Trustworthiness criteria applied in this work.

Transgender women [TGW] in Colombia are disproportionately affected by HIV due to their low sociodemographic conditions, varied risk behaviours, difficulty accessing health services, and discrimination. Offering pre-exposure prophylaxis [PrEP] as part of a combination of prevention strategies is an appropriate option for this population to reduce their risk of HIV infection. However, little is known about how to implement a PrEP program for TGW in Colombia. Between June and October 2020, we conducted individual interviews with 16 TGW from four different cities in Colombia. The interviews assessed contextual influences, knowledge, skills, perceptions, and beliefs. We used qualitative thematic analysis to identify themes and the Capability, Opportunity, Motivation, and Behavior framework to further delineate barriers and possible interventions. After delineating the main themes across the three subdomains of the model, nine barriers were identified: one related to capability, knowledge, and perception of PrEP; six related to opportunity, which includes, family relations, sexual work environment, stable partner relations, interactions with healthcare workers, health service provision, and community interactions and opportunities; and two related to motivation, mental health, and concerns about medication side effects. Mapping barriers with interventions generated the following intervention functions: education, training, enablement, and environmental structure; and the following policy functions: communication/marketing, legislation, and changes in service provision. Examples of possible interventions are presented and discussed.