title: Mortality among head trauma patients taking preinjury antithrombotic agents: a retrospective cohort analysis from a Level 1 trauma centre.
abstract: Bleeding represents the most well-known and the most feared complications caused by the use of antithrombotic agents. There is, however, limited documentation whether pre-injury use of antithrombotic agents affects outcome after head trauma. The aim of this study was to define the relationship between the use of preinjury antithrombotic agents and mortality among elderly people sustaining blunt head trauma.
  
  
  
  A retrospective cohort analysis was performed on the hospital based trauma registry at Oslo University Hospital. Patients aged 55 years or older sustaining blunt head trauma between 2004 and 2006 were included. Multivariable logistic regression analyses were used to identify independent predictors of 30-day mortality. Separate analyses were performed for warfarin use and platelet inhibitor use.
  
  
  
  Of the 418 patients admitted with a diagnosis of head trauma, 137 (32.8 %) used pre-injury antithrombotic agents (53 warfarin, 80 platelet inhibitors, and 4 both). Seventy patients died (16.7 %); 15 (28.3 %) of the warfarin users, 12 (15.0 %) of the platelet inhibitor users, and two (50 %) with combined use of warfarin and platelet inhibitors, compared to 41 (14.6 %) of the non-users. There was a significant interaction effect between warfarin use and the Triage Revised Trauma Score collected upon the patients' arrival at the hospital. After adjusting for potential confounders, warfarin use was associated with increased 30-day mortality among patients with normal physiology (adjusted OR 8,3; 95 % CI, 2.0 to 34.8) on admission, but not among patients with physiological derangement on admission. Use of platelet inhibitors was not associated with increased mortality.
  
  
  
  The use of warfarin before trauma was associated with increased 30-day mortality among a subset of patients. Use of platelet inhibitors before trauma was not associated with increased mortality. These results indicate that patients on preinjury warfarin may need closer monitoring and follow up after trauma despite normal physiology on admission to the emergency department.
authors.affiliation: Centre for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85 Vinderen, N-0319, Oslo, Norway. sigrid.narum@diakonsyk.no.|Department of Pharmacology, Oslo University Hospital, Oslo, Norway. sigrid.narum@diakonsyk.no.
authors.forename: Sigrid
authors.identifier: 0000-0002-7610-5322
authors.initials: S
authors.lastname: Narum
authors.affiliation: Department of Pharmacology, University of Oslo, Oslo, Norway.
authors.forename: Odd
authors.initials: O
authors.lastname: Brørs
authors.affiliation: Former Intensive Care Unit, Oslo University Hospital, Oslo, Norway.
authors.forename: Olav
authors.initials: O
authors.lastname: Stokland
authors.affiliation: Centre for Psychopharmacology, Diakonhjemmet Hospital, PO Box 85 Vinderen, N-0319, Oslo, Norway.|Department of Pharmacology, Oslo University Hospital, Oslo, Norway.
authors.forename: Marianne K
authors.initials: MK
authors.lastname: Kringen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D006259:Craniocerebral Trauma / Q000401:mortality*; D004359:Drug Therapy, Combination; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D005343:Fibrinolytic Agents / Q000009:adverse effects*; D006801:Humans; D015601:Injury Severity Score; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D010975:Platelet Aggregation Inhibitors / Q000009:adverse effects; D012189:Retrospective Studies; D014193:Trauma Centers; D014859:Warfarin / Q000009:adverse effects
chemical_list: D005343:Fibrinolytic Agents; D010975:Platelet Aggregation Inhibitors; D014859:Warfarin
keywords: Antithrombotic agents; Blunt head trauma; Mortality; Older adults; Platelet inhibitors; Warfarin