title: Risk of venous thromboembolism in patients with liver disease: a nationwide population-based case-control study.
abstract: OBJECTIVE
  It is known that liver disease can cause an imbalance in the coagulation system, but available data on liver disease and risk of venous thromboembolism are conflicting. We examined the risk of venous thromboembolism in patients hospitalized with liver diseases.
  
  
  METHODS
  We conducted a nationwide Danish case-control study of incident cases of venous thromboembolism from 1980 to 2005 using population-based data from the National Registry of Patients, and from the Civil Registration System. We used conditional logistic regression to compute the relative risk of venous thromboembolism in patients with liver disease compared to population controls. We then excluded patients with known malignancy (diagnosed either before or up to 3 months after the venous thromboembolism) or fractures, trauma, surgery, or pregnancy within 90 days before the venous thromboembolism to estimate the risk associated with unprovoked venous thromboembolism.
  
  
  RESULTS
  A total of 99,444 patients with venous thromboembolism and 496,872 population controls were included in the study. Patients with liver disease had a clearly increased relative risk of venous thromboembolism, varying from 1.74 (95% CI, 1.54-1.95) for liver cirrhosis to 1.87 (95% CI, 1.73-2.03) for non-cirrhotic liver disease. The risks were higher for deep venous thrombosis compared with pulmonary embolism. In the analysis, restricted to 67,519 patients with unprovoked venous thromboembolism and 308,614 population controls, we found slightly higher relative risks: 2.06 (95% CI, 1.79-2.38) for liver cirrhosis and 2.10 (95% CI, 1.91-2.31) for non-cirrhotic liver disease.
  
  
  CONCLUSIONS
  Patients with liver disease have a substantially increased risk of venous thromboembolism.
authors.affiliation: Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Alle 43-45, Aarhus N, Denmark. kks@dce.au.dk
authors.forename: Kirstine Kobberøe
authors.initials: KK
authors.lastname: Søgaard
authors.forename: Erzsébet
authors.initials: E
authors.lastname: Horváth-Puhó
authors.forename: Henning
authors.initials: H
authors.lastname: Grønbaek
authors.forename: Peter
authors.initials: P
authors.lastname: Jepsen
authors.forename: Hendrik
authors.initials: H
authors.lastname: Vilstrup
authors.forename: Henrik Toft
authors.initials: HT
authors.lastname: Sørensen
mesh_terms: D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008107:Liver Diseases / Q000097:blood / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011655:Pulmonary Embolism / Q000209:etiology*; D012307:Risk Factors; D054556:Venous Thromboembolism / Q000209:etiology; D020246:Venous Thrombosis / Q000209:etiology*