The value of a diagnostic test is dependent not only on the specificity and sensitivity of the test, but also on the pre-test probability of the test. Given these three values, we can calculate the probability that a patient has the disease if the results of the test are negative or positive. Although these calculations can be tedious, the calculator shown below can perform them for you.
Just click on the gender, age group, and type of symptoms (No chest pain, non-anginal chest pain, atypical anginal chest pain, and typical anginal chest pain). The calculator will show you the probability of significant coronary artery disease given the symptoms, age and gender, and also the probability if you were to perform one of the listed diagnostic tests and the results were positive or negative. Also calculated is the accuracy, which is the probability that the conclusion of the test is correct.
The data for the pre-test probabilities is based on catheterization data summarized in Diamond & Forrester (NEJM 1979;300(24):1350-1358 and J Clin Invest 1980;65(5):1210-1221), while the sensitivity and specificity for exercise ECG is based on a meta-analysis by Gianrossi et al. (Circulation 1989;80(1):87-98). The sensitivity and specificity of exercise echo and nuclear studies is based on data from Fleischmann et al. (JAMA 1998;280(10):913), and the data for sensitivity and specificity of dobutamine, dipyridamole, and adenosine echocardiography and nuclear testing is based on a meta-analysis by the Kim et al. (Am Heart J 2001;142(6):934-44). The dipyradomole and adenosine data was averaged for each modality. The sensitivity and specificity of exercise ECG, treadmill echocardiography and treadmill nuclear studies in women is based on a meta-analysis by Kwok et al. (Am J Cardiol. 1999 Mar 1;83(5):660-6). The sensitivities and specificities for pharmacological stress testing are not adjusted for women because there was no evidence for a significant difference in the limited data available in Kim.
Date created: June 19, 2000 Last modified: May 24, 2019 Copyright © 2000, 2001, 2002, 2003, 2019 David T. Linker, M.D. Maintained by: David T. Linker, M.D. David T. Linker, M.D.