Analysis Predicts Continued Disparities in PrEP Uptake

Large disparities in HIV pre-exposure prophylaxis (PrEP) use exist across different groups based on age, sex, and race and ethnicity. An analysis published in Health Affairs evaluated these disparities, finding major differences in PrEP uptake between different racial groups, and some of the greatest disparities among Black people.

The AIDSVu collaborative estimated the number of PrEP users increased 55% annually between 2012 and 2019, the authors explained. However, in 2020, less than a quarter of the amount of people predicted to have indications for PrEP were actually prescribed the HIV preventative. Other studies have partially credited the COVID-19 pandemic for the overall drop in PrEP prescriptions and new users in 2020, with stay-at-home orders, fear of exposure, and other restrictions likely impacting health care access for people at risk of acquiring HIV.

Disparities in uptake between groups, though, have existed long before the pandemic, including disparities between states. While California has the largest number of PrEP users by state, it was tenth in terms of PrEP uptake per capita in 2019.

In the same year, nearly three-fourths of new HIV diagnoses in the United States were among racial and ethnic minority groups, although a higher percentage of non-Hispanic White people were using PrEP between 2014 and 2017.

Additionally, in 2019, females made up 19% of new HIV diagnoses but only 7.4% of PrEP users, and Black females made up 55% of all female HIV diagnoses that year.

Using 2019 claims data for California Medicaid (Medi-Cal) enrollees aged between 16 and 69, the study authors predicted age-adjusted PrEP uptake rates. Uptake was measured as the proportion of eligible patients with Medi-Cal who filled at least one prescription for PrEP in 2019, based on racial and ethnic, sex, and age group.

Based on race and sex, predicted uptake was highest for White (0.29%) and Black (0.23%) males, and lowest for Asian (0.18%) and Hispanic (0.16%) males.

These predictions are not far off from the actual PrEP uptake rates in 2019. Percentages for Asian and Hispanic men were nearly identical to their predicted rates, with White (0.31%) and Black (0.25%) males having slightly higher actual uptake rates in 2019.

Uptake among females was lower across the board, with Black (0.06%) females having twice the PrEP uptake rate of White females (0.03%), and even higher rates than Asian (0.02%) and Hispanic (0.016%) females. These percentages are, again, nearly identical to predicted PrEP uptake rates.

Generally, the youngest (aged 16 to 24) and the oldest (aged 55 to 69) age groups had the lowest PrEP uptake rates in each racial group among both males and females. Males aged between 25 and 34 generally had the highest uptake rate based on age. Females aged between 35 and 44 mostly had the highest rate, with the exception of Hispanic females aged between 25 and 34 having a slightly higher rate.

The researchers also examined PrEP-to-need ratios—the number of PrEP users divided by the number of new HIV diagnoses—to understand uptake relative to HIV incidence. Black males and females as well as Hispanic males had PrEP-to-need ratios that were less than a third (4.0-6.3) of those of Asian and White males and females (14.4-19.9).

To account for different levels of behavioral risk between groups, the authors also accounted for a specific, largely behavioral indicator of HIV risk derived from the Behavioral Risk Factor Surveillance System (BRFSS). They found that males overall had higher BRFSS HIV risk than females, with the most high-risk group being Black males.

The authors originally suggested differing age distributions between populations, barriers in cost and health insurance coverage, and social factors attributing to access as factors in these disparities. After their analysis, they found only the social factors remained a potential influence in disparities.

“Although lack of health insurance is no doubt a factor contributing to disparities in health outcomes and utilization, the continued presence of disparities in this sample of Medi-Cal enrollees who all had access to PrEP at no cost points to the need to look beyond insurance to other factors that limit uptake of PrEP across demographic groups,” they wrote. “We can also reject the hypothesis that the differences in uptake arise from differences in age distribution across racial/ethnic groups because our age-adjusted estimates continue to show disparities between White men and men of other races/ethnicities.”

According to the authors, the type of Medi-Cal data used in this analysis could prove useful to track HIV prevention implementation as well as future HIV PrEP uptake disparities.

“Low PrEP use rates and disparities in uptake threaten efforts to end the HIV epidemic,” the authors concluded. “Policy makers must craft the rollout of innovations such as PrEP in a manner that narrows HIV disparities instead of widening them.”

Reference

Harawa NT, Tan D, Leibowitz AA. Disparities in uptake of HIV pre-exposure prophylaxis among California Medicaid enrollees. Health Affairs. 2022;41(3):360-367. doi:10.1377/hlthaff.2021.01119