Statistical methods for the estimation of sensitivity and specificity of site-specific diagnostic tests.

The performance of periodontal diagnostic tests is often evaluated by estimating their sensitivity and specificity with respect to a traditionally accepted standard test regarded as a "gold standard" in making the diagnosis. Correlated samples of binary data arise in dental research. The fundamental unit for analysis is occasionally the site rather than the patient in site-specific dental studies. Statistical methods that take into account the within-patient correlation should be employed to estimate the sensitivity and the specificity of diagnostic tests since site-specific results within a patient can be highly correlated. Several statistical methods are introduced for the estimation of the sensitivity and the specificity of site-specific diagnostic tests; these techniques are applied to the data from a study involving an enzymatic diagnostic test to motivate and illustrate the estimation of the sensitivity and the specificity of periodontal diagnostic tests.