Pre-exposure prophylaxis (PrEP) has the potential to significantly reduce HIV incidence among men who have sex with men (MSM) in the United States. However, the extent to which suboptimal PrEP adherence and retention in care may limit successful implementation is unknown. An agent-based model was used to represent the entire population of MSM in Rhode Island from 2013 to 2017. The impact of potential interventions to improve PrEP adherence and retention in care on HIV transmission was evaluated. Demographics, behaviors, and PrEP adherence and retention in care rates were based on local clinical data. We assumed that 20% of HIV-negative MSM had ever taken PrEP. The primary outcome was HIV incidence over the 5-year period. The model included 23,815 MSM with an estimated 4.1% HIV prevalence based on local surveillance data. An estimated 173.1 new infections occurred over 5 years [95% simulation interval (SI): 171.5-174.7], including 29.1 new infections among individuals who had ever initiated PrEP (95% SI: 28.6-29.7). Interventions that improved retention in PrEP care by an odds of 5.0 compared with the base case maximized reductions in HIV incidence among MSM who had ever initiated PrEP by 37.5%. Interventions focusing on improving PrEP adherence had little to no effect on HIV incidence, regardless of intervention efficacy. Retention in care is a critical component of the PrEP care continuum. Interventions that improve retention in PrEP care may lead to greater reductions in population-level HIV incidence compared with interventions focused exclusively on adherence.
Keywords: HIV; MSM; PrEP; agent-based modeling; prevention.
Conflict of interest statement
No competing financial interests exist.
Potential Effectiveness of Long-Acting Injectable Pre-Exposure Prophylaxis for HIV Prevention in Men Who Have Sex With Men: A Modelling StudyBDL Marshall et al. Lancet HIV 5 (9), e498-e505. PMID 29908917.National Institute on Drug Abuse and National Institute of Mental Health.
Retention in Care Outcomes for HIV Pre-Exposure Prophylaxis Implementation Programmes Among Men Who Have Sex With Men in Three US CitiesPA Chan et al. J Int AIDS Soc 19 (1), 20903. PMID 27302837.PrEP initiation and retention in care differed across these distinct settings. In contrast, retention in PrEP care was consistently suboptimal across sites. Further resea …
The Cost-Effectiveness of Preexposure Prophylaxis for HIV Prevention in the United States in Men Who Have Sex With MenJL Juusola et al. Ann Intern Med 156 (8), 541-50. PMID 22508731.PrEP in the general MSM population could prevent a substantial number of HIV infections, but it is expensive. Use in high-risk MSM compares favorably with other intervent …
Behavioral Interventions to Reduce Risk for Sexual Transmission of HIV Among Men Who Have Sex With MenWD Johnson et al. Cochrane Database Syst Rev (3), CD001230. PMID 18646068. - ReviewBehavioral interventions reduce self-reported unprotected anal sex among MSM. These results indicate that HIV prevention for this population can work and should be suppor …
Pre-Exposure Prophylaxis: A Narrative Review of Provider Behavior and Interventions to Increase PrEP Implementation in Primary CareA Silapaswan et al. J Gen Intern Med 32 (2), 192-198. PMID 27761767. - ReviewSince FDA approval of HIV pre-exposure prophylaxis (PrEP) for HIV prevention, attention has been focused on PrEP implementation. The CDC estimates that 1.2 million U.S. a …