Dalteparin vs. enoxaparin as prophylaxis for deep-vein thrombosis after total hip or knee arthroplasty: a retrospective analysis.

OBJECTIVE To assess the clinical and economic consequences of a formulary switch from enoxaparin to dalteparin as first-line prophylaxis for deep-vein thrombosis in patients undergoing inpatient rehabilitation after total hip arthroplasty or total knee arthroplasty. DESIGN Retrospective cohort study. RESULTS There were 461 patients eligible for the study. The age-adjusted risk of a deep-vein thrombosis event confirmed by duplex ultrasonography among patients treated with dalteparin was substantially lower than among patients treated with enoxaparin, whereas the age-adjusted risk of a bleeding event in the dalteparin group was also lower than that in the enoxaparin group. Adjusted per capita costs of deep-vein thrombosis prophylaxis during the rehabilitation stay were $129 lower among subjects treated with dalteparin. CONCLUSION The switch to dalteparin as a first-line therapy for deep-vein thrombosis prophylaxis in the rehabilitation period after total hip arthroplasty or total knee arthroplasty has led to substantial cost savings for Kessler Institute without compromising patient care.