Association between catastrophic health expenditure and mortality in older people in 11 European health systems: a longitudinal analysis between 2006 and 2020.

Introduction: Out-of-pocket expenditure (OOPE) and catastrophic health expenditure (CHE) challenge the financial protection provided by European health systems. Despite rising OOPE and CHE in Europe, evidence on health impact remains limited. This study examines the association between OOPE, CHE and all-cause mortality in older adults across 11 European countries from 2006 to 2020. Methods: We analysed longitudinal data from the Survey of Health, Ageing and Retirement in Europe, including 70 367 individuals aged ≥50 years across five waves (wave 2 (2006/2007), 5 (2013), 6 (2015), 7 (2017) and 8 (2019/2020)). CHE was defined as annual OOPE exceeding 25% of household income. Parametric survival models with Gompertz distribution estimated the association between CHE, OOPE and mortality, adjusting for socioeconomic and clinical covariates. Sensitivity analyses employed inverse probability weighting with regression adjustment. Results: Participants had a mean age of 65 years, 54% were women and 46% were retired. CHE was incurred by 1.6% of participants (range: 0.9%-2.2% by country). Over a mean follow-up of 3.8 years, 10.2% (7193) died. CHE was associated with an 84% increased mortality risk (95% CI 1.66 to 2.04), with the strongest effect in Switzerland (HR 4.22, 95% CI 2.54 to 7.00). Each €100 increase in total OOPE was associated with a 0.4% higher mortality risk (95% CI 1.002 to 1.006), especially in higher-income groups. OOPE on medicines showed heterogeneous effects: in the lowest income quintile, higher spending was associated with reduced mortality (HR 0.955, 95% CI 0.927 to 0.982), while in the third quintile (HR 1.044, 95% CI 1.017 to 1.071) and in countries like Czechia (HR 1.086, 95% CI 1.017 to 1.159) and Germany (HR 1.015, 95% CI 1.003 to 1.028), it was associated with increased mortality. Sensitivity analyses confirmed the main results. Conclusions: CHE and elevated OOPE are independently associated with increased mortality in older Europeans, suggesting negative long-term impacts on health. These findings underscore the need for cost-sharing reforms to preserve equity and protect vulnerable populations.