Regional heterogeneity in the association between extreme temperatures and emergency hospitalizations in Germany

Abstract

The association between extreme temperature and emergency hospitalizations may differ by regional socioeconomic deprivation and its intersection with age and urbanization. This study investigates how regional characteristics modify the relationship between temperature and emergency hospitalizations in Germany. We analyzed the weekly emergency hospitalization rate by German districts (2005-2021) using the German Diagnosis-Related Groups Statistic, linked with high-resolution temperature data from the European gridded daily observational dataset (E-OBS). We fit a fixed effects model and interact regional socioeconomic deprivation with the weekly number of days falling into one of eleven temperature bins, adjusting for seasonality. Analysis was stratified by urbanization and age group. We observe 112,909,391 emergency hospitalizations over the study period. Among rural districts, an additional heat day is associated with 17.6 (95% CI: 12.3–23.1) additional emergency cases per 10,000 in the least-deprived districts, with no change in the most-deprived districts. Among ages 65+, an additional heat day is associated with the largest increase in emergency hospitalizations in medium-deprived compared to least-deprived districts. Our study finds that the temperature-emergency hospitalization relationship varies across German regions, with differences only becoming visible if regions are profiled by several characteristics. This highlights the need for an intersectoral approach to adequately address the differential impact of climate stressors on inpatient care uptake.