Gender, Racial, and Ethnic and Inequities in Receipt of Multiple National Institutes of Health Research Project Grants.

Importance: Diversity in the biomedical research workforce is essential for addressing complex health problems. Female investigators and investigators from underrepresented ethnic and racial groups generate novel, impactful, and innovative research, yet they are significantly underrepresented among National Institutes of Health (NIH) investigators. Objective: To examine the gender, ethnic, and racial distribution of super NIH investigators who received 3 or more concurrent NIH grants. Design, Setting, and Participants: This cross-sectional study included a national cohort of NIH-funded principal investigators (PIs) from the NIH Information for Management, Planning, Analysis, and Coordination (IMPAC II) database from 1991 to 2020. Exposures: Self-identified gender, race and ethnicity, annual number of NIH grant receipt, career stage, and highest degree. Main Outcomes and Measures: Distribution of investigators receiving 3 or more research project grants, referred to as super principal investigators (SPIs), by gender, race, and ethnicity. Results: Among 33 896 investigators in fiscal year 2020, 7478 (22.01%) identified as Asian, 623 (1.8%) as Black, 1624 (4.8%) as Hispanic, and 22 107 (65.2%) as White; 21 936 (61.7%) identified as men; and 8695 (35.3%) were early-stage investigators. Between 1991 and 2020, the proportion of SPIs increased 3-fold from 704 (3.7%) to 3942 (11.3%). However, SPI status was unequal across gender, ethnic, and racial groups. Women and Black PIs were significantly underrepresented among SPIs, even after adjusting for career stage and degree, and were 34% and 40% less likely than their male and White colleagues, respectively, to be an SPI. Black women PIs were the least likely to be represented among SPIs and were 71% less likely to attain SPI status than White men PIs (adjusted odds ratio, 0.29; 95% CI, 0.21-0.41). Conclusions and Relevance: In this cross-sectional study of a national cohort of NIH-funded investigators, the gender, ethnic, and racial gaps in receipt of multiple research project grants among NIH investigators was clearly apparent and warrants further investigation and interventions.