The application of decision theory to the prevention of deep vein thrombosis following myocardial infarction.

Death from pulmonary embolism secondary to deep vein thrombosis following myocardial infarction can be prevented by prophylactic heparin therapy but this itself may result in death from a bleeding complication. The frequency of thromboembolism complicating myocardial infarction varies with the age and other factors and the frequency of complications of heparin therapy also varies with age. The prior probabilities have been obtained from an investigation to select, on the basis of decision theory, those patients who should be treated with prophylactic heparin therapy in order to reduce to a minimum the total mortality from both thromboembolism and heparin bleeding. The result of a study applying these principles is described.