July 22, 2015

The pros and cons of PrEP: trial volunteers recount their experience of the ADAPT study

Written by Gus Cairns

This article originally appeared on NAM’s website.

The reasons whether or not people come forward for pre-exposure prophylaxis (PrEP) or take it once prescribed are likely to be very mixed, and dependent as much on local political and cultural beliefs as they are on more personal factors like relationship status, the Eighth International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention (IAS 2015) heard yesterday.

The HPTN 067 (ADAPT) study is a phase II open-label study of Truvada PrEP based in three world cities (Cape Town, Bangkok and Harlem, New York). It aims to evaluate the ease of use and feasibility of three different PrEP regimens: daily dosing, timed dosing (meaning two doses a week plus an extra dose two hours after sex, if it happens), and event-driven dosing, which means one dose 2-24 hours ahead of anticipated sex and one two hours after, if it happens.

For the data on adherence, pill usage and HIV infections, see this report.

Each of the three city studies also had qualitative studies attached to it so that participants could relate their experience of taking PrEP.

Cape Town

In Cape Town, 18 of the 179 women involved gave in-depth interviews to the researchers – six in each regimen arm, three in the first half of the study and three near its end. There were also six focus groups of seven participants each. Thus 60, or about a third of study participants, gave qualitative feedback.

Rivet Amico of the University of Michigan, who headed the qualitative study, said that attitudes of participants in this and in other prevention studies ranged over a whole spectrum from full endorsement to complete distrust. Adherence (the percentage of pills taken) and persistence (the length of time participants stayed in the study as active participants) were likened to these attitudes. She said that attitudes towards the study varied from complete distrust and avoidance of pill-taking to empowerment and acting as a champion for PrEP.

Factors that might particularly influence African participants included ‘Ubuntu’, the belief that the worth of an individual depends on the contribution they make to their surrounding community: the trial would be weighed against standards of community usefulness.

Scepticism about the trial was not necessarily unhealthy: participants might be well aware that a scientific trial’s outcome was uncertain and might have fears of taking PrEP and distrust of the integrity and trustworthiness of the trial and its researchers. These could be amplified or diminished by the influence of the community and especially by other PrEP champions or anti-PrEP advocates.

Distrust was more common in this and other PrEP studies in South Africa than in some other settings because participants were more likely to join the trial for other motives such as the medical benefits it offered, while actually not believing in the benefit of PrEP. Such participants could even act as advocates against PrEP. “I will never drink [take] these pills because I don’t trust them” said one.

Cautious exploration was the term best suited to the next category, who weren’t sure what they thought about PrEP and could be swayed by arguments for or against it, with resulting irregular adherence. “I was getting confused and pressured because I did not know whether to continue to take tablets or not” said one participant.

Provisional acceptance characterised the next group, who were motivated to try to take PrEP. Their persistence was good but they often found actually remembering to take the pills challenging: they were characterised more by a determination to be good participants than by a feeling of empowerment: “I wouldn’t do that [i.e. not take the tablets] because I want to see if these pills really, really work” said one.

Ownership was the best word to describe the attitude of the fourth group, who did not just feel like enrolled participants, but like partners in a joint enterprise. They often acted as champions for PrEP and saw it as their job to combat negative perceptions and beliefs. One factor that African participants in PrEP trials, in particular, have cited as a barrier to adherence is the assumption by family and friends that someone taking an antiretroviral pill must have HIV. One participant described combating such remarks: “And I said, ‘look here, ask me. And don’t you dare say I have HIV, telling everyone in this shop. We are doing research here’.”

Rivet Amico commented that depending on where they were in this spectrum, the usual adherence counselling strategies might help but might also have counterproductive effects. If someone was already distrustful of the trial, then asking them to address barriers to adherence might only entrench distrust: beliefs needed to be addressed rather than difficulties. Equally, people who felt like partners and advocates might feel disempowered and talked-down to if constantly reminded of the importance of adherence: instead, counselling might concentrate on supporting their advocacy. “Don’t assume people enter a study ‘neutral’”, Amico said.

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