New evidence of stagnation in mortality among young adults in Switzerland: a population-based study

To examine all-cause and cause-specific mortality by age group in Switzerland during and after the COVID-19 pandemic, in order to determine whether pre-pandemic trends recovered in 2023-24.

Standardised mortality rates since COVID-19 were compared with those expected by continuing trends estimated over the pre-pandemic years 2000-19 by log-linear Poisson models, resulting in estimates of all-age and age-specific excess death and mortality for 2020-24. Mortality trends for the leading causes of death were analysed by age group using Joinpoint regression models.

In 2024, all-cause mortality in Switzerland showed a complete return to pre-pandemic trends. However, marked differences between age groups were observed. While mortality among people aged 85 and over was significantly lower than trend in 2024 (-5.4% for men and -3.5% for women), people aged 65 to 84 were still struggling to recover the pre-pandemic trend this year (+4.2% for men and +3.5% for women). Mortality in the 15-44 age group began to stagnate a few years before the pandemic and remained significantly above trend in recent years, with excess mortality being systematically outside the 95% prediction intervals, reaching +33.6% for men and +20.4% for women in 2024. At the same time, accidents and suicides, among the leading causes of death in this age group, appear to have stopped declining, with a stabilisation in the suicide trend since 2014 among men (p = 0.005) and 2013 among women (p = 0.001), and in the accident trend since 2019 among men (p = 0.031). A slowdown in the decline of cardiovascular and respiratory mortality has been observed in the 65-84 age group.

The long-standing decline in mortality has stalled in recent years in Switzerland among young adults and, to a lesser extent, among young retirees, due to stagnation or slowdown of several major causes of death in these age groups. These phenomena, in addition to their importance for considering appropriate preventive interventions, also raise questions about the future of mortality and longevity in Switzerland and, more generally, in Western societies, and must be taken into account when developing realistic life expectancy and demographic scenarios. These are essential for decision-making in the areas of insurance, retirement planning and healthcare cost management.