Dr. Lesly A. Dossett of Vanderbilt University Medical Center in Nashville and colleagues studied data from more than 1.2 million patients admitted to eligible trauma centers from 2002 to 2007, of which 36,270 patients were prescribed warfarin and 26,841 patients were age 65 and older.
The total proportion of warfarin users increased from 2.3 percent in 2002 to 4 percent in 2006, and in those age 65 and older, the proportion went from 7.3 percent in 2002 to 12.8 percent in 2006.
The study, published online ahead of print in the May issue of the journal Archives of Surgery, finds that overall, warfarin users were also more likely to die from their injuries compared to non-users -- 9.3 percent vs. 4.8 percent.
"The most profound impact is among younger patients with head injuries. While older patients with severe head injuries have high mortality rates whether or not they are warfarin users, warfarin use increases the mortality from severe head injuries by 50 percent in patients younger than 65 years," the study authors say. "These data support other reports that suggest that patients who undergo pre-injury anti-coagulation with warfarin are at increased risk of death after trauma."