TY - JOUR T1 - Female grant applicants are equally successful when peer reviewers assess the science, but not when they assess the scientist JF - bioRxiv DO - 10.1101/232868 SP - 232868 AU - Holly O. Witteman AU - Michael Hendricks AU - Sharon Straus AU - Cara Tannenbaum Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/03/02/232868.abstract N2 - Background Previous research shows that men often receive more research funding than women, but does not provide empirical evidence as to why this occurs. In 2014, the Canadian Institutes of Health Research (CIHR) created a natural experiment by dividing all investigator-initiated funding into two new grant programs: one with and one without an explicit review focus on the caliber of the principal investigator.Methods We analyzed application success among 23,918 grant applications from 7,093 unique principal investigators in a 5-year natural experiment across all investigator-initiated CIHR grant programs in 2011-2016. We used Generalized Estimating Equations to account for multiple applications by the same applicant and an interaction term between each principal investigator’s self-reported sex and grant programs to compare success rates between male and female applicants under different review criteria.Results The overall grant success rate across all competitions was 15.8%. After adjusting for age and research domain, the predicted probability of funding success in traditional programs was 0.9 percentage points higher for male than for female principal investigators (OR 0.934, 95% CI 0.854-1.022). In the new program focused on the proposed science, the gap was 0.9 percentage points in favour of male principal investigators (OR 0.998, 95% CI 0.794-1.229). In the new program with an explicit review focus on the caliber of the principal investigator, the gap was 4.0 percentage points in favour of male principal investigators (OR 0.705, 95% CI 0.519- 0.960).Interpretation This study suggests gender gaps in grant funding are attributable to less favourable assessments of women as principal investigators, not differences in assessments of the quality of science led by women. We propose ways for funders to avoid allowing gender bias to influence research funding.Funding This study was unfunded. ER -