Testing stable angina. Expert opinion versus decision analysis.

Controversy still surrounds the use of invasive and noninvasive tests after establishing the clinical diagnosis of stable angina pectoris. The authors employed threshold analysis, a multifactorial mathematical instrument, and the risk and benefit data available in 1983 to determine that the optimal diagnostic approach is to perform a stress test first and then consider angiographic evaluation and surgery for those patients with a positive result. This decision rule was compared with the diagnostic approaches proposed by 61 randomly selected board-certified cardiologists. Fifteen different two-test strategies were proposed by the 61 experts. Fifty-three chose a stress test as the initial procedure and 37 would proceed to coronary angiography if the stress test were positive. Thus a majority of the experts studied (60.6%) proposed an approach identical to the result of threshold analysis. Three respondents thought that no tests were necessary for the evaluation of stable angina pectoris. Twelve cardiologists would not recommend coronary angiography in stable angina patients with unequivocally positive stress tests. Their degree of familiarity and practical experience with the invasive procedure, as well as their perception of risks and benefits of coronary angiography and coronary artery bypass surgery, was not different than that of the cardiologists holding the majority view. For this group the decision analytic model could be used to correct judgmental biases and to optimize the diagnostic evaluation of coronary artery disease.