Researchers find the diseases with the greatest global burden aren’t the most researched

Unfortunately, it’s not too terribly surprising that diseases of the developing world don’t attract as much research attention as diseases common in wealthier countries. However, a new study not only underscores that trend, it actually found zero relationship between global disease burden and health research.

Designed to identify the reasons behind global health research disparities, the study compared the global disease burden (defined as healthy life years lost to disease or disability) of 111 diseases against relevant research articles using data from the World Health Organization and the National Library of Medicine’s biomedical journal database. From the outset, the researchers wrote that they expected to find only a weak association. But they were surprised to find no relationship at all, said lead author James Evans, director of the Knowledge Lab at the University of Chicago and an associate professor of sociology. And for randomized controlled trials and animal model studies, a higher global need was actually associated with less global research.

“We have an interest in not just thinking about global health as the ultimate outcome, but an intermediate outcome of more global health knowledge. …We need more information. We may think we know everything, but we don’t know how to treat (these diseases) in resource-poor environments,” Evans told me. “My hope is that (our findings) will fuel an already existing movement to support population health and global health initiatives.”

The study, published in the April edition of PLOS ONE, found that cancers, skin diseases and endocrine disorders, such as diabetes, are over-represented in research considering their burden; whereas, infectious parasitic disorders, respiratory infections and perinatal conditions were under-represented relative to their effect on human health. In addition to examining the relationship between burden and research, the study also considered the global market for treatment. In that case, researchers found that for every $10 billion lost to a disease or disability, the number of research articles on the disease in question rose between 3 and 5 percent.

At a local level, however, the picture is a bit different. Locally, disease burden did make a difference on research. The study found that for each 10 million disability-adjusted life years lost to a disease within a country, the number of articles published by researchers also within that country went up by nearly 74 percent. Authors Evans, Jae-Mahn Shim and John Ioannidis write that this finding “suggests that whether or not researchers and funding agencies factor global health needs into their research, the influence of local needs exerts much more influence on their work.”

So, if researchers tend to focus on diseases that they know — diseases that affect their communities — what does that mean for countries without the capacity to conduct health research? Evans and his colleagues point out that there are “striking disparities” in global health research capacity, with wealthier countries conducting the most research. Adding to the challenge is that even though some research, such as cancer research, is relevant to people in wealthy and impoverished countries, its translation into effective practice within a resource-poor environment is still missing. The study authors write:

Ultimately, this article stresses that poor populations are in double jeopardy: they experience the greatest health burdens but their diseases have been studied least and even researchers from wealthy countries often lack secure knowledge for context-relevant treatments. …A growing collection of related findings have been framed as evidence that biological factors play a role in health disparities, but they also implicate the differential relevance of health knowledge produced by biomedical research for the health of different groups. In short, the same care may not always be equal. In this way, the inequality of biomedical research that our analysis demonstrates likely understates its true inequality.

“We’ve been engaged in health extension and translation, in sending over physicians for a long time…and certainly that’s a good thing,” Evans told me. “But there’s diminishing returns to that strategy. So, I’d place my next dollar in actually helping to create and bolster a research environment in those countries.”

Of course, developing biomedical research capacity in impoverished countries is an enormous undertaking. In response, Evans said supporting a regional approach could reap some of the most effective outcomes.

“Countries that are relatively more wealthy in these regions that already have existing research infrastructures in place are where I’d place my bets, as their research would be most relevant to their neighbors,” he said. “So supporting the extension of research not just from Philadelphia, but from South Africa, from Kenya to their neighbors would provide greater returns.”

To read the full study, visit PLOS ONE.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.

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