A decision analysis of streptokinase plus heparin as compared with heparin alone for deep-vein thrombosis.
BACKGROUND
It is uncertain whether patients with proximal deep-vein thrombosis should be treated with streptokinase followed by intravenous heparin or with intravenous heparin alone. Published reports indicate that streptokinase plus heparin increases the risk of bleeding, including central nervous system bleeding and death, but decreases the risk of postphlebitic syndrome. Previous recommendations regarding these treatments have not considered patients' preferences or the values they attach to the possible outcomes of therapy.


METHODS
We used decision analysis to combine published estimates of the probabilities of various adverse outcomes of treatment (bleeding, pulmonary embolism, postphlebitic syndrome, 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.


RESULTS
By the values they attached to the outcomes, all 36 patients indicated that they were unwilling to accept an increased risk of death to avoid postphlebitic syndrome. According to the decision analysis, heparin alone was the better treatment for all 36 patients. As compared with streptokinase plus heparin, heparin alone provided 29 days of additional 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 examined the reasonable ranges of probabilities of the clinical outcomes.


CONCLUSIONS
The values patients placed on the outcomes of treatment for deep-vein thrombosis support the use of heparin alone over the combined use of streptokinase and heparin.
O'Meara
J J
JJ
Division of General Medicine, University of North Carolina at Chapel Hill 27599-7110.
McNutt
R A
RA
Evans
A T
AT
Moore
S W
SW
Downs
S M
SM
D002543:Cerebral Hemorrhage / Q000139:chemically induced; D003661:Decision Support Techniques; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D006801:Humans; D008875:Middle Aged; D010358:Patient Participation / Q000706:statistics & numerical data; D011186:Postphlebitic Syndrome / Q000139:chemically induced; D011336:Probability; D011655:Pulmonary Embolism / Q000139:chemically induced; D016032:Randomized Controlled Trials as Topic; D012306:Risk; D012680:Sensitivity and Specificity; D013300:Streptokinase / Q000008:administration & dosage / Q000009:adverse effects* / Q000627:therapeutic use; D015912:Thrombolytic Therapy / Q000009:adverse effects*; D013924:Thrombophlebitis / Q000188:drug therapy*; D016896:Treatment Outcome
D006493:Heparin; D013300:Streptokinase