Performance of predictive variables for anticipating difficult surgery
| Predictive variable | Cut-off value | Sensitivity | Specificity |
| BMI | 45 kg/m2 | 38% | 89% |
| Visceral obesity measurement | 14.3 cm | 54% | 91% |
| DRM | 4.43 | 62% | 93% |
BMI, body mass index; DRM, difficulty risk model.