Contrast-enhanced multi-detector row spiral computed tomography (MDCT) has been introduced as a method for non-invasive visualization of coronary artery stenosis. To determine the diagnostic accuracy of MDCT coronary angiography, as compared to the “gold standard” invasive coronary angiography, sensitivity and specificity are estimated (95% Confidence Intervals). Three separate levels of estimation are computed: at the patient level, at the coronary artery level, and at the coronary artery segment level. We review the methodology for the estimation of sensitivity and specificity of non-clustered binary data (patient level analysis) and present a methodology for the estimation of sensitivity and specificity that considers the patient as a cluster and the coronary arteries (or coronary artery segments) as the diagnostic units of the study (DUOS) within each cluster. We also present how to estimate the weighted kappa for the comparison of ordinal measures of stenosis when non-clustered and clustered data are considered and the mean difference for the comparison of continuous measures of stenosis when non-clustered and clustered data are considered. Finally, we present a methods for determining the statistical precision of estimates sensitivity and specificity, weighted kappa and mean difference when clustered data are considered.
McCarthy, William F.; Thompson, Douglas R.; and Barton, Bruce A., "Coronary Evaluation Using Multi-detector Spiral Computed Tomography Angiography: Statistical Design and Analysis" (May 2007). COBRA Preprint Series. Working Paper 22.