Mild head injury, anticoagulants, and risk of intracranial injury.

We studied intracranial damage in patients with mild head injuries who were taking warfarin. Of the 215,785 individuals who visited the Mount Auburn and Beth Israel accident and emergency departments during our study, we identified records for 144 patients by anticoagulation status and computed tomography (CT) imaging. We retrospectively reviewed these patients and ten (7%, 95% CI 3-11) with clinically important injuries on cranial CT. Our findings suggest that patients with head injuries who receive anticoagulants have a similar or greater risk of intracranlal injury to those falling into a previously defined moderate-risk category, invalidating a previous conclusion that CT scanning is unnecessary in such patients.