title: Length of hospital stay for treatment of deep venous thrombosis and the incidence of recurrent thromboembolism.
abstract: BACKGROUND
  Current guidelines suggest that all patients with acute deep venous thrombosis should be treated with intravenous heparin for at least 5 days, overlapping with warfarin sodium for 4 to 5 days.
  
  
  METHODS
  Using linked state of California hospital discharge records from 1991 to 1994 we identified patients with acute deep venous thrombosis without pulmonary embolism, and determined the 6-month cumulative incidence of rehospitalization for recurrent thromboembolism. Coding was validated by reviewing the charts of 218 patients matched with the statewide data from 4 local hospitals.
  
  
  RESULTS
  A total of 36924 linked records met study criteria. In the validation group, objectively confirmed thrombosis that was treated with intravenous heparin followed by warfarin was noted in 20%, 65%, 94%, and 95% of the patients who were hospitalized for 2 or fewer days or 3, 4, or 5 or more days, respectively. Statewide, among patients hospitalized for 3, 4, 5, and 6 days, the 6-month cumulative incidence of hospitalization for recurrent thromboembolism was 5.4%, 5.1%, 5.4%, and 6.0%, respectively. Multivariate modeling of patients hospitalized for 3 to 10 days revealed that recurrent thromboembolism was associated with the length of hospitalization (odds ratio [OR], 1.06 each additional day; 95% confidence interval [CI], 1.04-1.08), presence of malignancy (OR, 1.58; 95% CI, 1.46-1.68), age (OR, 0.85 each 10 years; 95% CI, 0.84-0.86), dementia (OR, 0.38; 95% CI, 0.26-0.49), hospitalization for multiple injuries within 3 months (OR, 0.46; 95% CI, 0.32-0.60), and surgery within 3 months (OR, 0.84; 95% CI, 0.78-0.90).
  
  
  CONCLUSIONS
  We found no evidence that a stay of 4 days for treatment of deep venous thrombosis was associated with a higher rate of recurrent thromboembolism compared with hospitalization for 5 or more days. Although the evidence was not as strong, the incidence of recurrent thromboembolism after a stay of 3 days appeared comparable with that after a stay of 5 days. These findings suggest that fewer than 5 days of intravenous heparin overlapping with warfarin may provide effective initial treatment for deep venous thrombosis among patients deemed ready for hospital discharge.
authors.affiliation: Division of General Medicine, University of California at Davis, Sacramento 95817, USA. rhwhite@ucdavis.edu
authors.forename: R H
authors.initials: RH
authors.lastname: White
authors.forename: H
authors.initials: H
authors.lastname: Zhou
authors.forename: P S
authors.initials: PS
authors.lastname: Romano
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use; D005260:Female; D006801:Humans; D015994:Incidence; D007902:Length of Stay; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications; D012008:Recurrence; D013924:Thrombophlebitis / Q000188:drug therapy* / Q000209:etiology / Q000401:mortality; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin