How many myocardial infarctions should we rule out?

We used computer simulation to estimate the consequences of four admitting strategies (coronary care unit, intermediate care unit, routine ward care, or outpatient follow-up) on cost, outcome, admission threshold probabilities, and false-positive admission rates for patients with acute myocardial infarction. At virtually any probability of acute myocardial infarction, replacing more intensive by less intensive strategies saved money but increased mortality and decreased life expectancy. Therefore, choices among strategies may be made by using the most effective strategy for progressively lower and lower risk patients until the additional cost per additional life saved reaches a cutoff value; then, a less expensive strategy is selected. With sample cutoff values of $1 and $2 million per life saved, the marginal threshold admission probabilities were: (table; see text) These results imply that the acceptable proportion of false-positive admissions may be as high as 70% to 80%; lower rates could indicate excessively restrictive admitting policies. Clinicians may be operating closer to the optimal decision point than has previously been asserted.