Abstract
AIMS: To determine the areas of Spain with the most increased mortality risk. METHODS: Age adjusted relative risk of death by gender was estimated in each of 2218 small areas of the country using a non-parametric empirical Bayes method. To determine areas with "significantly increased risk" a Poisson based score test was used. RESULTS: Mapping of the highest risk areas showed a striking geographical clustering in the southwestern region of the country. This region, comprising 8% of the Spanish population, accounts for about one third (2884 deaths) of the total excess mortality.