Purpose: To determine factors associated with research productivity among all university radiology departments in the United States.
Materials and methods: As an observational study, this was exempt from institutional review board approval. All 47,299 radiology articles from 1996 through 2003 that were indexed in the National Library of Medicine MEDLINE database were studied. Each article was assigned a "publication impact" score based on the impact factor of its source journal. These citations were then matched, along with National Institutes of Health (NIH) extramural grant, residency, fellowship, faculty, and geographic data, to 109 individual medical school radiology departments. Raw citation count was used to measure research quantity, and aggregate publication impact was used to measure quality. Regression analyses were used to compare the relationship between the study variables and research quality and quantity measures on the departmental and individual faculty level.
Results: Finalized statistical models accounted for 75%-88% of variance in productivity. NIH funding had a significant and positive association with all measures of research productivity (P < .001), with one article associated with 167,980 dollars in funding and one publication impact unit associated with 83,271 dollars in funding. Large resident program sizes (P < .001) and the presence of fellows (P = .007) also had a significant association. Geographic region, salary, and faculty characteristics had no detectable association. Extrapolations based on these results estimated the cost of annual global radiology research at 907 million dollars, with the U.S. component at at least 417 million dollars. NIH funding accounted for 45% of the U.S. component.
Conclusion: NIH funding, resident program size, and fellow characteristics are significantly associated with academic research output.
RSNA, 2005