Selection criteria for preoperative endoscopic retrograde cholangiopancreatography before laparoscopic cholecystectomy and endoscopic treatment of bile duct stones: Results of a retrospective, single center study between 1996-2002

Table 8 Predictive value of predictive factors according to the number of positive factors

Number of positive factors	Number	PPV %	NPV %	Sensitivity %	Specificity %
1	84	1.2	-	-	-
2	46	43.1	98.7	95.2	76.1
3	40	72.5	84.0	59.1	90.5
≥ 4	36	91.4	72.0	40.2	98.4

P < 0.00001 for the whole group, P < 0.00001, between group 1 and groups 2, 3, 4 and group 2 and group 4, P = 0.008, between groups 2 and 3, P = 0.035, between groups 3 and 4.