Winter life expectancy reduction in Europe

Background: Mortality is known to be higher in winter than in summer, with excess winter deaths ranging between 5% and 30% in Europe. A recent study conducted in the USA sought to quantify the excess winter mortality in terms of life expectancy reduction, by calculating the difference between summer and winter life expectancy. Objective: We aimed to calculate Winter Life Expectancy Reduction (WLER) in Europe, illustrate the extent to which this indicator depends on definitions of summer and winter, introduce a novel indicator of WLER based on a statistical model accounting for country-specific seasonal cycles, and compare men and women in terms of WLER. Methods: WLER indicators were calculated from weekly mortality data in 24 European countries over the period 2000–2019. Results: On average, WLER was a few months higher in Europe than in the USA, while depending heavily on country and sex, as well as the chosen indicator. Our model-based indicator measured the highest WLER values, ranging from 11 months (Finnish men) to 36 months (Portuguese women), with a European average of 18 months for men and 22 months for women. In most countries, WLER was higher for women than for men, regardless of the indicator used. Contribution: This is the first study to calculate WLER in Europe. It raises the intriguing scientific question of why women have a greater WLER than men. While life expectancy remains systematically higher in summer than in winter, our model also revealed a decline at the height of summer in Mediterranean countries.