Table 1.
HIV Incidence Rate, Percent of Infections Averted, and Number Needed to Treat by Risk Compensation Level, by PrEP Adherence Level and Partnership Types, among US MSM.
Fig 1.
The HIV incidence rate per 100 person-years at risk (Panel A) and percent of infections averted relative to a scenario in which no PrEP was used (Panel B), by the interaction of relative levels of condom-related risk compensation (RC) and PrEP adherence profile in which compensation occurred.
The red line depicts RC in all four PrEP medication adherence profiles (high, medium, low, and non-adherent), the blue in the top three (high, medium, low) green in the top two (high and medium) and purple in the high only. The horizontal dashed lines shows a comparison of the two outcomes (incidence and PIA) if RC were not to occur (0% RC). All points summarize the empirical distribution of 250 simulations of each scenario.
Table 2.
Individual-Level Risk and Time on PrEP by Risk Compensation Level, by PrEP Adherence Level and Partnership Types, among US MSM.
Fig 2.
The expected rate of HIV acquisition per 1000 discordant exposures for all MSM (Panel A), and for MSM who were currently using PrEP (Panel B) or not using PrEP at the time of exposure (Panel C), by the interaction of relative levels of condom-related risk compensation (RC) and PrEP medication adherence profile in which compensation occurred. Panel D shows the amount of person-time on PrEP per 100 possible person-weeks for susceptible MSM. The red line depicts RC in all four PrEP adherence profiles (high, medium, low, and non-adherent), the blue in the top three (high, medium, low) green in the top two (high and medium) and purple in the high only. The horizontal dashed lines shows a comparison of the two outcomes (incidence and PIA) if RC were not to occur (0% RC). All points summarize the empirical distribution of 250 simulations of each scenario.
Fig 3.
Schematic diagram showing the feedback loop between increased risk compensation, higher behavioral indications, and PrEP uptake among a four-person network over four time steps.
At t0, Node 1 (N1) engages in condom unprotected anal intercourse (UAI) outside of a monogamous partnership (with N2 and N3), which leads to his indications for and uptake of PrEP at t1. In the risk compensation (RC) scenario, PrEP is associated with an increase in UAI (with N2), a PrEP non-user, whereas in the counterfactual no RC scenario, behavior remains the same as protected anal intercourse (PAI). At t2, N2 has engaged in UAI with N1 in the RC scenario, becomes indicated for PrEP, and uses it before initiating UAI with N4, an HIV-infected (status unknown) partner. In the No RC scenario, the PrEP uptake is delayed until t3, but N2 has already become infected by N4.