P. Nourjah, R. A. Bonnel, A. D. Brinker, M. I. Avigan, CDER, FDA, Rockville, MD
Background: Warfarin, a commonly used anticoagulant, is associated with a significant risk for bleeding, approaching 5% in some studies.We conducted an analysis of National Hospital Ambulatory Care Survey (NHMACS) to characterize patients who were admitted to emergency departments (EDs) with a diagnosis of bleeding while receiving warfarin therapy.
Methods: Publicly available NHMACS data for calendar years 1999 to 2003 were obtained from the NCHS website. International Classification of Diseases, 9th Revision, Clinical Modification (ICD -9CM) codes for bleeding (430-432, 455-578, 599.7, 623.8, 626.2, 784.7, 786.3, 459, 719.1-719.2 and 423) as well as internal NHAMCS codes were used to identify the cases related to warfarin. Results were projected to the national level.
Results: Each year on average, 112,179 visits were made to EDs by patients who had bleeding associated with warfarin. 56% of visits were by females; the median age was 72 years. 47% of visits resulted in hospitalization and an additional 2% resulted in admission for 23-hour observation. 13% of the hospital admissions were to intensive care units.
A small fraction (0.2%) of the cases were dead on arrival to the ED or associated with death while being treated in the ED. 84% of all visits were associated with a diagnosis consistent with gastrointestinal (GI) bleeding.
Conclusions: Complications of warfarin treatment continue to be linked to significant morbidity and mortality. The most common complication associated with warfarin use in this study was GI bleeding.