Thiago S. Torres, Brenda Hoagland, Carolina Coutinho, Mayara Secco Torres Silva, Ronaldo I. Moreira, Iuri Costa Leite, Marcelo Cunha, Emilia M. Jalil, Sandra Wagner Cardoso, Roberta Trefiglio, Alessandro Farias, Maria Paula G. Mourão, José Valdez Madruga, Josué N. de Lima, Ronaldo Zonta, Gabrielle O’Malley, Júlio Moreira, Keila Simpson, Heather A. Pines, Alex R. Rinehart, Nanlesta Pilgrim, Paula M. Luz, Marcos Benedetti, Cristina Pimenta, Valdilea Gonçalves Veloso, Beatriz Grinsztejn
Background: Long-acting injectable cabotegravir (CAB-LA) offers a promising alternative to daily oral PrEP. However, studies evaluating PrEP choice and mHealth tools designed to support informed PrEP decision-making in real-world public health settings are scarce. We evaluated PrEP choice and the impact of an mHealth tool. Methods: ImPrEP CAB Brasil is a prospective, multicenter, quasi-experimental, implementation study conducted in six public health services in Brazil. Eligible participants were PrEP-naïve cisgender men, transgender and non-binary persons who have sex with men, aged 18-30 years, who tested negative for HIV. Participants were offered a person-centered model that provided a choice between same-day delivery of CAB-LA and oral PrEP. To support informed decision-making, participants were allocated (1:1) to standard-of-care counseling (SOC) or mHealth tool + SOC (first half enrolled in each site received SOC and the remaining received mHealth + SOC). Modified Poisson regression models estimated the effects of exposures of interest, study arm and Decisional Conflict Scale (DCS), on CAB-LA choice. Registered at ClinicalTrials.gov (NCT05515770). Findings: From October-2023 to October-2024, 1447 participants were enrolled: 738 (51.0%) to SOC arm and 709 (49.0%) to mHealth + SOC arm. Overall, 1201 (82.9%) participants chose CAB-LA. Participants allocated to mHealth + SOC arm were more likely to choose CAB-LA compared to SOC (PR: 1.15; 95% CI 1.10-1.21). Higher DCS scores were associated with a lower prevalence ratio of choosing CAB-LA (PR: 0.99; 95% CI 0.98-0.99). A total of 678 (95.7%) participants were satisfied with the mHealth tool and 659 (92.9%) found it supported PrEP decision. Interpretation: We found a strong preference for CAB-LA among young sexual and gender diverse populations. The mHealth intervention was highly acceptable and supported informed-decision, indicating its utility as a scalable strategy in real-world settings. These findings are crucial for guiding the equitable scale-up of CAB-LA and advancing HIV prevention in Latin America. Funding: Unitaid, WHO, Brazilian Ministry of Health.