Warfarin is Associated with Increased Intracranial Hemorrhage and Mortality in Patients with Ground Level Falls: A Retrospective Cohort Study

Abstract

Background: Fall is the number one mechanism of injury for admissions to trauma centers across the US. The use of anticoagulation therapy has also increased significantly, particularly among the older population. We hypothesized that anticoagulation with warfarin increases the risk of intracranial hemorrhage (ICH) and death after a ground level fall. Methods: A retrospective cohort of all patients admitted to a level 1 trauma center, between 2008 and 2011, after a ground level fall was identified. Warfarin use, ICH and in-hospital mortality were assessed from review of medical records. Exposure was defined as current warfarin use or an International Normalization Ratio (INR) ≥1.3. Age, gender, Glasgow Coma Scale (GCS), Injury Severity Score (ISS) and acute traumatic injuries identified on chest and extremity radiographs were evaluated. Univariate and multivariate logistic regression analyses were performed. Results/Discussion: Of the 1,535 patients admitted for ground level falls, 135 (8.8%) were taking warfarin and 16.5% had INR ≥1.3. 725 (47.2%) patients met criteria for CT head and 7.6% had an ICH. In-hospital mortality was 2.75%. Warfarin was associated with higher incidence of ICH (Crude OR 2.28; 95% CI, 1.36-3.84) and mortality (Crude OR 2.80; 95% CI, 1.31-6.00). Similarly, INR ≥ 1.3 had significant association with ICH (OR 2.14; 95% CI, 1.403.28) and mortality (OR 3.88; 95% CI, 2.04-7.40). After controlling for age and gender in logistic regression model, warfarin use and INR ≥ 1.3 continued to be independent predictors of ICH with adjusted ORs of 2.02 (95% CI, 1.19-3.44) and 2.00 (95% CI, 1.303.09) respectively. Adjusted odds ratios of mortality with warfarin use and INR ≥ 1.3, after controlling for age, gender and ISS, were 2.65 (95% CI, 1.19-5.91) and 3.75 (95% CI, 1.89-7.42) respectively. Conclusions: Warfarin use or elevated INR are associated with ICH and mortality after ground level falls. prevalence of atrial fibrillation in this patient population. Currently, atrial fibrillation affects approximately 2.2 million Americans [1]. The prevalence of atrial fibrillation increases with age, with more than 38% of patients older than 65 years of age being affected [ 2].