Table 2.
ROC analysis of baseline parameters for predicting glucose intolerance (DM/IFG/IGT) before surgery, and parameters for predicting improvement of glucose tolerance status after surgery.
| Parameters | AUC | P value | 95%CI | Cut–off value | Sensitivity | Specificity | PPV | NPV |
|---|---|---|---|---|---|---|---|---|
| ROC analysis of risk factors for predicting glucose intolerance (dm/ifg/igt) before surgery | ||||||||
| Disposition Index (DI) | 0.115* | 0.000 | 0.030–0.201 | – | – | – | – | – |
| Predictor−1 | 0.885 | 0.000 | 0.799–0.970 | 0.866 | 71.2% | 91.7% | 97.4% | 42.3% |
| ROC analysis of parameters for predicting improvement of glucose tolerance status after surgery | ||||||||
| FCP (ng/ml) | 0.709 | 0.019 | 0.558–0.860 | 2.445 | 69.5% | 89.2% | 86.6% | 74.5% |
| Disposition Index (DI) | 0.465* | 0.046 | 0.273–0.656 | – | – | – | – | – |
| Predictor−2 | 0.252* | 0.005 | 0.112–0.393 | – | – | – | – | – |
AUC, areas under the curve; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value; FCP, fasting C-peptide.
*
These parameters were excluded due to their AUC < 0.5.
Predictor is the predicted value calculated by the prediction model using logistic regression analysis.