State same-sex marriage policies and pre-exposure prophylaxis implementation among men who have sex with men in the United States.

Abstract

More than 70% of new HIV diagnoses in the United States were among men who have sex with men (MSM) in 2019. Pre-exposure prophylaxis (PrEP) is a transformative innovation for reducing human immunodeficiency virus (HIV) infections. Structural stigma against sexual minorities, including in the form of state-level policies, may affect PrEP implementation. We evaluated whether lower structural stigma reflected by earlier year of state same-sex marriage legalization was associated with increased male PrEP prescriptions and male PrEP-to-need ratio (PnR), a ratio of PrEP prescriptions to new HIV diagnoses. We used 2012-2019 AIDSVu data on male PrEP prescriptions and male PnR in each US state and year. We used generalized estimating equations to evaluate the relationship between the timing of implementing state same-sex marriage policies and the outcomes of male PrEP prescriptions per 100,000 people and the male PnR. We adjusted for calendar year, Medicaid expansion and the political party of the governor in each state. State implementation of same-sex marriage policies in earlier, relative to later, periods was associated with increases in the rate of male PrEP prescriptions and in the male PnR. Specifically, implementing state same-sex marriage policies between 2004 and 2011 and between 2012 and 2013 were each associated with greater rates of male PrEP prescriptions relative to implementing same-sex marriage policies between 2014 and 2015. Implementing state same-sex marriage policies between 2004 and 2011 as well as between 2012 and 2013 were both significantly associated with a greater male PnR relative to implementing same-sex marriage policies between 2014 and 2015. By 2019, the difference in male PrEP prescriptions was 137.9 (97.3-175.5) per 100,000 in states that implemented same-sex marriage in 2004-2011 and 27.2 (23.3-30.5) per 100,000 in states that implemented same-sex marriage from 2012 to 2013, relative to states that implemented same-sex marriage in 2014-2015. Earlier implementation of state same-sex marriage policies was associated with greater rates of male PrEP prescriptions. Reducing state-level structural stigma may improve HIV prevention among MSM in the United States.