Validation of qualitative analytical methods

This article reviews the state of the art in validating qualitative analytical methods. After introducing the scope of these qualitative methods, their main characteristics and how they differ from quantitative analysis methods, we propose a classification according to the detection system. We discuss the institutions, programs and documents dealing with the validation of qualitative methods, and we present the performance parameters- false positive and negative, sensitivity and specificity rate, cut-off, unreliability region, ruggedness and cross-reactivity. We also briefly describe the various strategies used to validate qualitative analytical methods - Contingency Tables, Bayes' Theorem, Statistical Hypothesis Tests and Performance Characteristic Curves. (C) 2003 Published by Elsevier B.V.