This cross-sectional study used 2012 to 2019 Oregon Medicaid claims to estimate the prevalence of PrEP use and identify determinants of high adherence across transgender and cisgender men and women. Gender identity (cisgender woman/man; transgender, assigned female sex at birth [AFAB]; transgender, assigned male sex at birth [AMAB]) was based on medical history and enrollment records. Proportion of days covered ≥ 0.80 was considered high adherence to PrEP. The association between gender identity and PrEP uptake or high adherence was estimated using multivariable logistic regression. 1555 PrEP users, including 171 (11.0%) cis women, 1171 (75.3%) cis men, 67 (4.3%) AFAB, and 146 (9.4%) AMAB individuals, were included. The probability of PrEP use per 10,000 people was highest in transgender groups (AMAB 546.8, 95% CI 462.4-631.3; AFAB 226.5, 95% CI 173.4-279.6), followed by cisgender men (20.6, 95% CI 19.4, 21.8) and women (2.6, 95% CI 2.2, 3.0). High adherence was significantly lower in AMAB recipients (72.6%) than cisgender women (86.0%) and cisgender men (82.2%). Among the 279 PrEP users with female on their enrollment record, 76 (27.2%) were AMAB, while among the 1276 PrEP users with male on their enrollment record, 35 (2.7%) were AFAB. This demonstrates the importance of surveillance methods that take gender identity into account in addition to sex assigned at birth. There were significant differences in PrEP use and adherence by gender identity. PrEP surveillance, outreach, and prescribing practices must consider gender identity-unique risk factors.
Keywords: Adherence; Differential misclassification; Medicaid; Pre-exposure prophylaxis (PrEP); Transgender.
© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.