Variable definitions.

Standard surveillance definitions are used to code data in the HIV registry, are used in the NYC Annual HIV Surveillance Reports ^[3], and were retained for this analysis. Demographic variable and transmission risk definitions followed CDC conventions for surveillance reporting. Birth sex was classified as male or female. Transmission risk was classified hierarchically based on a documented history of IDU, a history of male-to-male sex contact (MSM), a history of sexual contact with a person of the opposite sex and no history of IDU or MSM, birth to a mother diagnosed with HIV, other (e.g., occupational or iatrogenic transmission), or unknown transmission risk. PWID who reported male-male sexual contact were classified as MSM/PWID.