The PrEP Cascade, a flowchart showing the stepped nature of the motivational PrEP cascade (Courtesy of The Black AIDS Institute)
When it comes to achieving any objective, knowledge is power. In the efforts to get more African Americans aware of and using pre-exposure prophylaxis (PrEP), an evolving tracking system called the PrEP cascade is providing new insights as we work toward better results.
PrEP is critical to the fight to end the HIV/AIDS epidemic because, when taken consistently, the anti-HIV medication can lower one's risk of getting infected by more than 90 percent. While it is no doubt a game changer, large numbers of Black Americans have not been benefiting from taking PrEP. In 2015, Whites made up 74 percent of those who used PrEP, while African Americans made up only 10 percent, according to Gilead Sciences, maker of the PrEP medication Truvada.
In order for PrEP to be more widely used in Black communities, a number of things have to happen. More people who are at risk of acquiring HIV must become aware of PrEP; those same people must find a provider who will prescribe it; and they must take the actual steps of beginning and staying in treatment. The PrEP cascade tracks those steps and identifies gaps in the continuum of care that are keeping more people from using and benefiting from PrEP.
Understanding the Stages of the Continuum
There are five stages to the PrEP cascade, according to the National AIDS Treatment Advocacy Project, which developed its model based on results from One Thousand Strong, a three-year, nationally representative study of gay and bisexual men of all racial and ethnic backgrounds in the United States:
- Stage 1 is called objective identification, which refers to the identification of people who would be ideal candidates for PrEP.
- Stage 2 is PrEP contemplation, which refers to the number of people who have learned about PrEP and believe that they are good candidates for it. Those in this stage have shown a willingness to take PrEP but have no means or plans to do so.
- Stage 3 is the "PrEParation" stage. Someone at this stage has already found a provider that will administer PrEP, and they intend to start PrEP.
- Stage 4 is the PrEP action and initiation stage. At this stage, a person has actually met with a provider and has obtained his or her prescription.
- Stage 5 is PrEP maintenance and adherence. It's not enough to start taking PrEP. It's important that the person adhere to the regimen and continue to take it. Those who make it to stage 5 of the PrEP cascade have started treatment, are adherent to the PrEP regimen, and get regular testing for HIV and other sexually transmitted infections.
What researchers have discovered is that, similar to the HIV treatment cascade (also called the HIV care continuum), the numbers of people decline with each subsequent stage. The largest number of people are in stage 1, after which people drop out at each subsequent stage. By studying the percentages of people who drop out in each stage, advocates can determine what roadblocks are keeping people from taking PrEP and adhering to the regimen over time.
It is also important to note that there have been different variations of the PrEP cascade whose steps differ somewhat, though they all have the same ultimate goal. For example, researchers at the Center for HIV Educational Studies & Training in New York created a cascade in 2016 (pdf), based on data from the iPrEx study, conducted among high-risk gay and bisexual men in Ecuador, Peru, Brazil, South Africa, Thailand and the United States. That cascade labeled the first stage PrEP precontemplation, in which the men being studied were unwilling to take PrEP or ruled themselves out as good candidates.
Identifying What Is Working
The PrEP cascade is a great way to see what's working in Black communities and what is not, says Hyman Scott, M.D., an infectious disease specialist at Zuckerberg San Francisco General Hospital and Trauma Center. Scott works closely with the San Francisco Department of Health on its PrEP Supports campaign (pdf), announced in February 2018, which is focused on increasing the use of PrEP in the African American community.
Not only is the PrEP cascade a way to track progress, but "there might be places that are blind spots" to health-care providers, where people fall off the cascade and that we need to learn more about, Dr. Scott says. "It's not always just a personal decision. Often it's insurance losses or a job change, or somebody loses their job, and they might lose access to health care. Those are very disruptive things that can happen in somebody's life."
By tracking an individual after he or she is initially referred for PrEP, advocates can gather information that helps them reach more people. Once that information is known, advocates can figure out what safety nets need to be put in place to ensure that those who are vulnerable don't fall through the cracks of the system, Scott adds.
The PrEP cascade also gives organizations that are working to increase PrEP usage a place to target their efforts. "I think that there's a focus on ensuring that Black Americans are aware of PrEP, and now that there are efforts to ensure that campaigns are representative of the community, I think that is a huge first step," Dr. Scott says. "Using the cascade to monitor [those efforts] will be helpful."
Tamara E. Holmes is a Washington, D.C.-based journalist who writes about health, wealth and personal growth.
[Note from TheBody: This article was originally published by The Black AIDS Institute on March 15, 2018. We have cross-posted it with their permission.]