LAUSR

Cases of reported euthanasia or assisted dying have increased in all countries that provide such legislation. In Belgium, the number of annual reported cases rose from 1,928 in 2014 to 3,423 in 2023. However, no study has addressed how this change reflects demographic composition. Using Belgian administrative data, the study shows actual trends and how population composition explains variations across sub-groups including age, gender, region and reason for euthanasia. We use complete micro-data on all cases of euthanasia reported between 2014 and 2023 (N = 24,840) gathered by the Belgian Federal Commission for the Control and Evaluation of Euthanasia (FCCEE). We apply Poisson regression controlling for time and use interaction terms to address time change over subgroups and provide Incidence Rate Ratios (IRR). We compare net estimates with a modelling weighting for population demographics generated from the Belgian Office for Statistics data. Data show an IRR of euthanasia of 1.06 (95%CI = 1.056;1.066) – i.e., an increase of 6% per year. Weighted for population characteristics, the IRR is 1.04 (95%CI = 1.039;1.049). Demographic composition explains such a difference, not demographic change. Unweighted data show higher incidence amongst female [male = 0.934 (95%CI = 0.911;0.958)] but the trend is reversed when weighting for demographics [male = 1.076 (95%CI = 1.046;1.105)]. Gender differences in reasons for euthanasia exist with cancers and psychiatric disorders more often observed in male and female respectively. Euthanasia is more common in the Flanders [3.058 (95%CI = 2.949;3.171)] and the demographic adjustment does not fully reduce the regional divide. Analysis on euthanasia and assisted dying should consider population demographics when addressing incidence amongst populations to better capture age, regional and gender differences.