Measuring the effectiveness of diagnostic markers in the presence of measurement error through the use of ROC curves

The area under the receiver operating characteristic curve is frequently used to assess the effectiveness of diagnostic markers in distinguishing between diseased and healthy individuals. These markers are generally subject to measurement error. In this paper confidence intervals for the area under the curve are developed which take measurement error into account. These intervals depend on the availability of replicated observations for the subject. Both equal and unequal numbers of replicates per subject are considered. The practice of averaging over replicates and then ignoring measurement error is examined and found wanting. Copyright (C) 2000 John Wiley and Sons, Ltd.