Whither the rationale for thrombolytic agent administration? A retrospective review of traditional intuitive decision-making using a decision analysis model.
Of 50 consecutive patients admitted to Nenagh Hospital coronary care unit 50 per cent did not develop a myocardial infarction. Only 10 patients had definite evidence of infarction on admission. Of the 40 remaining patients, only 15 subsequently developed electrocardiographic and enzymatic confirmation of infarction. Streptokinase was administered to 5 patients who did not infarct, and was not given to 10 patients who did. These decisions to use or withhold thrombolytic therapy were retrospectively reviewed using a computer programme incorporating a decision analysis of the benefits and risks of thrombolysis. The programme examined four scenarios that used different estimates of the chance of death from infarction (pdiMI), and different safety profiles of thrombolytics. The scenario that assumed the worst safety profile and estimated pdiMI from patient age would have recommended thrombolytic treatment to the most with, and to the least without, acute infarction (i.e. 60 per cent of patients with an infarct and 8 per cent without an infarct would have been treated). Depending on the scenario assumed, the traditional intuitive method of decision-making gained from 0.08 and 0.25 quality adjusted life years (QALY's) for the average patient. Had decision analysis been used to guide these decisions these gains would have been enhanced by from 0.21 to 0.28 QALY's per patient, regardless of scenario used.