Does NIH funding differ between medical specialties? A longitudinal analysis of NIH grant data by specialty and type of grant, 2011-2020

Objectives Differences in National Institutes of Health (NIH) funding between specialties may affect research and patient outcomes in specialties that are less well funded.The aim of this study is to evaluate how NIH funding has been awarded by medical specialty. This study assesses differences and trends in the amount of funding, by medical specialty, for the years 2011-2020, via a retrospective analysis of data from the NIH RePORTER (Research Portfolio Online Reporting Tools Expenditures and Results). Study design Longitudinal cross-sectional study Setting NIH RePORTER data from 2011 to 2020 for awarded NIH grants (F32, T32, K01, K08, K23, R01, R03, R21, U01, P30) in the following medical specialties: anaesthesiology, dermatology, emergency medicine, family medicine, internal medicine, neurology, neurosurgery, obstetrics and gynaecology, ophthalmology, orthopaedic surgery, otolaryngology, pathology, paediatrics, physical medicine and rehabilitation, plastic surgery, psychiatry, radiation-diagnostic/oncology, surgery, and urology. Participants NIH grant awardees for the years 2011-2020 Intervention None Primary and secondary outcome measures The following measures were studied: (1) number of grants by specialty, (2) number of grants per active physician in each specialty, (3) total dollar amount of grants by specialty, (4) total dollar amount of grants per active physician in each specialty and (5) mean dollar amount awarded by specialty for each grant type. We investigated whether any of these measures varied between medical specialties. Results In general, internal medicine/medicine, psychiatry, paediatrics, pathology and neurology received the most grants per year, had the highest number of grants per active physician, had the highest total amount of funding and had the highest amount of funding per active physician, whereas fields like emergency medicine, plastic surgery, orthopaedics, and obstetrics and gynaecology had the lowest. The mean dollar amount awarded by grant type differed significantly between specialties (p value less than the Bonferroni-corrected alpha=0.00029). Conclusions NIH funding varies significantly between medical specialties. This may affect research progress and the careers of scientists and may affect patient outcomes in less well funded specialties.