Spatial Analysis of Cerebrovascular Hospitalization Risk and Particulate Matter Effects: Evidence from Northern Spain

Cerebrovascular diseases are among the leading causes of mortality and disability worldwide. This study aimed to identify geographic patterns and sex differences in unplanned hospital admissions for cerebrovascular diseases, and to assess their association with ambient air pollution within small areas of Asturias, a northern region of Spain that exhibits elevated rates of mortality and morbidity from these pathologies. The study included 20,305 unplanned hospital admissions recorded between 2016 and 2023. Standardized admission ratios, smoothed relative risks, and posterior risk probabilities were estimated using reparameterized Besag–York–Mollié models at the census tract level. Global and Local Moran’s I statistics were computed to evaluate the spatial correlation of admissions. Subsequently, estimates of PM10 and PM2.5 concentrations were incorporated into the models, adjusting for average net income per person, to assess their association with admission risk and their contribution to the geographical patterns observed. Spatial analysis revealed marked inequalities in cerebrovascular admissions both between sexes and across small areas. High-risk clusters were consistently identified in the north-central coastal area for both sexes. For men, higher PM10 and PM2.5 levels were statistically significantly associated with hospitalizations (PM10: RR = 1.08, 95% CI: 1.02–1.14; PM2.5: RR = 1.22, 95% CI: 1.07–1.40, per 5 µg/m3 increase) and explained part of the spatial variability observed. For women, neither pollutant showed statistically significant associations nor appeared to be associated with the geographic patterns. Integrating both geographic and sex-related factors is essential for identifying high-risk areas and potential risk factors in the burden of cerebrovascular disease. In men, exposure to PM10 and PM2.5 was associated with cerebrovascular hospitalizations and explained part of the spatial variability observed, while no such association was found in women.