Improving Data on the HIV Epidemic in New York City by Identifying Transgender Persons in Medicaid in 2013-2017.

Purpose: Undercounting of transgender people with HIV (PWH) in New York City (NYC) remains prevalent. We sought to improve our ability to accurately enumerate transgender PWH and address their needs for gender-affirming health care. Methods: We enhance previous algorithms used to identify transgender beneficiaries, using diagnoses, prescriptions, and sex at birth from Medicaid claims in 2013-2017. We then matched beneficiaries to individuals diagnosed with HIV in the HIV surveillance registry to identify transgender PWH. Results: Our algorithm identified 6043 transgender persons who accessed Medicaid in 2013-2017, with 1472 (24%) reported to the HIV registry, 1168 (79%) of whom were accurately identified as transgender in the registry. We found 292 transgender persons in the registry that had accessed Medicaid but were not identified by our algorithm, for a total of 6335 transgender persons accessing Medicaid (0.1% of the NYC Medicaid population), including 1764 transgender PWH (28% of transgender persons accessing Medicaid). From 2013 to 2017, there was a 35% increase in transgender persons identified in Medicaid claims using our algorithm. Conclusion: We identified a large number of transgender persons in Medicaid, many of whom were PWH. We saw a sizeable increase over the 5-year period, likely due, in part, to expansion of Medicaid policy to cover gender-affirming health care. Given the high proportion of transgender PWH accessing Medicaid, Medicaid claims data are a valuable source of health information for the transgender population, a group that is often difficult to identify due to issues of underreporting, stigma, reduced access to appropriate care, and misgendering by health care personnel.