Preinjury warfarin use among elderly patients with closed head injuries in a trauma center.

BACKGROUND: This study aimed to determine the impact of warfarin use on the severity of injury among elderly patients presenting with closed head injuries.
METHODS: A cohort of patients 55 years of age or older with closed head injuries taken to a tertiary trauma center between April 1993 and March 2001 was retrospectively identified. Patient characteristics, mechanism of injury, type and severity of injury, and hospital survival data were obtained from the trauma registry. Each case then was reviewed for completeness of information, assessment of preinjury warfarin use, and comorbidity.
RESULTS: Among the 384 patients presenting with closed head injuries, 35 (9%) were receiving warfarin before their trauma. As compared with nonusers, anticoagulated patients had a higher frequency of isolated head trauma (54% vs. 32%; p = 0.008), more severe head injuries (65.7% vs. 44.1%; p = 0.02), and a higher rate of mortality (40% vs. 21%, p = 0.01). These associations remained evident even after population differences in age, gender, comorbidities, and mechanism of injury were taken into account. Indeed, according to multivariate logistic regression models, warfarin use was associated with a statistically significant risk of death (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.22-6.12), statistically significant odds for more severe head injury (OR, 2.39; 95% CI, 1.10-5.17), and odds for isolated head injury that almost reached statistical significance (OR, 1.79; 95% CI, 0.82-3.90).
CONCLUSIONS: Among patients 55 years of age or older who present with closed head injury, the use of warfarin before trauma appears to be associated with a higher frequency of isolated head trauma, more severe head trauma, and a higher likelihood of death. The findings of this retrospective study support the concern about the adverse effects of anticoagulants in cases of head trauma.