Age distribution of all-cause mortality over time following flood disasters

Abstract Background Floods are the most common natural disasters in Europe. While it is well documented that short-term flood fatalities predominantly affect children and the elderly, research on the age distribution of long-term deaths in flood affected communities is scarce. A recent study on Storm Daniel, which caused severe floods in Greece in September 2023, found increased all-cause mortality for up to three months following the disaster. The current study investigates the age distribution of excess mortality over time following Storm Daniel, in order to identify the most vulnerable age groups and inform targeted public health interventions. Methods This is an ecological time-series study. Excess deaths by age group (0-9, 10-29, 30-49, 50-69, 70+) were calculated as the difference between the observed deaths post-floods and the expected deaths based on historical mortality data (2015-2019) using a quasi-Poisson generalized linear model. Mortality and population data were derived from Eurostat and the Hellenic Statistical Authority, respectively. Results No excess mortality was found in individuals younger than 45 years old. Over three months, excess deaths cumulated to 51 (95%CI: 26-77) for ages 45-64, and 220 (95%CI: 118-321) among individuals older than 65 years old. Conclusions Our findings indicate that long-term mortality following floods primarily affects the elderly (over 65 years old), with a notable impact also observed among middle-aged adults, particularly those aged 45-64 years old, potentially reflecting the higher flood-related risk of cardiovascular and respiratory diseases in these age groups. These results highlight the need for continuous health monitoring of flood-affected populations and age-targeted public health strategies to mitigate emerging health risks and prevent avoidable deaths. Key messages • Long-term mortality after floods affects not only the elderly, but also middle-aged adults. • Age-targeted public health interventions are crucial after floods to address delayed health impacts and prevent avoidable deaths.