Medical Decision-Making Applied to the Diagnosis of Coronary Artery Disease

The management of coronary artery disease (CAD) represents an excellent field for the application of methods of medical decision-making. The diagnosis of CAD is generally based on 3 sources of information, i.e. 1) pre-test or prior probability of disease derived from patients’s characteristics such as age, sex, nature of complaints and presence of risk factors, 2) results of non-invasive tests such as exercise electrocardiography and myocardial perfusion imaging, and 3) coronary arteriography which is the usually accepted reference method. The choice of a diagnostic strategy is determined by the information content of the non-invasive tests which depends on the pre-test likelihood of CAD and on the test characteristics (sensitivity and specificity). Other factors, however, play a role in the decision-making process. Firstly, beyond the mere presence or absence of CAD, the estimation of its severity (0, 1, 2 or 3 vessel-disease) can influence the choice of diagnostic tests and of therapeutic modalities. Secondly, among physicians, the opinions regarding the medical cost/benefit effectiveness of various diagnostic and therapeutic procedures may vary. Thirdly, the economic cost and the available financial resources to obtain a reduction of diagnostic uncertainty could be taken into account.