Dr. Patrick Sullivan, PhD, is a Professor of Epidemiology at Emory University’s Rollins School of Public Health and the Principal Scientist at AIDSVu.
Q: Newly released data from your paper, “Methods for county-level estimation of pre-exposure prophylaxis coverage and application to the US Ending the HIV Epidemic Jurisdictions,” published in Annals of Epidemiology showed that of the people in the EHE counties who used PrEP in 2018, 94% were men and 6% were women, which mirrors trends that we see at the national level. How can public health officials ensure that women who would benefit from PrEP are receiving it?
From a public health perspective, we would like to see the levels of PrEP use reflect the epidemic need by matching the distribution of those newly diagnosed with HIV. In the U.S., almost four out of five of those newly diagnosed with HIV are men and about one out of five are women. However, what we see in the PrEP use data is while women account for 20% of all new HIV diagnoses, they only account for 6% of PrEP prescriptions.
One of the challenges programmatically is the differences in modes of HIV transmission between men and women. Around 70% of new HIV diagnoses in men are attributed to male-male sex. Those men who have sex with men (MSM) are probably 3% or 4% of the total male population, which shows how HIV has a disparate impact on MSM. By contrast, 85% of new diagnoses in women are attributed to heterosexual contact and women having sex with men is a highly prevalent behavior. The question is: How do we reach those women who are most likely to be at risk?
There are a few ways of doing this, one of which is training healthcare providers, especially primary care providers and obstetricians and gynecologists, on how to discuss HIV risk and PrEP with their patients in a respectful and culturally sensitive way and how to offer PrEP to eligible patients who are interested. Sexually transmitted infections (STIs) are an important indicator because they’re a marker for women who have had sex that is not protected by condoms, and STIs increase the risk of acquiring HIV biologically. Additionally, we need to make women more aware of PrEP and normalize its use among women so that if women might benefit from PrEP, it’s not seen as a prevention tool that is mostly directed toward Gay and Bisexual Men.
Q: The federal Ending the HIV Epidemic: A Plan for America (EHE) initiative focuses on 48 counties, plus San Juan, PR, and Washington, DC, where more than half of all new HIV diagnoses occurred in 2016 and 2017, as well as seven states with a substantial rural HIV burden. Your research found that rates of PrEP use – an important HIV prevention tool and a core pillar of the EHE strategy – varies greatly among these 57 EHE jurisdictions. Why do you think these disparities exist?
It’s important to understand the challenges preventing people who might benefit from PrEP from accessing it and what’s been done to overcome those barriers. Some of the factors that contribute to this are the individual-level barriers that may prevent people from understanding that they may benefit from PrEP and then knowing where to find a provider. On AIDSVu, we also have a PrEP locator, where people can be directed to the PrEP prescribers that are closest to them, to help overcome this barrier.
Similarly, there’s the question of access. Part of the reason for the disparity in the uptake, which is also highlighted in our paper, are the big differences in the concentration of PrEP providers in different cities and coverage of PrEP. When looking into this we have to ask certain questions. For example, if I decide that I want to start PrEP, how close is the closest PrEP clinic to me? How easy is it going to be for me to get in and meet with a provider if I decide that I do want to get PrEP? Will I be treated in a respectful, non-stigmatizing way? Then, once I get in to see a PrEP provider, how do I pay for PrEP services? Those are really important questions to ask when researching the role public programs play in increasing awareness and uptake of PrEP.
In the jurisdiction paper, we talk about how common it is for the PrEP providers to accept Medicaid as a source of payment. Generally, we would think that in areas that have a higher proportion of providers who are accepting Medicaid as a source of payment there would be lower barriers to able to pay for PrEP. However, in many areas, less than half of providers accept Medicaid.
Currently, there is broad variation in the extent to which health departments engage in PrEP education. There are great examples of local campaigns to increase awareness of PrEP and increase PrEP use by state or local health departments. Looking at the state-level programs, we found the states that started early with programs to provide PrEP-related outreach and navigation and to directly offset the costs associated with taking PrEP, like New York and Washington State, have had a real leg up in increasing the number of people who are using PrEP. There’s a lot of variability in how quickly health departments took on the mission of PrEP education and how much has been invested locally.
I am hopeful there will be more national attention and investment in PrEP with the implementation of Ending the HIV Epidemic: A Plan for America.
Q: Your analysis identified significant disparities in PrEP use existing across the 48 counties. For example, in San Bernardino County, California, the rate of PrEP use was 19 users per 100,000 population in 2018 compared to 492 PrEP users per 100,000 population in New York County, New York. How does gathering data on current PrEP usage in these designated EHE jurisdictions inform local strategies to increase PrEP use and end the HIV epidemic?
When researching, we try to estimate how many people we think are in need of PrEP in a particular jurisdiction; CDC has done great work in developing these estimates. The question is ultimately how many people are eligible for PrEP and how many of those do we need to reach with PrEP in order to drive down new infections.
For example, among Gay and Bisexual Men and other MSM, we estimate that 30% to 50% of PrEP-eligible men would need to use PrEP to have a substantial impact on driving down new diagnoses. You can make an estimate for your own jurisdiction by using public tools like the PrEP impact estimator that Emory University and CDC jointly prepared. A jurisdiction can say, “How much PrEP do I need among MSM if I want to see a 30% reduction in diagnoses?” Then, using this tool, public health community members can establish a target number of PrEP-eligible men to aim for programmatically.
The last piece is, “How do I measure progress for my program against my objective?” If we need to get 50,000 men on PrEP in my jurisdiction and I only have 1,000 men on PrEP, that tells me something about how many resources I need to invest in order to reach the goal. Next year, if I come back and I have 10,000 more men on PrEP, I can also make some assessment of how much progress I’ve made.
Cities and jurisdictions often have very different levels of monitoring for PrEP need and use. Our research lets us make systematic comparisons between two locations – allowing us to give these jurisdictions a number that’s derived using consistent methods. Some jurisdicctions have local systems to estimate their levels of PrEP use; for those jurisdictions, our estimates provide a point of reference for their estimates. For some of these jurisdictions, it may be the first systematically derived measure of PrEP use that they have.
Q: Additionally, your research found that the PrEP-to-Need Ratio (PnR), or the ratio of the number of PrEP users to the number of people newly diagnosed with HIV, across the EHE counties varied significantly, from 1.0 in Duval County, Florida to 18.4 in New York County, New York. Can you explain some of the factors contributing to this geographic disparity?
The PrEP-to-Need Ratio (PnR) asks, “How many people in a jurisdiction are using PrEP relative to the number of people who are being diagnosed with HIV?” We’d like to see that the number of people using PrEP is in proportion to the required need. Putting a thousand people on PrEP in a county with a relatively low number of new diagnoses may be a sufficient response. Putting a thousand people on PrEP in a county with a large number of new diagnoses may be less impactful from a public health perspective.
When we see these variations in PnR, it’s just another way for us to be able to compare the responses in different kinds of jurisdictions. Using New York as an example, this is a city that started very early with a local health department response and with state-level investment to address barriers preventing people who need PrEP to get on PrEP. Because of this, we see New York has a large number of PrEP users, and a a very high PnR. For every new HIV diagnosis in New York, we see 18.4 people on PrEP. This is high when compared to Duval County, FL, for example, where there is one person on PrEP for every new diagnosis.
