Black women report higher levels of medical mistrust — hindering their access to an important HIV prevention medication — according to a new study published by researchers at the Yale School of Public Health and George Washington University.

The study documents that in 2016, black women, who make up 13 percent of women in the U.S., accounted for 61 percent of new women diagnosed with HIV. Uptake of an HIV prevention medication called pre-exposure prophylaxis, or PrEP for short, however, is significantly lower for black women than for white women. The study, which was published in the journal AIDS and Behavior on Sept. 27, aimed to determine the driving forces behind this disparity.

“Black women are 20 times more likely than white women to be infected with HIV,” said Mimi Tekeste, the lead author of the study and a Ph.D. candidate at George Washington University. “Racial minorities and women are much less likely to receive a PrEP prescription, and there was an early indication that medical mistrust is a barrier to PrEP access.”

According to the Centers for Disease Control and Prevention, PrEP is a preventative daily pill that individuals can take to prevent HIV from establishing a “permanent infection” if they are exposed to the virus. The CDC reports that taking the pill can reduce the risk of infection by up to 92 percent, making the medication particularly useful for high-risk populations.

Investigating the lower levels of PrEP use in black women compared to white women despite a higher relative rate of HIV infection, the team ultimately found that medical mistrust plays a significant role in access to the treatment for black women, as PrEP must be prescribed by a healthcare provider.

“The primary finding was that black women reported higher medical mistrust than white women, and this in turn was associated with lower comfort discussing PrEP with a healthcare provider,” said Sarah Calabrese, the senior author of the study and a professor of psychology at George Washington University.

The researchers used an indirect path to elucidate the role of medical mistrust in the differential uptake of PrEP among the two populations, Tekeste explained.

The researchers showed that the stigma of HIV indirectly affects PrEP access and leads to an intensification of previously existing racial disparities, according to Calabrese.

“Black women were more likely to have medical mistrust, and medical mistrust was associated with less comfort discussing PrEP with a health care provider,” Tekeste said. “An important finding is the need to increase efforts to build trust in the healthcare system among high-risk populations, racial minorities and traditionally marginalized populations.”

The research was part of a larger collaboration with Planned Parenthood of Southern New England focused on PrEP, according to Calabrese. The results from the study, which was supported in part by the Yale Center for Interdisciplinary Research on AIDS, will be used for a NIH grant application to study barriers to PrEP uptake among black and Latina women, she added.

And Tekeste “is currently brainstorming dissertation ideas focusing on understanding and addressing medical mistrust in particular,” Calabrese said.

In 2016, 39,782 individuals were diagnosed with HIV in the U.S., according to the CDC.

Vikram Shaw | vikram.shaw@yale.edu