title: Effect of preinjury warfarin use on outcomes after head trauma in Medicare beneficiaries.
abstract: BACKGROUND
  Elderly Americans are at increased risk of head trauma, particularly fall related. The effect of warfarin on head trauma outcomes remains controversial.
  
  
  METHODS
  Medicare beneficiaries with head injuries from 2009 to 2011 were identified by International Classification of Diseases (ICD)-9 code. Preinjury warfarin use was determined using Part D claims. Multiple logistic regression models determined the association of preinjury warfarin on need for hospitalization, intensive care unit care, and occurrence of intracranial hemorrhage. Association between warfarin and in-hospital mortality was assessed using a Cox proportional hazard model.
  
  
  RESULTS
  Of 11,078 head injured patients, 5.2% were injured while on warfarin. Preinjury warfarin increased the odds of intracranial hemorrhage by 40% and doubled the risk of 30-day in-hospital mortality after adjusting for demographic and clinical factors.
  
  
  CONCLUSIONS
  Warfarin at the time of head injury increases the risk of adverse outcomes in Medicare beneficiaries with head injuries. Caution should be used when initiating anticoagulation in elderly Americans at risk for trauma.
authors.affiliation: Department of Surgery, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Courtney E
authors.initials: CE
authors.lastname: Collins
authors.affiliation: Department of Surgery, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Elan R
authors.initials: ER
authors.lastname: Witkowski
authors.affiliation: Department of Surgery, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Flahive
authors.affiliation: Department of Surgery, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Fred A
authors.initials: FA
authors.lastname: Anderson
authors.affiliation: Department of Surgery, University of Massachusetts Medical School, Worcester, MA, USA. Electronic address: Heena.Santry@umassmemorial.org.
authors.forename: Heena P
authors.initials: HP
authors.lastname: Santry
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects; D006259:Craniocerebral Trauma / Q000150:complications / Q000191:economics / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007297:Inpatients; D007342:Insurance Benefits / Q000191:economics; D007362:Intensive Care Units; D020300:Intracranial Hemorrhages / Q000191:economics / Q000453:epidemiology* / Q000209:etiology; D008297:Male; D006278:Medicare; D011379:Prognosis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015996:Survival Rate; D013923:Thromboembolism / Q000150:complications / Q000517:prevention & control; D014481:United States / Q000453:epidemiology; D014859:Warfarin / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: Coumadin; Elderly; Head injury; Intracranial hemorrhage; Trauma; Warfarin