Population-based study of the risk of in-hospital death after traumatic brain injury: the role of sepsis.

BACKGROUND: Traumatic brain injury (TBI) accounts for the largest proportion of injury-related deaths and disability in the United States. The proportion of TBI-related deaths that occur after admission in a hospital remains high despite improvement in medical technology. We provide findings on the risk factors of in-hospital death and demonstrate the risk associated with sepsis occurring in the hospital environment.
METHODS: Population-based retrospective cohort study of 41,395 patients with TBI from all nonfederal hospitals in South Carolina, 1998 to 2009. TBI was ascertained by International Classification of Diseases-9th Rev.-Clinical Modification codes of 800 to 801, 803 to 804, 850 to 854, and 959.01. Observation was censored at the 120th day. Days elapsing from the date of injury to date of death established the survival time (T). Cox regression was used to examine the risk of death, whereas Kaplan-Meier survival curves compared survival probabilities across time.
RESULTS: Sepsis was independently associated with risk of in-hospital death with hazard ratio of 1.34 (p < 0.001). Severity of TBI was the strongest risk factor with hazard ratio of 4.97 (p < 0.001). Nearly 90% of patients with sepsis were identified with one of the nosocomial etiologies included in the analyses compared with 7% of patients without sepsis (p < 0.001). The survival probabilities were significantly lower for persons with sepsis compared with those without (log-rank test p < 0.001).
CONCLUSION: Sepsis occurring in the hospital environment and associated with nosocomial etiologies is a strong risk factor for in-hospital death after TBI. Reducing the risk of infections and subsequent sepsis through adherence with infection control measures is a critical step to reduce in-hospital deaths among patients with TBI.