000 population). Conclusions: Healthcare deserts are independently associated with substantially higher avoidable mortality in Mexico. The COVID-19 pandemic durably amplified pre-existing disparities associated with healthcare infrastructure deficits. Targeted hospital expansion in underserved municipalities is urgently needed, alongside investment in social determinants of health.