Datahound has some very interesting analyses up regarding NIH-wide sex differences in the success of the K99/R00 program.
Of the 218 men with K99 awards, 201 (or 92%) went on to activate the R00 portion. Of the 142 women, 127 (or 89%) went on to these R00 phase. These differences in these percentages are not statistically different.
Of the 201 men with R00 awards, 114 (57%) have gone on to receive at least 1 R01 award to date. In contrast, of the 127 women with R00 awards, only 53 (42%) have received an R01 award. This difference is jarring and is statistically significant (P value=0.009).
So per my usual, I'm very interested in what the ICs that are closest to my lab's heart have been up to with this program. Looking at K99 awardees from 07 to 09 I find women PIs to constitute 3/3, 1/3 and 2/4 in one Institute and 1/7, 2/6 and 5/14 in the other Institute. One of these is doing better than the other and I will just note that was before the arrival of a Director who has been very vocal about sex discrimination in science and academia.
In terms of the conversion to R01 funding that is the subject of Datahound's post, the smaller Institution has decent outcomes* for K99 awardees from 07 (R01, R21, nothing), 08 (R01, R01, R01) and 09 (P20 component, U component, nothing, nothing).
In the other Institute, the single woman from 07 did not appear to convert to the R00 phase but Google suggests made Assistant Professor rank anyway. No additional NIH funding. The rest of the 07 class contains 4 with R01 and two with nothing. In 08, the women PIs are split (one R01, one nothing) similar to the men (2 R01, 2 with nothing). In 09 the women PIs have two with R01s, one R03 and two with nothing.
So from this qualitative look, nothing is out of step with Datahound's NIH-wide stats. There are 14/37 women PIs, this 38% is similar to the NIH-wide 39% Datahound quoted although there may be a difference between these two ICS (30% vs 60%) that could stand some inquiry. One of 37 K99 awardees failed to convert to R00 from the K99 (but seems to be faculty anyway). Grant conversion past the R00 is looking to be roughly half or a bit better.
I didn't do the men for the 2009 cohort in the larger Institute but otherwise the sex differences in terms of getting/not getting additional funding beyond the R00 seems pretty similar.
I do hope Datahound's stats open some eyes at the NIH, however. Sure, there are reasons to potentially excuse away a sex difference in the rates of landing additional research funding past the R00. But I am reminded of a graph Sally Rockey posted regarding the success rate on R01-equivalent awards. It showed that men and women PIs had nearly identical success rates on new (Type 1) proposals but slightly lower success on Renewal (Type 2) applications. This pastes over the rates of conversion to R00 and the acquisition of additional funding, if you squint a bit.
Are women overall less productive once they've landed some initial funding? Are they viewed negatively on the continuation of a project but not on the initiation of it? Are women too humble about what they have accomplished?
*I'm counting components of P or U mechanisms but not pilot awards.