Incidence and Prevalence of Reported Euthanasia Cases in Belgium, 2002 to 2023.

Importance: Reported cases of assisted dying have increased in countries with such legislation. In Belgium, where euthanasia was legalized in mid-2002, cases rose from 236 in 2003 to 3423 in 2023. Most previous studies have focused on occurrence rates. Objective: To examine the magnitude of the increase in euthanasia cases and its association with demographic changes observed during the study period. Design, Setting, and Participants: This cross-sectional study analyzed complete data from the Belgian Federal Commission for the Control and Evaluation of Euthanasia (FCCEE) from September 1, 2002, to December 31, 2023, and adjusted the model for demographic composition and change by gender, age group, and region using data from the Belgian Office for Statistics. All cases of euthanasia reported to the FCCEE during the selected period were included. Exposure: Euthanasia reported to the FCCEE. Main Outcome and Measures: Poisson regression with and without a demographic offset was used to provide the rate ratios (RRs) and the prevalence rates (PRs) for euthanasia. The RRs were calculated by age, gender, region, and euthanasia characteristics. Estimates used a model including demographic offsets to calculate PRs and explore interactions across subcategories. Results: During the selected period, 33 647 cases of euthanasia were reported (50.23% male; 84.74% 60 years or older); analyses focused on 33 580 valid cases. The yearly RR was 1.07 (95% CI, 1.07-1.07), while the yearly PR was 1.05 (95% CI, 1.05-1.06), indicating that demographic changes were associated with the observed increase. The PR for euthanasia among males relative to females was overall higher (PR, 1.36; 95% CI, 1.33-1.39) but has decreased slightly (PR, 0.99; 95% CI, 0.99-1.00). Cases citing multimorbidity increased relative to those citing tumors (PR, 1.03; 95% CI, 1.02-1.04), whereas cases related to psychiatric disorders and deaths in care homes did not show significant increases. Higher prevalence was observed in the Flemish region relative to Wallonia (PR, 1.51; 95% CI, 1.47-1.55), but the gap has narrowed over the years. Conclusions and Relevance: This study found that a substantial part of the increase in euthanasia cases was attributable to demographic changes. Early increases were mainly due to the regulatory onset, while recent trends reflect a growing influence of demographic factors and regional adjustments. These findings suggest that considering demographic shifts is essential, and long-term trends should be monitored.