While clinical trials have demonstrated the efficacy of treatment as prevention, pre-exposure prophylaxis and vaginal microbicides, researchers and policy makers lack clarity on the conditions that affect the effectiveness of these strategies in the ‘real world’. Local factors, such as available resources, affected populations, the wider health system and the cultural context are crucial but poorly understood, according to stakeholders.
“Looking at the exact same data and reports, stakeholders in India, South Africa and the US often came to very different conclusions about their implications and relevance”, say the authors of the Mapping Pathways report, published this week. This may mean that strategies are implemented in very different ways – or not at all – in different parts of the world.
As part of a wider project, the researchers interviewed 41 stakeholders (9 in India, 13 in South Africa and 19 in the US) and conducted two further focus groups in the US. Stakeholders had influence on HIV/AIDS prevention policy in their country, through their role in clinical care, policy, research or advocacy. Interviews explored participants’ perceptions of antiretroviral-based prevention strategies – testing, linkage to care and treatment; pre-exposure prophylaxis (PrEP) and microbicides.
Questions of costs and resources were often central to participants’ perceptions of the relevance of these strategies. Because many people with HIV cannot currently get the drugs they need, it was hard for stakeholders to justify delivering ARVs to HIV-negative people, even those at high risk. Many did not accept that cheaper prevention options, such as condoms, would not be sufficient.
“We already have a shortage of resources… And now we’re talking about a massive roll-out in negatives? [I’ve been] one of the people who was centrally involved in arguing the case for the affordability of ARVs in South Africa in the 2000s, but even [I] think there just aren’t the resources – it’s inconceivable.”
This applied in all three countries, and in relation to each prevention method. Many were concerned about diverting resources away from existing behavioural prevention approaches, as explained by this American respondent.
“This is ridiculous. Only 2-3% of the AIDS portfolio is spent on prevention. Prevention money continues to go down. Switching funds [to treatment as prevention] would result in total elimination of prevention funds.”
Especially in South Africa, the concern was not just about financial resources, but the logistical capacity, human resources and political backing that a health system would require to deliver these interventions.
While Indian stakeholders were generally the most sceptical about the relevance of ARV-based strategies, they had some interest in 'treatment as prevention' as it was perceived to enable better access to HIV treatment (that is needed anyway) for individuals with HIV.
Across all countries, there was generally more support for this strategy than the other two.
Stakeholders from the United States were consistently the most positive about all three ARV-based prevention strategies and least worried about the nature of the science. They had questions about available resources, but less concern about applicability and generalisability of the findings from clinical trials. Whereas most American stakeholders supported changes in treatment guidelines following the HPTN 052 trial, Indian and South African respondents did not.
The greatest scepticism and uncertainty was expressed in relation to PrEP. Respondents who felt it had applicability saw it as a tool for high-risk groups, but there were disagreements about which populations should be included, particularly in the light of disappointing results with young African women. And there were concerns about how clinicians could identify and reach the individuals at greatest risk.
“I am sceptical about how to use the PrEP results. I think the guidelines could be modified to include the examples above (abused women, sex workers, couples wanting to conceive, MSM who self- identify as high risk) – but how do you put that in the guidelines – at the discretion of the clinician?”
“In an Indian culture that still struggles to accept condoms, it would be difficult to get the general population to accept PrEP. While risk categories based on global norms are feasible to define and accept, it will be hard for an individual to accept that he or she is ‘high risk’ and should take this treatment.”
While participants were generally interested in vaginal microbicides because of their potential to empower women, the mixed results of the CAPRISA 004 trial raised a number of question about adherence and the very high rate of new infections seen in the study. Respondents from South Africa (where CAPRISA 004 was conducted) also raised questions about how microbicides should be described and presented.
“The only way there will be more of a chance of them ever being taken up by communities is if they are marketed as a sex toy or lubricant. If you call them microbicides, you’ll sell 3 in 20 years... They now need to be handed over to a marketing company to consider how to advertise them as a sex toy. But [I] wonder how this could ever be done in practice. Grumpy old nurses are funny about condoms so [they] would struggle with marketing a product as sex enhancing.”
In relation to all methods, Indian stakeholders spoke of mitigating local circumstances or politics as major obstacles to adoption. They wanted to ground knowledge in their own setting and were often unwilling to accept outside views or study results at face value.
The available data on the prevention interventions come from randomised control trials (RCTs), which focus on efficacy rather than effectiveness. RCTs provide evidence that is robust, but rather narrow, the authors say.
Efficacy refers to whether the strategy has a beneficial effect in a clinical trial setting, which typically has extra resources and recruits a slightly atypical group of individuals to take part. Effectiveness refers to evidence about whether the strategy works in day-to-day medical practice. Here, variables such as individuals’ risk behaviour, adherence, resources and health systems can effect whether the strategy works or not in different settings.
“Context matters,” say the authors. Future studies “need to explore how the strategy would be implemented in a local context and what social arrangements are needed to support it,” they say. The research found that without such data, many stakeholders (especially in India and South Africa) would be unwilling to recommend any implementation of treatment as prevention, PrEP or microbicides.
Jones MM et al. Mapping Pathways: Developing evidence-based, people-centred strategies for the use of antiretrovirals as prevention. RAND Europe, 2013. (Full text available here).