Exploring spatial patterns of sarcoidosis mortality in Spain between 2009 and 2023

To describe temporal trends and spatial distribution of sarcoidosis-related mortality in mainland Spain between 2009 and 2023, with a focus on sex-specific differences and high-risk clusters.

An ecological study was conducted using mortality data from the Spanish National Statistics Institute (INE) for deaths coded as ICD-10 D86. Age-adjusted mortality rates were calculated using direct standardization to the European Standard Population 2013. Temporal trends were assessed with joinpoint regression, and spatial patterns were analyzed at the provincial level using standardized mortality ratios (SMRs), Bayesian-smoothed relative risks (RRs), and posterior probabilities via the Besag-York-Mollié model. Global and local clustering was evaluated with spatial scan statistics, Moran's I, and Local Indicators of Spatial Association (LISA).

Between 2009 and 2023, 709 sarcoidosis-related deaths were recorded (417 women, 292 men). Mortality increased significantly in men (average annual percentage change (AAPC) 4.5%, 95% CI 1.6-7.4%) but not in women (AAPC 1.0%, 95% CI -1.3-3.5%). Geographic analysis revealed persistent high-risk clusters in northwestern provinces, particularly Galicia and Castilla y León, whereas central and Mediterranean provinces exhibited lower-than-expected mortality. Sex-specific clustering patterns were evident, with women showing more widespread high-risk regions. Bayesian-smoothed relative risks and posterior probabilities corroborated these findings, indicating true excess risk rather than random variation.

Sarcoidosis mortality in mainland Spain demonstrates marked geographic heterogeneity and sex-specific patterns, with persistent high-risk clusters in the northwest. These results are suggestive of the interplay of genetic, environmental, and healthcare-related factors, providing a foundation for targeted surveillance, preventive strategies, and resource allocation.