Cluster analysis of sub-national differences in life expectancy at birth in the European Union

BACKGROUND: Life Expectancy (LE) at birth, the average number of years a person is expected to live from birth, supposing constant age-specific mortality, is an essential indicator of a country or region's well-being, reflecting policy options at the regional level and highlighting progress and gaps in societal health, including at the sub-national level. In this study, our goal was to explore patterns on groups of European Union (EU) member states according to sub-national gaps in LE at birth, between 2000 and 2020. METHODS: A longitudinal retrospective analysis on differences in LE at birth among NUTS2 regions in 20 EU countries (due to data availability issues) was performed, taking the largest absolute difference between NUTS2 regions, in 2000-2020, as the country value. A hierarchical agglomerative cluster analysis was then performed. All data was retrieved from Eurostat and analysis performed in R version 4.0.0. RESULTS: 3 clusters were identified: (1) Belgium, France, Czechia, Hungary, Portugal and Spain (cluster mean: 3.78); (2) Austria, Slovenia, Croatia, Romania, Bulgaria, Poland, Finland, Germany, Italy and Greece (cluster mean: 2.44); (3) Denmark, Netherlands, Sweden and Lithuania (cluster mean: 1.17). CONCLUSIONS: 3 clusters of EU member states based on sub-national gaps in LE at birth were identified. Further studies are necessary to assess possible associated factors, such as health expenditure and health system efficiency, in order to better inform public policy and close the gap on existing inequalities. KEY MESSAGES: • Important sub-national differences in LE at birth exist in the EU, with considerable variability across groups of countries. • These results may have an important impact on policy-making and inequalities.