Two observers (A and B) had evaluated the same material 15 years earlier. Comparisons between earlier and present findings revealed 83% intraobserver agreement for both of them, with kappa values 0.54 and 0.57. The corresponding interobserver figures were 83% and 0.53.
The observersâ€™ findings are presented in Table 1 together with the results after the joint evaluation of disagreement and difficult, borderline cases. Details regarding the latter cases are presented below.
Agreement between all observers was found for 73% of the roots.
The two original observers now had an interobserver agreement of 86%, kappa 0.61. The new endodontistâ€™s evaluation was close to those of the two original examiners. The agreement of A vs. C was 85%, kappa 0.58, and the agreement for B vs. C was 82%, kappa 0.55.
Table 1. Periapical findings by three observers separately evaluating 257 endodontically treated roots, compared with the results after joint evaluation of disagreement cases and selected difficult, borderline cases. Results presented as percentages.
Disagreement and difficult borderline cases.
A total of 32 cases (12%) were subjected to joint discussion. Three cases (1%) had been given different diagnoses by the three observers. Eight rejections, either by the two endodontists (A and C) or by the radiologist (B) alone, were reevaluated. Twenty-one cases were selected as being suitable for discussion amongst the cases with initial agreement between the two observers.
Final agreement about the diagnoses was obtained for all cases except seven rejections that were maintained. The diagnoses for six of the 21 selected cases, with initial agreement between the two observers, were changed after discussion between all three observers. Analyses of the data did not indicate that any of the observers had a special influence on the joint decisions.