Table 1. Intra- and inter-observer variability of CCIC method analyzed by Bland-Altman plots with mean difference and level of agreement (LoA).
| DRG | Observer 1 | Observer 2 | P | Mean bias (95% CI) |
|---|---|---|---|---|
| Mean (SD) | Mean (SD) | (Two-sided) | ||
| Inter-observer variability | ||||
| 1 | 12.18 (12.21) | 11.82 (11.97) | 0.371 | 0.36 (−2.157 to 2.885) |
| 2 | 7.091 (6.534) | 7.182 (6.615) | 0.67 | −0.09 (−1.46 to 1.28) |
| 3 | 31.09 (7.867) | 28.82 (7.167) | <0.001 | 2.27 (0.11 to 4.43) |
| 4 | 30.82 (24.71) | 29.64 (23.75) | 0.01 | 1.18 (−1.27 to 3.63) |
| 5 | 58.00 (38.60) | 55.36 (37.27) | 0.01 | 2.63 (−1.77 to 7.04); |
| 6 | 46.18 (17.39) | 43.73 (15.82) | 0.02 | 2.46 (−3.05 to 7.95) |
| 7 | 50.09 (37.43) | 47.27 (34.94) | <0.01 | 2.82 (−2.50 to 8.14) |
| 8 | 11.45 (12.32) | 10.82 (10.59) | 0.36 | 0.64 (−3.68 to 4.96) |
| 9 | 12.73 (18.52) | 12.64 (17.99) | 0.80 | 0.09 (−2.14 to 2.32) |
| 10 | 31.36 (22.82) | 31.36 (22.82) | 1.0 | 0.00 (−2.32 to 2.32) |
| 11 | 23.00 (27.01) | 21.36 (25.55) | 0.01 | 1.64 (−1.68 to 4.95) |
| 12 | 9.909 (7.231) | 9.727 (6.944) | 0.62 | 0.18 (−2.11 to 2.47) |
| Intra-observer 1 variability | ||||
| DRG | First Analysis | Second Analysis | P | Mean bias (95% CI) |
| Mean (SD) | Mean (SD) | (Two-sided) | ||
| 1 | 12.18 (12.21) | 12.18 (12.15) | 1.0 | 0.00 (−1.24 to 1.24) |
| 2 | 7.091 (6.534) | 6.909 (6.457) | 0.17 | 0.18 (−0.61 to 0.97 |
| 3 | 31.09 (7.867) | 30.27 (6.987) | 0.04 | 0.82 (−1.47 to 3.11) |
| 4 | 30.82 (24.71) | 30.0 (24.12) | 0.03 | 0.82 (−1.30 to 2.93) |
| 5 | 58.00 (38.60) | 57.27 (37.80) | 0.02 | 0.73 (−2.56 to 4.02) |
| 6 | 46.18 (17.39) | 44.27 (16.40) | 0.01 | 1.91 (−1.65 to 5.47) |
| 7 | 50.09 (37.43) | 48.36 (36.66) | 0.04 | 1.73 (−2.84 to 6.29) |
| 8 | 11.45 (12.32) | 11.00 (11.78) | 0.10 | 0.45 (−1.15 to 2.06) |
| 9 | 12.73 (18.52) | 12.18 (17.09) | 0.34 | 0.55 (−3.00 to 4.09) |
| 10 | 31.36 (22.82) | 31.64 (23.05) | 0.57 | −0.27 (−3.30 to 2.78) |
| 11 | 23.00 (27.01) | 22.27 (26.35) | 0.07 | 0.73 (−1.61 to 3.06) |
| 12 | 9.909 (7.231) | 9.727 (6.944) | 0.34 | 0.18 (−1.00 to 1.36) |
| Intra-observer 2 variability | ||||
| DRG | First Analysis | Second Analysis | P | Mean bias (95% CI) |
| Mean (SD) | Mean (SD) | (Two-sided) | ||
| 1 | 11.82 (11.97) | 11.64 (12.02) | 0.5 | 0.18 (−1.53 to 1.90) |
| 2 | 7.182 (6.615) | 7.091 (6.441) | 0.77 | 0.09 (−2.14 to 2.31) |
| 3 | 28.82 (7.167) | 27.36 (7.366) | 0.04 | 1.46 (−2.60 to 5.50) |
| 4 | 29.64 (23.75) | 29.09 (23.41) | 0.11 | 0.55 (−1.49 to 2.58) |
| 5 | 55.36 (37.27) | 54.91 (36.50) | 0.48 | 0.45 (−3.60 to 4.51) |
| 6 | 43.73 (15.82) | 43.36 (15.81) | 0.44 | 0.36 (−2.58 to 3.30) |
| 7 | 47.27 (34.94) | 46.36 (34.21) | 0.13 | 0.91 (−2.65 to 4.47) |
| 8 | 10.82 (10.59) | 10.64 (11.08) | 0.5 | 0.18 (−1.53 to 1.90) |
| 9 | 12.64 (17.99) | 12.55 (17.87) | 0.72 | 0.09 (−1.54 to 1.72) |
| 10 | 31.36 (22.82) | 30.55 (21.83) | 0.15 | 0.82 (−2.56 to 4.19) |
| 11 | 21.36 (25.55) | 20.73 (24.19) | 0.39 | 0.64 (−3.94 to 5.20) |
| 12 | 9.727 (6.944) | 9.818 (7.097) | 0.76 | −0.09 (−1.94 to 1.76) |
Note: P values were calculated by 2-sided paired t-test. Limits of agreement were set as mean difference ±1.96 × SD. Upper and lower limits of agreement indicate 95% confidence range.