The study finds that that career stage and institutional resources influence the gap in the number of submissions by black and white researchers. However, the research revealed that black applicants as a group are more likely to propose research topics that are less likely to be funded.

"These results were a surprise -- research topics that were less funded are vitally important," said NIH Director Francis S. Collins, MD, PhD. "We need to understand whether there is an intrinsic bias against such topics by reviewers, or whether the methodologies used in those fields of research need an upgrade."

The study identified disparate outcomes between black and white scientists at three decision points:

• selection for discussion,
• impact score assigned by the review panel
• research topic choice (which is a previously unstudied factor)

Subject matter experts from the scientific community showed a preference for research topics that tend to have methodologies that are highly controlled with very precise outcomes. Black applicants were more likely than white applicants to propose research topics that receive awards at a lower rate, such as community or population-level research. Health disparities research and patient-focused interventions were among the topics with the lowest success rates. Importantly, white researchers also experienced lower award rates in these topic areas, although less so than black researchers.

The NIH has made many efforts to close this funding gap first identified in 2011. This new research identifies opportunities for interventions that could bolster NIH's scientific workforce diversity efforts underway, such as the Diversity Program Consortium and the MOSAIC program.

"The underlying explanation for the phenomenon observed in this paper is complex and requires further study to determine how best to intervene," said Hannah A. Valantine, MD, NIH's Chief Officer for Scientific Workforce Diversity. "We will continue to explore the causal factors behind the R01 funding gap to add to NIH's broader scientific workforce diversity program."