Factors involved in validity measurements of diagnostic tests for approximal caries--a meta-analysis.

In this study, a meta-analysis was performed on published validity parameters of visual inspection, radiographic examination and visual inspection upon fibreoptic transillumination (FOTI) in approximal caries diagnosis. It was the objective to investigate the influence of the diagnostic test, the study design and the validation method on reported validity. Sensitivities and specificities reported in the literature were transformed into D2 values, representing the performance of a diagnostic method above chance, or of the observer using it, in a single parameter. Dz values were neither statistically significantly different between visual inspection, radiographic examination and FOTI nor between 'weak' and 'strong' validation methods (p > 0.05). Dz values obtained from in vivo studies were significantly different from those obtained from in vitro studies (p < 0.05), indicating that study design had a significant impact on the measurement of the validity of the evaluated test for approximal caries diagnosis.