The most promising approach to slowing the spread of HIV may be a pill that uninfected people can take to protect themselves. But that strategy only works if people at risk for contracting HIV become and remain fully engaged in preventive care and actually take the pills. In the real world of clinical practice, that has often proved tricky.
In a new study, published in the journal AIDS, researchers propose a new system for understanding and evaluating how clinicians implement the pill, pre-exposure prophylaxis (PrEP). By viewing the process as a continuum with nine specific steps, they write, healthcare providers can properly assess where patients might fall out of preventive care that can help them remain HIV-negative.
“It’s helpful to visualize PrEP care as a continuum, because patients can drop out at any point on this long continuum,” says Philip Chan, assistant professor of medicine at Brown University’s Warren Alpert Medical School. “We are providing a framework for how we can identify and assist people who are at high risk for acquiring HIV to stay uninfected.”
In these early days of PrEP programs, physicians nationwide say it’s sometimes difficult to retain patients in care and ensure that they are keeping up with—or “adhering”—to their medicine, says lead author Amy Nunn, associate professor at the Brown University School of Public Health. In early academic trials of PrEP, adherence to the medication was promising, but outcomes in research studies are often different than in the grittier domain of real-world clinical settings.
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“Important research trials and CDC-funded demonstration projects have proven PrEP was overwhelmingly effective in reducing HIV acquisition,” Nunn says. “But it’s time to move beyond research trials to implement and study how to scale PrEP in safety net and primary care settings, where it’s needed most. We propose an approach based on our experiences providing PrEP to people in real-world clinical settings that helps us evaluate how to measure population progress.”
In a study last year analyzing the progress of clinical programs in cities in Rhode Island, Mississippi, and Missouri, researchers found that among patients who sign up to begin PrEP, only about 60 percent remained in care after six months.
The goal of the new study was to identify elements of the process where interventions could improve access to PrEP and the retention of patients in care.
Nine proposed steps
- Identify individuals at highest risk for contracting HIV
- Increase HIV risk awareness among them
- Enhance PrEP awareness
- Facilitate PrEP access
- Link to PrEP care
- Prescribe PrEP
- Initiate PrEP
- Adhere to PrEP
- Retain patients in PrEP care
Recently, researchers have looked at a looser progression of four steps (identifying those at risk, increasing PrEP knowledge, ensuring access to PrEP, ensuring medication adherence), but Chan and Nunn say that such a general process leaves too many gaps where problems can be missed.
“The process is more complicated and nuanced than many people think,” Chan says.
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For example, even when some patients have been identified as being at risk to contract HIV and have been well-informed about what PrEP is, they still might not appreciate their HIV risk enough to feel sufficiently motivated to take the medicine. PrEP does have side effects and can be expensive. That’s why the steps of identifying patients who are suitable candidates for PrEP and making sure they understand their degree of HIV-infection risk are critical.
The researchers also note that adherence is not always the most accurate measure of success for evaluating the public health impact of PrEP. Retention in care may be more important. On one hand, adherence to PrEP isn’t the only measure that high-risk patients should take to protect themselves from HIV transmission—routine testing for HIV and other sexually transmitted diseases, counseling about reducing sexual partners, using condoms, and understanding community-level HIV risks can also be important.
On the other hand, some patients may no longer require PrEP over time as they change their risk behaviors and sexual partnerships. A person who settles into a monogamous sexual relationship and practices safe sex might not need PrEP anymore, but that shouldn’t be perceived as a failure that requires intervention.
A future study will focus on when people cease to be retained in care and why. In some cases, patients are lost to follow up and don’t take their medications because they may lose their health insurance or not have sufficient support services to overcome other barriers to taking PrEP medications.
For that reason, Nunn advocates for funding PrEP navigators who can help high-risk patients overcome barriers, such as insufficient insurance, to stay engaged in preventive care.
The research was funded in part by the National Institutes of Health.
Source: Brown University
