Gender-Affirmation Surgery in Denmark: A Nationwide Register-Based Cohort Study

Purpose: Gender affirmation surgery (GAS) refers to surgical procedures that align physical appearance with gender identity. Data are limited regarding GAS in national cohort studies and we aimed to assess GAS in Danish transgender persons.Methods: We conducted a national register-based cohort study in Danish transgender persons. Persons with International Classification of Diseases (ICD)-10 diagnosis code of "gender identity disorder" were included during 2000-2021 and surgical procedure codes were identified up to and including June 2022.Results: The cohort included 3812 transgender persons with median age (interquartile range) at study inclusion 19.0 (15.0; 24.0) years for persons assigned female sex at birth (AFAB, N=1993) and 23.0 (19.0; 33.0) years for persons assigned male sex at birth (AMAB, N=1819). The mean (standard deviation) follow-up duration was 4.5 (4.3) years. In persons AFAB, the 5-year cumulative incidence for GAS increased from 14.9 (7.0; 25.6) for persons diagnosed in 2000-2005 to 50.0 (45.9; 53.9) for persons diagnosed in 2014-2018. In persons AMAB, the 5-year cumulative incidence increased from 7.1 (3.5; 12.4) to 17.0 (13.8; 20.4). The mean waiting time from study inclusion to event of any GAS, top surgery or genital surgery, decreased throughout the study period in persons AFAB and persons AMAB. Genital constructive GAS was conducted in 1.4% transgender persons.Conclusions: The incidence of GAS increased and waiting time decreased for transgender persons diagnosed during 2000-2018. Genital constructive GAS was rarely performed in Danish transgender persons.