LENGTH OF HOSPITAL STAY FOR TREATMENT OF DEEP VENOUS THROMBOSIS AND THE INCIDENCE OF RECURRENT THROMBOEMBOLISM

Background: Current guidelines suggest that all patients with acute de ep venous thrombosis should be treated with intravenous heparin for at least 5 days, overlapping with warfarin sodium for 4 to 5 days. Metho ds: Using linked state of California hospital discharge records from 1 991 to 1994 we identified patients with acute deep venous thrombosis w ithout pulmonary embolism, and determined the 6-month cumulative incid ence of rehospitalization for recurrent thromboembolism. Coding was va lidated by reviewing the charts of 218 patients matched with the state wide data from 4 local hospitals. Results: A total of 36 924 linked re cords met study criteria. In the validation group, objectively confirm ed thrombosis that was treated with intravenous heparin followed by wa rfarin was noted in 20%, 65%, 94%, and 95% of the patients who were ho spitalized for 2 or fewer days or 3, 4, or 5 or more days, respectivel y. Statewide, among patients hospitalized for 3, 4, 5, and 6 days, the 6-month cumulative incidence of hospitalization for recurrent thrombo embolism was 5.4%, 5.1%, 5.4%, and 6.0%, respectively. Multivariate mo deling of patients hospitalized for 3 to 10 days revealed that recurre nt 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), a ge (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 month s (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 inci dence of recurrent thromboembolism after a stay of 3 days appeared com parable 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.