Effects of uncertain results on sensitivity and specificity of diagnostic tests

Abstract

The sensitivity, specificity, and predictive values of a diagnostic test indicate its efficacy to rule in or out a diagnosis. Knowledge of these indices is necessary for cost-effective patient management and rational use of clinical tests.1 Traditional methods to estimate these values include true and false positive and negative results. The classic estimations of these diagnostic indexes are quite simple. The sensitivity of a diagnostic test is the likelihood of a positive result when the disease is present (the number of true positive subjects divided by the total number of diseased subjects).