title: Benefits and risks of anticoagulation resumption following traumatic brain injury.
abstract: OBJECTIVE
  The increased risk of hemorrhage associated with anticoagulant therapy following traumatic brain injury creates a serious dilemma for medical management of older patients: Should anticoagulant therapy be resumed after traumatic brain injury, and if so, when?
  
  
  OBJECTIVE
  To estimate the risk of thrombotic and hemorrhagic events associated with warfarin therapy resumption following traumatic brain injury.
  
  
  METHODS
  Retrospective analysis of administrative claims data for Medicare beneficiaries aged at least 65 years hospitalized for traumatic brain injury during 2006 through 2009 who received warfarin in the month prior to injury (n = 10,782).
  
  
  METHODS
  Warfarin use in each 30-day period following discharge after hospitalization for traumatic brain injury.
  
  
  METHODS
  The primary outcomes were hemorrhagic and thrombotic events following discharge after hospitalization for traumatic brain injury. Hemorrhagic events were defined on inpatient claims using International Classification of Diseases, Ninth Revision, Clinical Modification codes and included hemorrhagic stroke, upper gastrointestinal bleeding, adrenal hemorrhage, and other hemorrhage. Thrombotic events included ischemic stroke, pulmonary embolism, deep venous thrombosis, and myocardial infarction. A composite of hemorrhagic or ischemic stroke was a secondary outcome.
  
  
  RESULTS
  Medicare beneficiaries with traumatic brain injury were predominantly female (64%) and white (92%), with a mean (SD) age of 81.3 (7.3) years, and 82% had atrial fibrillation. Over the 12 months following hospital discharge, 55% received warfarin during 1 or more 30-day periods. We examined the lagged effect of warfarin use on outcomes in the following period. Warfarin use in the prior period was associated with decreased risk of thrombotic events (relative risk [RR], 0.77 [95% CI, 0.67-0.88]) and increased risk of hemorrhagic events (RR, 1.51 [95% CI, 1.29-1.78]). Warfarin use in the prior period was associated with decreased risk of hemorrhagic or ischemic stroke (RR, 0.83 [95% CI, 0.72-0.96]).
  
  
  CONCLUSIONS
  Results from this study suggest that despite increased risk of hemorrhage, there is a net benefit for most patients receiving anticoagulation therapy, in terms of a reduction in risk of stroke, from warfarin therapy resumption following discharge after hospitalization for traumatic brain injury.
authors.affiliation: Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, Baltimore.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Albrecht
authors.affiliation: Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, Baltimore.
authors.forename: Xinggang
authors.initials: X
authors.lastname: Liu
authors.affiliation: Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: Mona
authors.initials: M
authors.lastname: Baumgarten
authors.affiliation: Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore.
authors.forename: Patricia
authors.initials: P
authors.lastname: Langenberg
authors.affiliation: Division of Pharmacy Practice, Fairleigh Dickinson University School of Pharmacy, Florham Park, New Jersey.
authors.forename: Gail B
authors.initials: GB
authors.lastname: Rattinger
authors.affiliation: Shock, Trauma and Anesthesiology Research (STAR)-Organized Research Center, National Study Center for Trauma and Emergency Medical Services, University of Maryland, Baltimore.
authors.forename: Gordon S
authors.initials: GS
authors.lastname: Smith
authors.affiliation: Department of Medicine, University of Maryland School of Medicine, Baltimore.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Gambert
authors.affiliation: Department of Medicine, University of Maryland School of Medicine, Baltimore.
authors.forename: Stephen S
authors.initials: SS
authors.lastname: Gottlieb
authors.affiliation: Department of Pharmaceutical Health Services Research, University of Maryland School of Pharmacy, Baltimore2Department of Epidemiology and Public Health, University of Maryland School of Medicine, Baltimore6IMPAQ International LLC, Columbia, Maryland.
authors.forename: Ilene H
authors.initials: IH
authors.lastname: Zuckerman
mesh_terms: D000307:Adrenal Gland Diseases / Q000139:chemically induced; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D001281:Atrial Fibrillation / Q000150:complications / Q000188:drug therapy*; D001930:Brain Injuries / Q000150:complications*; D002545:Brain Ischemia / Q000209:etiology / Q000517:prevention & control; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced; D006470:Hemorrhage / Q000139:chemically induced*; D006801:Humans; D020300:Intracranial Hemorrhages / Q000139:chemically induced; D008297:Male; D009203:Myocardial Infarction / Q000209:etiology / Q000517:prevention & control; D011655:Pulmonary Embolism / Q000209:etiology / Q000517:prevention & control; D012189:Retrospective Studies; D018570:Risk Assessment; D020521:Stroke / Q000209:etiology / Q000517:prevention & control; D013927:Thrombosis / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000209:etiology / Q000517:prevention & control; D014859:Warfarin / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin