the number of centenarians in Spain has continued to grow in the last few decades, reaching almost 6000 at present. The aim of this study was to analyze, from a geodemographic perspective, inter-provincial imbalances and the relative importance of the centenarian population in Spain.
data were gathered from the last Census of Population and Housing, updated with data from the Municipal Census of Inhabitants for 2006. The rates of centenarians per 100,000 inhabitants, location indices, and sex ratio were calculated.
in Spain the rate of centenarians showed a widely unbalanced territorial distribution: when the first five provinces were compared with the last five provinces, the ratio between the average rate of centenarians and the population aged 85 years and older was 3 to 1. This ratio increased to 4 to 1, when persons aged 65 years and older were considered.
the imbalances shown by the rates of centenarians in Spain can be explained by inter-provincial differences in social development, cultural context, environmental and territorial factors, together with the contribution of geographic factors, which are less well-known and analyzed than those termed "individual factors of longevity". Undoubtedly, these latter factors, which have a hereditary or genetic component, are involved. A satisfactory explanation would have to take into account the interplay between geographic and individual factors.