A DECISION-ANALYSIS OF STREPTOKINASE PLUS HEPARIN AS COMPARED WITH HEPARIN ALONE FOR DEEP-VEIN THROMBOSIS

It is uncertain whether patients with proximal deep-vein thrombosis sh ould be treated with streptokinase followed by intravenous heparin or with intravenous heparin alone. Published reports indicate that strept okinase plus heparin increases the risk of bleeding, including central nervous system bleeding and death, but decreases the risk of postphle bitic syndrome. Previous recommendations regarding these treatments ha ve not considered patients' preferences or the values they attach to t he possible outcomes of therapy. Methods. We used decision analysis to combine published estimates of the probabilities of various adverse o utcomes of treatment (bleeding, pulmonary embolism, postphlebitic synd rome, and death) with the values patients placed on these outcomes. We questioned 36 patients about the values they attached to each outcome . Sixteen patients had had deep-vein thrombosis, and 20 had not. Resul ts. By the values they attached to the outcomes, all 36 patients indic ated that they were unwilling to accept an increased risk of death to avoid postphlebitic syndrome. According to the decision analysis, hepa rin alone was the better treatment for all 36 patients. As compared wi th streptokinase plus heparin, heparin alone provided 29 days of addit ional life expectancy over the predicted life expectancy of 20 years. Although the difference between the two treatments was small, heparin alone remained the better treatment in sensitivity analyses that exami ned the reasonable ranges of probabilities of the clinical outcomes. C onclusions. The values patients placed on the outcomes of treatment fo r deep-vein thrombosis support the use of heparin alone over the combi ned use of streptokinase and heparin.