The effect of verification bias in the Naive estimators of accuracy of a binary diagnostic test

The assessment of a binary diagnostic test requires a knowledge of the disease status of all the patients in the sample through the application of a gold standard. In practice, the gold standard is not always applied to all of the patients, which leads to the problem of partial verification of the disease. When the accuracy of the diagnostic test is assessed using only those patients whose disease status has been verified using the gold standard, the estimators obtained in this way, known as Naive estimators, may be biased. In this study, we obtain the explicit expressions of the bias of the Naive estimators of sensitivity and specificity of a binary diagnostic test. We also carry out simulation experiments in order to study the effect of the veri. cation probabilities on the Naive estimators of sensitivity and specificity.