Table 2 Calculation of the interobserver agreement (kappa coefficient)
From: Is overexpression of HER-2 a predictor of prognosis in colorectal cancer?
| Pathologist 2 | Total | |||||
|---|---|---|---|---|---|---|
| 1+ | 2+ | 3+ | 1.00 | |||
| Pathologist 1 | 1+ | Count (n) | 7 | 1 | 0 | 8 |
| Pathologist 1 (%) | 87.5 | 12.5 | 0 | 100 | ||
| Pathologist 2 (%) | 100 | 11.1 | 0 | 44.4 | ||
| % of Total | 38.9 | 5.6 | 0 | 44.4 | ||
| 2+ | Count (n) | 0 | 8 | 0 | 8 | |
| Pathologist 1 (%) | 0 | 100 | 0 | 100 | ||
| Pathologist 2 (%) | 0 | 88 | 0 | 44.4 | ||
| % of Total | 0 | 44 | 0 | 44.4 | ||
| 3+ | Count (n) | 0 | 0 | 2 | 2 | |
| Pathologist 1 (%) | 0 | 0 | 100 | 100 | ||
| Pathologist 2 (%) | 0 | 0 | 100 | 11.1 | ||
| % of Total | 0 | 0 | 11.1 | 11.1 | ||
| Total | Count (n) | 7 | 9 | 2 | 18 | |
| Pathologist 1 (%) | 38.9 | 50 | 11.1 | 100 | ||
| Pathologist 2 (%) | 100 | 100 | 100 | 100 | ||
| % of Total | 38.9 | 50 | 11.1 | 100 | ||
| Symmetric measures | ||||||
| Value | Standard error (a) | Approximate T (b) | Approximate significance | |||
| Kappa coefficient | 0.906 | 0.092 | 4.894 | 0.00 | ||
| Number of valid cases (n) | 18 | |||||