Background This study compares clinical outcomes in patients with head trauma, taking preinjury antiplatelet drugs (aspirin, clopidogrel) and anticoagulants (warfarin).

Methods A prospective observational cohort study of prognosis in head-injured patients was undertaken in the emergency (ED) department of an adult tertiary hospital with a statewide neurosurgical service from 2008 to 2010. A convenience sample of patients taking warfarin, aspirin, clopidogrel or mixed therapy presenting to the ED with head trauma were included and followed-up over 3–18 months. Outcomes were severity of brain injury on neuroimaging, intensive care unit admission, intracranial surgery, intracranial complications, death in hospital, altered Glasgow Coma Score (GCS) on hospital discharge, and mortality and function scores on follow-up.

Results Overall, 345 patients were included in the study. Of these, 164, 70, 55 and 56 were taking aspirin, warfarin, clopidogrel and combination agents, respectively, with 250 having neuroimaging in the ED. Neuroimaging was significantly more likely to be undertaken in patients with a more urgent triage score (p<0.001), an abnormal GCS (p=0.004), older patients (p=0.039), and those taking warfarin (p<0.001). In patients receiving neuroimaging and admitted to hospital, the proportion with acute brain injury, poor hospital outcomes or overall poor outcomes were not statistically different between the agent groups.

Conclusions A high proportion of patients taking warfarin underwent neuroimaging, but brain injury and admission rates were comparable between groups. There were no significant differences in short-term outcomes between the groups. The overall mortality is higher for patients on antiplatelet agents than warfarin.