A study spanning from 2012 to 2016 found an association between state increases in pre-exposure prophylaxis (PrEP) coverage and decreases in estimated annual percentage change (EAPC) in viral suppression, indicating the need to bring PrEP use to scale in the United States in order to reduce HIV infection numbers more efficiently.
According to the study, the number of new HIV infections have been decreasing slowly between 2008 and 2013 and the annual new HIV infections have remained stable from 2013 to 2016. Researchers have been prioritizing several methods of reducing HIV incidence, including sustained antiretroviral therapy (ART) for those already diagnosed with HIV infection and daily oral antiretroviral PrEP with coformulated tenofovir disoproxil fumarate (TDF) and emtricitabine (FTC) for those without HIV, but who have a significantly higher risk for infection.
Since the FDA approved TDF/FTC for PrEP in 2012, the US prescription rates of PrEP have increased from 8768 in 2012 to 77,120 in 2016 and 100,282 in 2017.
The ecologic analysis used data of HIV infection cases diagnosed during 2012-2016 from the CDC from each state and the District of Columbia, referred to in the study as jurisdictions.
The state average HIV diagnosis rates decreased from 13.1/100,000 persons in 2012 to 11.8/100,000 in 2016. Furthermore, average PrEP coverage among those prescribed increased from 0.7 per 100 in 2012 to 5.8 per 100 in 2016.
However, EAPC HIV diagnosis rates during the study period were not uniformly decreasing in all 50 states. For example, the District of Columbia saw a 14.4% decrease, whereas Nevada experienced a 4.3% increase, according to the study. Rates of PrEP coverage also varied across states: an increase of 16.0 per 100 was identified in New York and an increase of 1.5 per 100 occurred in Wyoming.
States were grouped into quintiles based on their change in PrEP coverage during 2012-2016. The 10 states with the greatest change in PrEP coverage experienced average EAPC of HIV infection diagnoses at a 4.0% decrease.
The results of the study suggested strong associations between jurisdictional increases in PrEP coverage and decreases in EAPC of HIV diagnoses.
Limitations of the study may include the fact that an ecologic analysis was used; it may be subject to unmeasured bias, and therefore it cannot be proven that the use of PrEP spurred changes in HIV diagnosis rates for any given state. However, the study does align with the assertion of many clinical trials the biologic mechanism of PrEP’s efficacy for HIV prevention.
Smith DK, Sullivan PS, Cadwell B, et al. Evidence of an association of increases in pre-exposure prophylaxis coverage with decreases in human immunodeficiency virus diagnosis rates in the United States, 2012-2016. Clinical Infectious Diseases. 2020;ciz1229. doi: https://doi.org/10.1093/cid/ciz1229.