SPECIFICITY OF ELECTROCARDIOGRAPHIC STRESS TEST IN WOMEN VERSUS MEN

Women are generally believed to be more apt to have false-positive electrocardiographic stress tests than men. Confusion exists, however, on whether the relatively high rate of false-positive results in women is a consequence of a low test specificity in this group, or a low positive predictive value of this test in a group with a relatively low prevalence of coronary disease. Several studies that purport to demonstrate low specificity of such testing in women1-4 are subject to "referral" or "workup" bias (i.e., stress tests were not excluded before definitive study), thus allowing these tests to influence selection for final confirmation of the diagnosis. It is well known that this type of bias results in falsely low specificity values for any test.5,6 Therefore, since the ECG stress test is currently used widely and often contributes to the selection of which patients will undergo coronary arteriography, confirmation of the diagnosis through arteriography will necessarily result in falsely low specificity values for stress testing. On the other hand, thallium-201 strep tests with [GRAPHICS] tomographic enhancement (single-photon emission computed tomography [SPECT]) are found to be highly accurate for detecting and quantitating coronary ischemia,7 can be applied to populations in which referral bias is absent, and therefore, can provide an alternative means to study and compare the characteristics of the electrocardiographic stress test in both sexes.