Risk factors for prolonged postoperative ileus in elderly patients undergoing laparoscopic radical resection for colorectal cancer

Figure 2 Receiver operating characteristic curves and area under the curve for predicting prolonged postoperative ileus in elderly patients with colorectal cancer. A: Receiver operating characteristic (ROC) curves and area under the curve (AUC) values on the basis of an modified 5-item Frailty Index (mFI-5) ≥ 2, postoperative opioid use, and low serum potassium on postoperative day 1 (POD 1); B: ROC curves and AUC values of mFI-5 ≥ 2; C: ROC curves and AUC values of postoperative opioid use; D: ROC curves and AUC values of serum potassium concentration on POD 1 < 3.61 mmol/L. AUC: Area under the curve; CI: Confidence interval.