title: Analysis of venous thromboprophylaxis duration and outcomes in orthopedic patients.
abstract: BACKGROUND
  Venous thromboembolism (VTE) following total hip replacement (THR) and total knee replacement (TKR) surgery imposes significant health and economic burden.
  
  
  OBJECTIVE
  To examine the impact of thromboprophylaxis duration on deep vein thrombosis (DVT), pulmonary embolism (PE), total VTE (DVT and PE), and bleeding events among THR/TKR patients.
  
  
  METHODS
  A retrospective study (April 1, 2004, to December 31, 2006) was conducted using a US health plan claims database linked to an inpatient database containing medication use. Outcomes were compared using χ2 tests; predictors of outcomes were analyzed using multivariate logistic regression.
  
  
  RESULTS
  Of 3497 patients, 3195 (91%) received thromboprophylaxis for =1 day postsurgery. Most patients (67%) received short-duration (1-14 days) rather than extended-duration (>14 days) thromboprophylaxis. The incidence of thromboembolic and bleeding events was higher in those who received short-duration thromboprophylaxis: DVT (2.84% vs 1.24%; P = .0038), PE (1.12% vs 0.19%; P = .0052), total VTE (3.96% vs 1.43%; P <.0001), and major bleeding (1.68% vs 0.38%; P = .0011). Multivariate logistic regressions (adjusted for observed demographic and clinical characteristics) revealed similar results. Baseline comorbidity score was significantly associated with major bleeding; most of the bleeding events in those who received short-duration thromboprophylaxis occurred within the first 14 days.
  
  
  CONCLUSIONS
  In this database analysis of patients who had undergone THR/TKR surgery, a large proportion of patients did not receive the minimum duration of thromboprophylaxis recommended by the guidelines. Extended-duration thromboprophylaxis was associated with a significantly lower risk of DVT, PE, and VTE compared with short-duration thromboprophylaxis.
authors.affiliation: Division of Hematology and Clinical Epidemiology, Ottawa Hospital Research Institute, Canada.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Wells
authors.forename: Bijan J
authors.initials: BJ
authors.lastname: Borah
authors.forename: Nishan
authors.initials: N
authors.lastname: Sengupta
authors.forename: Dylan
authors.initials: D
authors.lastname: Supina
authors.forename: Heather P
authors.initials: HP
authors.lastname: McDonald
authors.forename: Louis M
authors.initials: LM
authors.lastname: Kwong
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D019644:Arthroplasty, Replacement, Hip / Q000379:methods*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D006801:Humans; D007345:Insurance Claim Review; D015999:Multivariate Analysis; D009985:Orthopedics; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use; D011655:Pulmonary Embolism / Q000517:prevention & control; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D016896:Treatment Outcome; D054556:Venous Thromboembolism / Q000517:prevention & control*; D020246:Venous Thrombosis / Q000517:prevention & control
chemical_list: D000925:Anticoagulants; D010975:Platelet Aggregation Inhibitors