Research-targeting, spillovers, and the direction of science: Evidence from HIV research-funding

HIV/AIDS has been a major focus for research funders. The US National Institutes of Health (NIH) alone has spent over $70bn on HIV/AIDS. Such investments ushered in antiviral drugs, helping to reverse a rapidly growing HIV/AIDS pandemic. However, the idea that research can deliver unexpected benefits beyond its targeted field, in fact, predates HIV/AIDS to at least Vannevar Bush’s influential 1945 report. Cross-disease spillovers – research investments that yield benefits beyond the target disease – remains unexplored, even though it could inform both priority-setting and calculations of returns on research investments. To this end, we took a sample of NIH’s HIV grants and examined their publications. We analyzed 118,493 publications and found that 62% of these were spillovers. We used Medical Subject Headings (MeSH) terms assigned to publications to explore the content of these spillovers, as well as to corroborate non-spillovers. We located spillovers on a network of MeSH co-occurrence, drawn from the broader universe of biomedical publications, for comparison. We found that HIV spillovers were unevenly distributed across disease-space, and often in close proximity to HIV (60% local; 40% remote). We further reviewed 1,000 grant–publication pairs from a local sample and 1,000 pairs from a remote sample. For local spillovers, a quarter seemed to be unexpected, on the basis of their grant description; for remote spillovers, that proportion increased to one third. We also found that the NIH funding institutes whose remits were most closely related to HIV/AIDS were less likely to produce spillovers than others. We discuss implications for theory and policy.