title: Deep venous thrombosis and ABO blood group are unrelated in trauma patients.
abstract: BACKGROUND
  Although epidemiologic studies of the general population have demonstrated a deficit of blood group O among patients with deep venous thrombosis (DVT), few studies have evaluated the importance of blood group in high-risk patients. The purpose of this study was to evaluate the importance of ABO blood group as a thrombotic risk factor in injured patients.
  
  
  METHODS
  Injured patients with a discharge diagnosis of DVT were identified from an institutional trauma registry and compared with control patients matched for age and Injury Severity Score. ABO blood types of patients and controls were obtained from the regional blood center database.
  
  
  RESULTS
  Three hundred forty-three case-control pairs were identified from a total of 401 consecutive cases of DVT. Blunt injury was the predominant mechanism of injury, accounting for 90.4% of cases. Chest (p = 0.01) and extremity (p < 0.001) Abbreviated Injury Scale scores were independent predictors of DVT. However, there was no significant difference in blood group distribution or the A to O ratio between patients with and without DVT. For non-type O patients, the odds ratio for developing DVT was 1.1 (95% confidence interval, 0.8-1.5; p = 0.5) in comparison with type O patients.
  
  
  CONCLUSIONS
  These data do not support a clinically relevant association between blood type and DVT in trauma patients. Injury-associated derangements of coagulation may be more important than any hypercoagulability related to blood type in this population.
authors.affiliation: Division of Vascular Surgery, Harborview Medical Center, Seattle, Washington, USA.
authors.forename: Yvonne M
authors.initials: YM
authors.lastname: Carter
authors.forename: Michael T
authors.initials: MT
authors.lastname: Caps
authors.forename: Mark H
authors.initials: MH
authors.lastname: Meissner
mesh_terms: D000017:ABO Blood-Group System / Q000009:adverse effects* / Q000097:blood*; D015998:Abbreviated Injury Scale; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015601:Injury Severity Score; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012307:Risk Factors; D020246:Venous Thrombosis / Q000097:blood* / Q000209:etiology*; D014947:Wounds and Injuries / Q000097:blood* / Q000150:complications*
chemical_list: D000017:ABO Blood-Group System