Geographic inequalities in suicide mortality in Italy: Insights from spatial epidemiology

Suicide mortality displays consistent geographic variation, shaped by environmental, social, and structural determinants. Italy's diverse landscape and regional disparities offer a unique opportunity to investigate the spatial distribution of suicide risk.

This study examines the geographic patterns of suicide across Italy's 110 provinces and evaluates how altitude and population density contribute to regional disparities in suicide mortality.

Using official mortality data from 2006 to 2010, we calculated mean annual suicide rates per 100,000 inhabitants. Spatial autocorrelation was assessed using Moran's I and Local Indicators of Spatial Association (LISA). Spatial regression models-including the Spatial Autoregressive Model with Spatially Correlated Errors (SAR-SEM)-were applied to account for spatial clustering and examine geospatial predictors. A sensitivity analysis included demographic composition (age and gender) at the provincial level.

The national average suicide rate was 5.82 per 100,000 inhabitants, with significant spatial clustering (Moran's I = 0.23, p < 0.0001). High-rate clusters were concentrated in Northern Italy and Sardinia, while low-rate clusters predominated in Southern regions. Altitude and population density were significant predictors, but spatial modeling-especially the SAR-SEM-also identified unmeasured regional factors contributing to suicide patterns. Demographic composition showed weaker and less consistent associations than geographic and spatial factors.

Geographic disparities in suicide rates in Italy are linked to altitude and population density, with additional spatially structured influences. Sensitivity analyses confirmed that demographic factors play a limited explanatory role. These findings underscore the value of spatial epidemiology in suicide research and support geographically targeted prevention strategies.