It was also found that physicians don't prescribe warfarin for patients over the age of 80 who have atrial fibrillation, even though their risk of stroke is high. But the physicians attribute it to other causes. Dr. Brian F. Gage, from Washington University School of Medicine in St. Louis, and his associates created a National Registry of Atrial Fibrillation II data set. The study consisted of 16,007 non-Hispanic whites, 797 blacks, and 468 Hispanic subjects. Warfarin was prescribed for 49.7 % of whites, 43.2 % of blacks, and 40.2 % of Hispanics. Warfarin use was associated with a 35 % reduction in strokes than the 65% which as proposed during the clinical trials. The drug was even less effective in preventing stroke among minority patients.
Dr. Elaine M. Hylek at Boston University School of Medicine and her associates to determine the reasons why physicians don't prescribe warfarin for patients with atrial fibrillation followed 405 patients age 65 or older who were admitted to a hospital for atrial fibrillation. They found that 51 % of the patients were started on warfarin and found that the most common reasons that physicians cited for not prescribing warfarin were hemorrhage, falls, and patient refusal or history of nonadherence, mental impairment, alcohol abuse and advanced illness. Hence it is necessary for further research to find an alternative stroke prevention strategies that don't increase hemorrhagic risk at the same time prevent stokes effectively.