The effect of preinjury warfarin use on mortality rates in trauma patients: a European multicentre study

OBJECTIVE: To define the relationship between preinjury warfarin use and mortality in a large European sample of trauma patients. METHODS: A multicentred study was conducted using data collated from European (predominately English and Welsh) trauma receiving hospitals. Patient data from the Trauma Audit and Research Network database from 2009 to 2013 were analysed. Univariate and multivariate logistic regression was used to estimate OR for mortality associated with preinjury warfarin use in the whole adult trauma cohort and a matched sample of patients comparable in terms of age, gender, GCS, pre-existing medical conditions and injury severity. RESULTS: A total of 136 617 adult trauma patients (2009-2013) were included, with 499 patients reported to be using warfarin therapy at the time of trauma. Preinjury warfarin use was associated with a significantly higher mortality rate at 30 days postinjury compared with the non-users. Following adjustment of age, injury severity and GCS, preinjury warfarin use was associated with increased mortality in trauma patients (adjusted OR 2.14; 95% CI 1.66 to 2.76; p<0.001). In the matched subset, 22% of warfarinised trauma patients died compared with 16.3% of non-warfarinised trauma patients with comparable age, injury severity and GCS (adjusted OR 1.94; 95% CI 1.25 to 3.01; p=0.003). CONCLUSIONS: Preinjury warfarin use has been demonstrated to be an independent predictor of mortality in trauma patients. Clinicians managing major trauma patients on warfarin need to be aware of the vulnerability of this group.