Table 2 Cohen’s and Fleiss’ kappa scores for grading of non-invasive urothelial carcinoma of the bladder. Individual pathologist grades and pathologist consensus grades compared (top) between 1st and 2nd glass slide grading sessions and between glass slide (1st grading) and digital pathology grading. Agreement between all three pathologists (below) are given for both glass slide grading sessions and digital pathology grading. Both 1973 and 2004 grading systems compared
|  | WHO 1973 1st vs. 2nd glass grading (Cohen’s kappa, linear weighted) | WHO 2004 1st vs. 2nd glass grading (Cohen’s kappa, linear weighted) | WHO 1973 Glass vs. digital grading (Cohen’s kappa, unweighted) | WHO 2004 Glass vs. digital grading (Cohen’s kappa, unweighted) |
|---|---|---|---|---|
Pathologist A | 0.55 | 0.64 | 0.70 | 0.74 |
Pathologist B | 0.46 | 0.83 | 0.77 | 0.82 |
Pathologist C | 0.78 | 0.70 | 0.77 | 0.53 |
Consensus | 0.71 | 0.83 | 0.82 | 0.78 |
|  | 1973 (Fleiss’ kappa) | 2004 (Fleiss’ kappa) |  |  |
Agreement of all three pathologists on 1st glass grading | 0.49 | 0.56 | Â | Â |
Agreement of all three pathologists on 2nd glass grading | 0.56 | 0.70 | Â | Â |
Agreement of all three pathologists on digital grading | 0.44 | 0.61 | Â | Â |