Table 2.
Correspondence between probabilities of gangrenous cholecystitis versus those obtained from Yacoub's model
| Score | Na | Actual probability | Predicted probability (prediction interval)b |
|---|---|---|---|
| 0 | 49 | 0.02 | 0.03 (0.02–0.06) |
| 1 | 105 | 0.06 | 0.06 (0.04–0.09) |
| 1.5 | 10 | 0.10 | 0.07 (0.05–0.11) |
| 2 | 94 | 0.12 | 0.09 (0.07–0.13) |
| 2.5 | 18 | 0.17 | 0.12 (0.09–0.16) |
| 3 | 45 | 0.09 | 0.15 (0.12–0.19) |
| 3.5 | 25 | 0.24 | 0.19 (0.15–0.24) |
| 4 | 60 | 0.20 | 0.24 (0.19–0.29) |
| 4.5 | 29 | 0.28 | 0.29 (0.23–0.36) |
| 5 | 11 | 0.36 | 0.35 (0.27–0.44) |
| 5.5 | 21 | 0.48 | 0.41 (0.31–0.52) |
| 6.5 | 11 | 0.55 | 0.55 (0.41–0.69) |
a
N = number of patients with each score. In all, 478 patients had complete data for all four variables.
b
P-value for the chi-square goodness of fit for the model = 0.95.