Each NIH Institute and Center (IC) has its own leadership and, to some extent, policies, practices, and priorities. Furthermore, each receives a separate appropriation from Congress. Because of these influences, factors of considerable interest to the scientific community vary from one IC to another.
One such factor is the success rate for R01 applications. Note that "success rate" is related to but different from "payline". The success rate is the number of awards made in a given fiscal year divided by the number of applications reviewed in that year. The number of applications reviewed includes both scored and unscored applications but applications for the same grant (e.g. an A0 and an A1) reviewed in the same year are only counted once. The payline is a percentile threshold that some ICs use in a manner that almost all applications that score better than the payline are funded. This difference has been the source of much confusion over the years. Rock Talk, NIGMS, NIAID, and likely other ICs) have posted explanations.
Success rate data are available through NIH RePORT. The data for FY 2014 (which ended September 30, 2014) are not yet available. For FY 2013, the results for R01 success rates are as follows:
NIH Overall 17%
Note that these range from 4% to 28%. Some ICs have rather specialized missions and do not accept many R01 applications. These include NCCAM, NCATS, NHGRI, NIMHD, NINR, and NLM. These will be excluded from the rest of this analysis.
What characteristics of the ICs correlate with R01 success rate? One possibility is the overall size of the IC budget. Success rates are shown below with the ICs ordered in terms of budget size.
There is, in fact, a negative correlation (correlation coefficient -.39) such that larger ICs tend to have lower R01 success rates.
An alternative is the IC investment (in $) in R01s. Success rates are plotted below with the ICs ordered in terms of the size of the R01 investment.
While there is an increasing trend for the ICs with a smaller R01 investment, the overall correlation is again negative (correlation coefficient -0.23).
A final characteristic is the percentage of the IC budget committed to R01 funding. These percentages ranged from 23.6% to 58.3% in FY2013.
A plot versus these percentages is shown below:
Here, a substantial positive correlation is observed with a correlation coefficient of 0.70.
Note that the some of the larger ICs with relatively low percentages of their budgets invested in R01s have considerable other responsibilities for infrastructure or specialized programs. Nonetheless, these data reveal one potential degree of freedom that could help mitigate the historically low R01 success rates that we are now experiencing.
Note that the overall investment in R01 equivalent grants (as a percentage of the NIH budget) has declined over the years. At the start of the doubling (FY1998), this percentage was 43.8%. At the end of the doubling (FY2003), this had declined to 37.2%. In FY2013, it stood at 34.7%.