ICD-Based Cause of Death Statistics Fail to Provide Reliable Data for Medical Aid in Dying.

To evaluate the most recent developments of medical aid in dying (MAID) in Switzerland and to test the reliability of reporting this phenomenon in cause of death statistics. By reviewing the MAID cases between 2018 and 2020, we compared the diseases and conditions underlying MAID reported by the ICD-based statistics provided by the Swiss Federal Statistical Office (FSO, = 3,623) and those provided by the largest right-to-die organization EXIT ( = 2,680). EXIT reported the motivations underlying the desire for death in a mixture of disease-specific and symptom-oriented categories; the latter including, for example, multimorbidity (26% of cases), and chronic pain (8%). Symptom-oriented categories were not included in the ICD-based FSO statistics. This led to the fact that the distribution of the diseases/conditions underlying MAID differed in 30%-40% of cases between both statistics. In order to reliably follow developments and trends in MAID, the diseases/conditions underlying the wish to die must be accurately recorded. Current methods of data collection using the ICD classification do not capture this information thoroughly ("MAID gap"). Newly created ICD codes for MAID must include both disease-specific and symptom-oriented categories.