title: Incidence of thrombocytopenia in hospitalized patients with venous thromboembolism.
abstract: OBJECTIVE
  To determine the incidence of heparin-associated thrombocytopenia in patients receiving prophylaxis or treatment for venous thromboembolism.
  
  
  METHODS
  We assessed the database of the National Hospital Discharge Survey from 1979 through 2005 and complemented this with a meta-analysis of published literature.
  
  
  RESULTS
  Among 10,554,000 patients discharged from short-stay hospitals throughout the US with venous thromboembolism during the 27 years of study, secondary thrombocytopenia was coded in 38,000 patients (0.36%). From 1979 through 1992, secondary thrombocytopenia was coded in only 0.15% of hospitalized patients with venous thromboembolism. The frequency increased sharply to 0.54% from 1993 through 2005. Secondary thrombocytopenia was rarely diagnosed among 1,446,000 patients aged <40 years and among 77,000 women who had venous thromboembolism with deliveries. Meta-analysis of published literature showed a higher incidence among patients who received unfractionated heparin (UFH) for prophylaxis than those who received low-molecular-weight heparin (LMWH) for prophylaxis. Treatment resulted in smaller differences of the incidence between UFH and LMWH.
  
  
  CONCLUSIONS
  Heparin-associated thrombocytopenia is rare among patients aged <40 years and women following delivery. The risk of heparin-associated thrombocytopenia is more duration-related than dose-related, and higher with UFH when used for an extended duration. Our findings and those of the literature suggest that although heparin-associated thrombocytopenia is uncommon, the incidence can be minimized by use of LMWH, particularly if extended prophylaxis or extended treatment is required.
authors.affiliation: Research and Advanced Studies Program, Michigan State University, College of Osteopathic Medicine, Detroit Medical Center Campus, Detroit, MI, USA. steinp@trinity-health.org
authors.forename: Paul D
authors.initials: PD
authors.lastname: Stein
authors.forename: Russell D
authors.initials: RD
authors.lastname: Hull
authors.forename: Fadi
authors.initials: F
authors.lastname: Matta
authors.forename: Abdo Y
authors.initials: AY
authors.lastname: Yaekoub
authors.forename: Jane
authors.initials: J
authors.lastname: Liang
mesh_terms: D000328:Adult; D017677:Age Distribution; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006495:Heparin, Low-Molecular-Weight / Q000008:administration & dosage / Q000009:adverse effects*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011379:Prognosis; D018570:Risk Assessment; D017678:Sex Distribution; D013921:Thrombocytopenia / Q000139:chemically induced* / Q000453:epidemiology* / Q000503:physiopathology; D014481:United States / Q000453:epidemiology; D054556:Venous Thromboembolism / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight