The construction and use of diagnostic standards for radiographic caries incidence scores

The aim was to construct and illustrate the use of diagnostic standards for recording of DFS incidence. Separate standards are presented for ranking of subjects; the mean "intermediate" DFS score per subject, which represented the majority decision of three dentists; and a certainty scale for individual tooth surfaces. The scores recorded for 40 sets of posterior bitewing radiographs of children between 13 and 15 years of age by two fourth year dental students and two dental hygienists were compared with the standards. Spearman's rank correlation coefficient reached the critical level of +0.70 in three of eight instances. Only one mean net DFS increment score differed significantly from the mean standard score (p less than 0.05). The level of agreement with the certainty scale for individual surfaces was low. Focusing attention on recording of DFS incidence gives a more severe test of examiners' diagnostic performance. The construction and use of control charts for monitoring the diagnostic level of examiners is suggested.