A Computer-Derived Protocol to Aid in the Diagnosis of Emergency Room Patients with Acute Chest Pain

To determine whether data available to physicians in the emergency room can accurately identify which patients with acute chest pain are having myocardial infarctions, we analyzed 482 patients at one hospital. Using recursive partitioning analysis, we constructed a decision protocol in the format of a simple flow chart to identify infarction on the basis of nine clinical factors. In prospective testing on 468 other patients at a second hospital, the protocol performed as well as the physicians. Moreover, an integration of the protocol with the physicians' judgments resulted in a classification system that preserved sensitivity for detecting infarctions, significantly improved the specificity (from 67 per cent to 77 per cent, P<0.01) and positive predictive value (from 34 per cent to 42 per cent, P = 0.016) of admission to an intensive-care area. The protocol identified a subgroup of 107 patients among whom only 5 per cent had infarctions and for whom admission to non-intensive-care areas might be appropriate. This decision protocol warrants further wide-scale prospective testing but is not ready for routine clinical use. (N Engl J Med. 1982; 307:588–96.) CHEST pain is part of the symptom complex of about two thirds of patients admitted to a hospital with acute myocardial infarctions,¹ but the identification of patients whose chest pain represents acute myocardial infarction is among the most difficult problems in clinical medicine. Because of fear of the consequences of missing patients at high risk, emergency room physicians are encouraged to admit patients to “rule out myocardial infarction” if the diagnosis is uncertain. Although this practice increases the number of admissions of patients who do have acute myocardial infarction, it has led to a situation in which as few as.