National Institutes of Health Clinical Research Funding and All-Cause In-Hospital Traumatic Brain Injury-Related Mortality

Introduction Higher federal research funding levels may improve patient outcomes. We examined this relationship between traumatic brain injury (TBI) funding and all-cause in-hospital TBI-related mortality. Methods Using an ecological series analysis, we examined the linear trend in both clinical TBI research funding in year 2000 United States dollars ($) (National Institutes of Health [NIH] RePORTER) and in-hospital isolated TBI mortality among patients aged 15 and older (National Trauma Data Bank [NTDB], TBI-related ICD-9 or ICD-10 code, abbreviated head injury score >2 and body region score <2 with ICU admission) between 2007-2015 with data from centers contributing all years of data for the study period. Linear regression was used to assess the relationship between mortality rate and total funding, lagged one to three years, both overall and within ten-year age groups. Results The mean annual NIH-TBI research funding was $64.36 million (lowest: 2008; $48.79 million, highest: 2015; $71.42 million). 192,597 encounters of patients 15 years and older, predominantly male (67.5%) and with polytrauma (59.9%), were included. There was no statistically significant reduction in in-hospital TBI-related mortality (14.15% in 2007 to 13.36% in 2015) for the cohort overall, but the mortality rate decreased for patients over 55 years. The greatest mortality reduction occurred in patients 85 years and older (-62.35, 95% CI -92.45-32.25), followed by patients 75-84 years (-44.41, 95% CI -61.72, -27.09), patients 65-74 years (-47.60, 95% CI -67.39, -27.81), and patients 55-64 years of age (-15.15, 95% CI -27.59, -2.72). During the study period, annual NIH funding for TBI varied from the lowest level of $48.79 million (in 2007) to the highest level of $77.34.43 million (in 2005). There was no association between funding in the previous three years and the in-hospital TBI-related mortality rate. Conclusion This study found a variable pattern in NIH funding for clinical TBI research and a contemporaneous reduction in moderate-severe TBI-related deaths only for those aged 55 years and older, but no association between funding and mortality.