Mapping Pathways is a multi-national project to develop and nurture a research-driven, community-led global understanding of the emerging evidence base around the adoption of antiretroviral-based prevention strategies to end the HIV/AIDS epidemic. The evidence base is more than results from clinical trials - it must include stakeholder and community perspectives as well.

28 October 2011

Mapping Pathways So Far: The Literature Review

 * Original content from our Mapping Pathways blog team

“People are very excited about these prevention strategies, but there’s not a lot of empirical evidence out there on how to implement them, or even whether they should be implemented.”

An important part of the Mapping Pathways project is the Literature Review (Read more about the Mapping Pathways project here). While the in-depth stakeholder interviews are a way to understand on-the-ground wisdom and expert knowledge from those in the field in South Africa, the US, and India, the Literature Review is a way to step back and identify whether there are any big-picture gaps in the evidence-base for ARV-based prevention strategies as a whole.

We checked in with Molly Morgan Jones from RAND Europe, a Mapping Pathways partner organization, to learn more about the Literature Review and some of the general trends that are emerging from her research so far.

MP: Please introduce yourself and tell us a bit about what you do.

MMJ: I study innovation and technology policy at RAND Europe, which is a non-profit organisation that works to improve public policy and decision-making through objective research and analysis. By innovation and technology policy I mean that I explore the way governments or institutions look at or support the translation of  research into new ideas or new technologies that society can make use of. I work across a range of sectors, but have a particular interest in biomedical innovation.

MP: How does this relate to PrEP and other ARV-based prevention strategies?

MMJ: I see ARV-based prevention strategies as a biomedical innovation in the way that we use drugs to fight existing diseases. It’s an innovation in how we can use existing technologies (ARVs) in a new way to approach the HIV epidemic.  Of course, innovation is very context dependent; an innovation relevant to one society is not relevant to another. In the US, you have a completely different healthcare system than in Africa and India. In South Africa, you have a very different kind of epidemic than in other places. So it’s critical to understand the wider social, cultural, and economic contexts in which innovation happens. In other words, we need to understand the system of actors, individuals, government bodies, NGO’s, and institutions in each country – all the different people and bodies that support the way innovations happens - and think about what that means in the context of ARV-based prevention strategies.

People are very excited about these prevention strategies, but there’s not a lot of empirical evidence out there on how to implement them, or even whether they should be implemented. We need to understand more before we can start thinking about putting money behind these strategies. Mapping the existing evidence-base, understanding what empirical evidence is out there, and identifying what research gaps exist that still need to be filled is where the Mapping Pathways project comes in. Through the stakeholder interviews and the Literature Review, we are trying to understand what are the needs of people in particular communities, and what evidence do they need to help them make these important decisions about how to use these prevention strategies.

MP: What exactly is the Literature Review? What outputs can we expect from it? How is it going to help in bringing more clarity to some of the questions or issues surrounding ARV-based prevention strategies?

MMJ: As far as we are aware, the Literature Review is the first, comprehensive big-picture review of all the material published on ARV-based prevention strategies so far. At its most basic level, it is a way to identify the gaps in the existing research base on ARV-based prevention strategies. To our knowledge nothing like this has been done before, and we are still in the midst of completing the review. Once completed, we will produce a detailed map and analysis of how the literature on ARV-based prevention strategies breaks down by strategy (PrEP, PEP, TLC+, Microbicides), what kinds of studies are being done, what studies still need to be done, and what gaps need to be filled in the evidence base before communities can move forward on this innovation.

In order to do this, we systematically review everything that has been published to date on this particular topic. First we found over 4,000 articles by using what are called ‘keywords’ to search academic databases. We then went through all of these and using a set of inclusion criteria, narrowed them down to the 422 that are the most relevant. These are the articles that are helping us learn about the different ARV-based prevention strategies, their effectiveness, their efficacy, in other words whether they work at a biological level to prevent transmission or infection, their cost-effectiveness, their impacts on public health, and their wider social, economic, political and clinical implications. By next month, we’ll be able to provide information about the state of the evidence base which is relevant to the US, India, and South Africa. Once the review is completed, we’ll be publishing papers on our findings and presenting our conclusions to the wider HIV prevention community. In fact, two of our abstracts have already been accepted at ICASA, where we will be presenting the findings of the Literature Review for the first time (read the Mapping Pathways blog post about ICASA here).

We are hoping that the Literature Review will serve as a great resource for the wider community. It is not just a comprehensive database of relevant information, but it is also a catalyst for new research that will help us think about how we can incorporate these new innovations into our existing health systems and structures, if at all.

MP: Even though this is still very preliminary, could you share some general trends you’re finding from reviewing all this information? What are some of the big research gaps that need to be filled?

MMJ: Well, we now have this great map about what literature exists, how it breaks down by strategy, and what kinds of studies are being done. We’re spending a lot of time now reviewing the articles in more detail, but broadly speaking we’re finding that from the 400+ articles we’ve identified, the most are on microbicides and PEP (over 100 for each) and slightly less are on TLC+ and oral PrEP prevention strategies.  Even though we’re still in the process of completing the review, we’re observing that most of the literature is evidence-based commentary or literature reviews like ours about specific strategies. The commentary articles are about people expressing opinions or commenting on what’s out there and using existing evidence to support their argument for or against the various ARV-based preventions strategies. Another trend we’re seeing is that it looks like the majority of this literature seeks to evaluate or comment on the efficacy and effectiveness (in a clinical or economic sense) of these strategies. Yet, there isn’t much data out there on new studies, new trials or new evidence.

There also aren’t many cost studies on these strategies, and those that have been done are mostly on PEP (which makes sense since PEP has been around a lot longer, and studies have shown that it is effective). So, we’re looking at the cost studies that have been done and are seeing what can be learned from them to develop new studies for the other strategies. Another interesting finding is that epidemiological modelling studies have mostly been done on TLC+, but there aren’t many for PEP, PrEP, and microbicides. These kinds of studies try and estimate what the future HIV/AIDS epidemic would look like if a given ARV-based prevention strategy was introduced and how much money it might cost over time. Such predictive efforts have to be based on many different assumptions, though, and there is real variation between the studies which we’re looking at.

So we’re going to use these types of observations from the review to generate new research ideas for phase 2 of the Mapping Pathways project. For example, we might be doing modelling of our own in the next phase, or conducting cost studies.

It’s really critical we know what research is and is not being done, what evidence does and does not exist, so that we have a solid understanding of the implications of these technologies in various social, economic, cultural, and political contexts that exist in different countries. It’s only then that we can begin to think about investing in them and the best ways to implement them. If we don’t have this solid foundation of knowledge, we run the risk of the innovations in ARV-based prevention strategies not being successful


[Content that is linked from other sources is for informational purposes and should not construe a Mapping Pathways position.]

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