Background:
Pre-exposure prophylaxis (PrEP) is highly effective to reduce risk of HIV infection; the population-level impact of PrEP is predicted to depend on PrEP coverage (e.g., PrEP prescriptions among those with indications), adherence to prescribed PrEP, the extent to which PrEP is used by those at greatest risk for HIV infection, and the extent of viral suppression among community risk contacts.
Methods:
We used publicly available data on PrEP prescriptions and calculated PrEP coverage per 100 persons with indications in each state during each year. We calculated quintiles of mean PrEP coverage (e.g., proportion of PrEP users among people with an indication for PrEP) during 2012-2021 for 50 US states and the District of Columbia. For each quintile, we calculated the estimated annual percent change (EAPC) in HIV diagnosis rates from 2012-2021 with 95% confidence intervals using temporal trends models and calculated a p value for trend across state-specific quintiles of coverage. Because higher PrEP coverage in a state might be confounded by higher levels of viral suppression, we adjusted EAPC estimates for prior year state-level viral suppression.
Results:
The estimated state-specific EAPC in HIV diagnosis rates between 2012-2021 ranged from -11.9% (95% CI: -13.0%, -10.8% in Washington, DC) to +10.5% (95% CI: +5.1%, +16.2% in West Virginia). Mean PrEP coverage among states and the District of Columbia between 2012-2021 ranged from 3.8% (West Virginia) to 22.2% (New York). From 2012-2021, the quintile-specific change in HIV diagnosis rates ranged from a 1.7% increase (95% CI: -0.7% to +4.1%) in the lowest quintile of PrEP coverage to an 8.0% decrease (95% CI: -9.3% to -6.8%) in the highest quintile of PrEP coverage, after controlling for yearly changes in viral suppression rates (Figure; p value for trend across quintiles: 0.0077).
Conclusions:
In an ecologic analysis, increasing PrEP coverage was associated with decreasing new HIV diagnoses from 2012-2021 among US states, even controlling for differences in state-viral suppression. Our data suggest that PrEP coverage is a meaningful measure to assess the progress of PrEP programs. However, our analysis also documented stark differences in the trajectories of PrEP program among US states: there was an 8-fold difference between the extent to which PrEP needs were met between the lowest and highest performing states. PrEP coverage data is useful to monitor progress in state PrEP programs.
