NIH funding longevity by gender

Abstract

Women have achieved parity with men among biomedical science degree holders but remain underrepresented in academic positions. The National Institutes of Health (NIH)-the world's largest public funder of biomedical research-receives less than one-third of its new grant applications from women. Correspondingly, women compose less than one-third of NIH research grantees, even though they are as successful as men in obtaining first-time grants. Our study examined women's and men's NIH funding trajectories over time (n = 34,770), exploring whether women remain funded at the same rate as men after receiving their first major research grants. A survival analysis demonstrated a slightly lower funding longevity for women. We next examined gender differences in application, review, and funding outcomes. Women individually held fewer grants, submitted fewer applications, and were less successful in renewing grants-factors that could lead to gender differences in funding longevity. Finally, two adjusted survival models that account for initial investigator characteristics or subsequent application behavior showed no gender differences, suggesting that the small observed longevity differences are affected by both sets of factors. Overall, given men's and women's generally comparable funding longevities, the data contradict the common assumption that women experience accelerated attrition compared with men across all career stages. Women's likelihood of sustaining NIH funding may be better than commonly perceived. This suggests a need to explore women's underrepresentation among initial NIH grantees, as well as their lower rates of new and renewal application submissions.

Keywords: NIH funding; National Institutes of Health; academia; biomedical workforce; gender disparities.

Fig. 1.

Kaplan–Meier survival plot of investigators’ sustained NIH RPG funding. The number of individuals at risk are listed below the plot, and 95% CIs are shown (Greenwood’s formula). (A) Men remained in the funding pool at slightly higher rates than women [women, n = 10,660; men, n = 24,110; MH: χ²(1) = 15.5, P < 0.001; GW: χ²(1) = 10.2, P = 0.001]. (B) Funding longevity by cohort, based on the year of first major RPG award. Recently funded investigators exited the NIH funding pool more quickly than earliest-funded investigators [1991–1995, n = 7,731; 1996–2000, n = 8,312; 2001–2005, n = 8,758; 2006–2010, n = 9,969; MH: χ²(3) = 223, P < 0.001; GW: χ²(3) = 217, P < 0.001].

Fig. 2.

Kaplan–Meier survival curves, by gender, for each cohort. The numbers of individuals at risk are below the plots, and the percentages of women and men initially funded are to the right; 95% CIs are shown (Greenwood’s formula). Results are shown by cohort based on the year of first RPG. (A) In 1991–1995, women (28.35% of the cohort) left the funding pool at a slightly higher rate than men [women, n = 2,192; men, n = 5,539; MH: χ²(1) = 6.6, P = 0.01; GW: χ²(1) = 3.9, P = 0.05]. (B) In 1996–2000, women (29.31% of the cohort) left the funding pool at slightly higher rates than men [women, n = 2,436; men, n = 5,876; MH: χ²(1) = 4.6, P = 0.03; GW: χ²(1) = 4.0, P = 0.05]. (C) In 2001–2005, women (30.71%) and men showed no statistically significant survival difference [women, n = 2,690; men, n = 6,068; MH: χ²(1) = 2.1, P = 0.14; GW: χ²(1) = 1.1, P = 0.31]. (D) In 2006–2010, women (33.52%) and men showed no statistically significant survival difference [women, n = 3,342; men, n = 6,627; MH: χ²(1) = 0.2, P = 0.68; GW: χ²(1) = 0.1, P = 0.74].

Fig. 3.

Boxplots of new project application volume, funding rates, and score percentiles, by gender and cohort. Markers indicate means; bars indicate medians. Red cohort labels indicate statistically significant gender differences (P ≤ 0.05, Wilcoxon rank-sum test, two-tailed). Outliers are not shown. (A) Women submitted slightly fewer new applications per year than men overall and within each cohort (1991–1995: women, n = 2,192; men, n = 5,539; W = 6,383,318, P < 0.001; 1996–2000: women, n = 2,436; men, n = 5,876; W = 7,802,511, P < 0.001; 2001–2005: women, n = 2,690; men, n = 6,068; W = 8,868,382, P < 0.001; 2006–2010: women, n = 3,342 men, n = 6,627; W = 11,865,699, P < 0.001). (B) While average funding rates were no different between the genders overall, women had a slightly lower funding rate in the 1991–1995 cohort (women, n = 1,551; men, n = 4,032; W = 3,235,387, P = 0.04). (C) While women and men’s average score percentiles were not statistically different overall, in the 2006–2010 cohort, women scored slightly better on average than men (women, n = 1,501; men, n = 3,175; W = 2,487,779, P = 0.02).

Fig. 4.

Boxplots of renewal project submission rates, funding rates, and score percentiles, by gender and cohort. Markers indicate means; bars indicate medians. Red cohort labels indicate statistically significant gender differences (P ≤ 0.05, Wilcoxon rank-sum test, two-tailed). Outliers are not shown. (A) Women on average submitted a lower proportion of their eligible projects for renewal than men, overall and within each cohort (1991–1995: women, n = 2,157; men, n = 5,461; W = 6,113,935, P = 0.007; 1996–2000: women, n = 2,395; men, n = 5,776; W = 7,233,755, P < 0.001; 2001–2005: women, n = 2,642; men, n = 5,965; W = 8,115,178, P = 0.02; 2006–2010: women, n = 2,572; men, n = 5,365; W = 7,124,838, P = 0.007). (B) The women’s funding rate for project renewals was significantly lower than the men’s overall and for the first three cohorts (1991–1995: women, n = 1,322; men, n = 3,581; W = 2,513,130, P < 0.001; 1996–2000: women, n = 1,380; men, n = 3,684; W = 2,668,360, P = 0.005; 2001–2005: women, n = 1,355; men, n = 3,329; W = 2,365,518, P = 0.006). (C) Women also scored less well on review overall, but this difference was not significant within any cohort.