Evolution and trends in referrals to a specialist gender identity unit in Spain over 10 years (2012-2021)

International studies have reported an increase in referrals to gender identity units, a shift in the assigned sex ratio of adolescents, a decrease in the age at first visit, and a growing presence of individuals with nonbinary gender identities.

To investigate whether these trends are present in a Spanish sample of individuals referred to a gender identity unit over the last 10 years.

We conducted a retrospective chart review of 913 consecutive referrals to a gender identity unit between 2012 and 2021 and retrieved information regarding sex assigned at birth, age at first visit, and expressed gender identity. We stratified the patients into 5 age categories: children (<12 years), adolescents (12-17 years), young adults (18-25 years), adults (26-45 years), and older adults (>45 years). The data were analyzed via descriptive and regression analyses.

Outcomes included the number of annual referrals, age at first visit, assigned sex ratio, and individuals with nonbinary gender identities.

The number of referrals increased 10-fold, from 18 in 2012 to 189 in 2021. The rates of increase over time were significantly more pronounced for adolescents and young adults and significantly greater for those assigned female at birth (AFAB). The age of referrals at first visit decreased, and AFAB individuals were, on average, younger than individuals assigned male at birth. The assigned sex ratio favored AFAB patients among adolescents (2.4:1) and young adults (1.75:1). Logistic regression showed that the odds of a new referral being AFAB increased by 9% per calendar year and that adolescent and young adult new referrals were significantly more likely to be AFAB. There were 21 referrals of nonbinary individuals starting in 2017, making up 6.4% of applications in 2021 and 2.9% during the last 5 years.

The evolution and trends observed in this study highlight the need for expanded resources, competent care, and careful reflection about implications for best practice.

This investigation involves a large sample of patients and is the first in our country to include people of all ages. However, the findings might not be generalizable to other gender identity units or the broader population of gender-diverse individuals.

Overall, our findings were consistent with previous international reports. We observed a marked increase in referrals, particularly among AFAB adolescents and young adults, a decreased age at first visit, and a growing presence of nonbinary individuals.