Online HIV Risk Calculator Can Help You Identify if You Should Take PrEP

With 1.2 million individuals living with HIV in the United States alone, and 36.7 million individuals living with it worldwide, a preventive medication that can be taken by those at increased risk is imperative. Once someone gets the virus, the individual has it for life, and without antiretroviral therapy (ART), their condition can become more severe, even deadly.

In order to cut down these numbers, preventive measures should be taken, especially by those who find themselves at increased risk of infection. One of the strongest preventive measures currently available is PrEP, or pre-exposure prophylaxis. In fact, according to the Centers for Disease Control and Prevention (CDC), when antiviral drugs, such as Truvada, are taken consistently and on a daily basis, they can reduce the risk of acquiring HIV by over 90%.

The CDC has provided the public with guidelines pertaining to PrEP as a means to prevent HIV within the United States. Though helpful, a new study conducted by researchers from the UCLA Fielding School of Public Health posit that the guidelines may not be specific enough to identify certain PrEP candidates.

Since 2012, the CDC has recommended that the following individuals should use PrEP: gay or bisexual men who engage in anal sex without condoms, those who within the past six months have been diagnosed with a sexually transmitted disease, and men who do not have the virus but have sexual relations or are in relationships with someone who is HIV-positive.

Although these recommendations are certainly helpful, the authors of the UCLA study, published in Sexually Transmitted Diseases, posit that the guidelines “do not go far enough” in that they do not include essential variables that could work to increase an individual’s risk of infection, according to a press release on the study.

Working in collaboration with the one of the biggest HIV testing providers in Los Angeles county—the Los Angeles LGBT Center—the UCLA researchers developed an online risk assessment calculator, a tool that allows individuals to check their “PrEP score” by answering a series of questions that address a number of different variables that might put them at increased risk of infection.

When speaking of the calculator in the press release, study co-author Robert Weiss, PhD, professor of biostatistics at the Fielding School, said, “To the best of our knowledge, this PrEP Calculator is the first of its kind to be based on real-world data. We hope that our PrEP calculator will allow more [men who have sex with men (MSM)] to make a more informed decision before deciding whether or not PrEP is right for them.”

Over the course of five years—from January 2009 to June 2014—a wealth of data pertaining to a number of different behavioral risk factors for HIV was collected at each client at the Los Angeles LGBT Center. According to the press release, using behavioral data and HIV test results, the center personnel determined what characteristics distinguished MSM who had been HIV-negative prior to when the study started but afterward, in a follow-up visit, ended up testing positive for the virus from those who remained HIV-negative throughout the follow-up visits. The researchers then used this data to create a “HIV-risk algorithm, which they use as a standardized mechanism for recommending PrEP” to the center’s clients.

The researchers asked questions that address a number of risk variables that they felt that the guidelines do not cover, such as: substance abuse, age, race/ethnicity, the amount of sexual partners, as well as “partner-level factors.”

They found that about half of the individuals who used the calculator (51%) had a risk score of five or more and they deducted that if these individuals were given PrEP, and consistently adhered to their treatment regimens, a whopping 75% of infections could actually be prevented during follow-up.

Using their study’s findings, the researchers developed their risk calculator, a tool that consists of 13 questions that include the aforementioned variables. After individuals select their answers, the tool calculates their level of risk. The researchers hope to find out if those who are at high risk, particularly MSM, find the tool particularly useful in helping them figure out if they should take PrEP or not.

“The findings from this study will allow MSM to determine their overall risk for HIV based on their own data and previous data collected at the Los Angeles LGBT Center. Ultimately, this HIV risk score can be used by the client to determine if PrEP is right for them,” said lead author Matthew Beymer, PhD, a postdoctoral scholar in the department of medicine, division of infectious diseases, at the David Geffen School of Medicine at UCLA, in the press release.

Dr. Beymer also noted a few limitations of this tool. Because it was created using data related to both gay and bisexual men in Los Angeles, heterosexual and transsexual individuals, injection drug users, men who do not have HIV but who have been in relationships with men who do, or even those living outside of Los Angeles may not find it reliable, according to the website. However, despite these limitations, a number of high risk individuals now have another tool in their arsenal that will provide them with recommendations specific to their lifestyle, that can advise them on if they should take PrEP, a regimen that reduces the chances of acquiring a virus that continues to claim a number of lives every day.