Use of low molecular weight heparin (dalteparin), once daily, for the treatment of deep vein thrombosis - A feasibility and health economic study in an outpatient setting

Objectives. To test the safety and feasibility of treating deep vein thrombosis (DVT) in an outpatient setting, using the low molecular weight heparin dalteparin, to calculate the potential and actual cost reductions achievable as a result of such a treatment regimen. Design. An open, nonrandomized, multicentre trial. Setting. Fourteen hospitals in central Sweden. Subjects. Ambulant patients, aged 18 years or older, with symptomatic DVT in the leg, diagnosed using phlebography or ultrasound (Duplex-Doppler). Interventions. Dalteparin (Fragmin(R)) at a fixed dose of 200 IU kg(-1) body weight, was administered once daily subcutaneously for at least 4 consecutive days. Treatment with warfarin was initiated from the first day of dalteparin administration. Outpatient treatment was encouraged whenever possible. Financial calculations were performed independently at two hospitals, giving an average cost for all actions. Outcome measures. Increasing severity of symptoms (or thromboembolic recurrences during the 3-month follow-up period), pulmonary embolism (PE), bleeding events, and death during the initial phase and follow-up period. Results. Of 434 patients, 35% and 64% were treated in hospital within 24 and 72 h, respectively, and thereafter as outpatients. The overall frequency of serious complications was 0.92% (exact 95% confidence interval, 0.25-2.35%) during the initial phase and one patient suffered a PE and three patients had a recurrent DVT during the follow-up period. A cost reduction of 2 705 529 Swedish crowns (34.5%) was achieved in this study compared with traditional in-patient treatment. Conclusions. Dalteparin, administered subcutaneously, once daily, for the initial treatment of DVT yields large cost reductions and is well tolerated and effective in an outpatient setting.