Grades of esophagogastroduodenoscopy (EGD) and computed tomography (CT) in differentiating group C2 (requiring operation) and group C3 (not requiring operation). The “most severe EGD/CT grades” refers to the most severe grade among the esophagus, stomach, and duodenum in each patient under EGD (Zargar’s 0, 1, 2a, 2b, 3a, 3b) and CT (grades 1, 2, 3, 4), respectively. The “combination of EGD + CT grades” is calculated by EGD (Zargar’s 0, 0 point; Zargar’s 1, 1 point; Zargar’s 2a, 2 points; Zargar’s 2b, 3 points; Zargar’s 3a, 4 points; Zargar’s 3b, 5 points) plus CT (grade 1, 1 point; grade 2, 2 points; grade 3, 3 points; grade 4, 4 points). Hence, the “combination of EGD + CT grades” ranges from 1 to 9 points. Abbreviations: AUROC, area under the receiver operating characteristic curve; CI, confidence interval; CT, computed tomography; EGD, esophagogastroduodenoscopy.