A new study suggests there might be a very high bar for acceptance of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM), transgender females and female sex workers. The study, published in the May 5 issue of the International Journal of STD & AIDS, found that PrEP would need to be cheap, highly effective and used only intermittently before these groups would want to use it.

Ever since the news broke in late 2010 that a Truvada (tenofovir plus emtricitabine) PrEP regimen could reduce new HIV infections by 44 percent or more, experts and community members have been questioning how to safely roll out this new prevention intervention and whether people would even want to use it. Scientists and public health experts had assumed that PrEP—whereby HIV-negative people take antiretroviral (ARV) medication to prevent becoming infected—would likely work, but they remained uncertain how to use it if studies confirmed its efficacy.

Subsequently, researchers with the University of California in Los Angeles partnered with researchers at the Cayetano Heredia University School of Public Health in Lima, Peru, to begin answering this key question.

“Just a few months ago, we learned that PrEP can prevent HIV infection, but it has not been deployed on a large scale yet and is a topic of debate in the HIV-prevention research community,” said Jerome Galea, Latin America regional director for the UCLA Program in Global Health and one of the study's co-investigators.

Galea and his colleagues turned to the same populations that were included in the original iPrEx PrEP study—mostly Peruvian MSM and female transgenders—plus female sex workers and presented them with a number of scenarios to determine what factors would influence their likelihood to use PrEP.

Specifically, Galea's team assessed PrEP acceptability using two methods—focus groups and conjoint analysis—that product manufactures frequently use to figure out how to market a new consumer product. With conjoint analysis, people are given a range of various related options—such as varying price—to see what factors most influence their choices.

“This is the first study of its kind to apply this specific market research technique to understand what the ‘consumers' of PrEP valued most about this method of prevention,” Galea said.

For the study, the researchers divided 45 participants into seven groups of four to eight individuals, with each participating in both the focus groups and the conjoint analysis exercise.

In the focus groups, researchers looked for patterns of knowledge about PrEP, and what participants believed would most influence their decisions—and that of their peers—to use PrEP. In the coinjoint analysis, participants were asked to choose between a range of options that included out-of-pocket costs, efficacy, side effects and duration of use and dosing.
 
The conjoint analysis revealed that a low out-of-pocket cost was the most important factor to the participants.

“While we expected cost to be an important factor, we were surprised that it was more important than the ability of the product to actually prevent HIV infection,” Galea said.
 
Taken together, people said that they would be most likely to use PrEP if it was low cost, had 95 percent efficacy, no side effects, and could be taken just before having sex. Given that PrEP must be taken daily and only approached 95 percent efficacy in people whose blood levels confirmed that they took it regularly—and given that another recent PrEP trial in heterosexual couples ended for lack of ability to show efficacy—these desires appear unrealistic.

Because the study was small and included only a narrow subsection of those to whom PrEP would likely be offered, Galea and his team are recommending that further research is needed.

“We cannot generalize our findings to all persons at risk for HIV, in Peru or elsewhere,” he said. “But we do propose it as a model for future exploration of the topic, now that oral PrEP has been shown to work but has not yet been scaled up for widespread use.”