Cholecystectomy reduces subsequent cholangiocarcinoma risk in choledocholithiasis patients undergoing endoscopic intervention

Table 2 Incidence of cholangiocarcinoma among patients with choledocholithiasis who underwent therapeutic endoscopic retrograde cholangiopancreatography, endoscopic retrograde cholangiopancreatography and cholecystectomy, or no intervention compared with normal population (excluding cholangiocarcinoma in the first 18 mo)

Variable	Person-years at risk in study cohort	Person-years at risk in control cohort	No. of observed cases of cholangiocarcinoma in study cohort	No. of observed cases of cholangiocarcinoma in control cohort	Incidence rate/1000 person-years (95%CI) in study cohort	Incidence rate/1000 person-years (95%CI) in control cohort	P value
ES/EPBD
Total	1659.70	25360.07	12	7	7.23 (3.92-12.29)	0.28 (0.12-0.55)	< 0.001
Gender
Male	889.95	13822.88	4	3	4.50 (1.43-10.84)	0.22 (0.06-0.59)	< 0.001
Female	769.76	11537.20	8	4	10.39 (4.83-19.74)	0.35 (0.11-0.84)	< 0.001
Age, years
18-49	253.84	4392.03	1	0	3.94 (0.20-19.43)	0.00 (0.00-0.00)	< 0.001
50-69	574.78	8631.76	4	5	6.96 (2.21-16.79)	0.58 (0.21-1.28)	< 0.001
> 70	831.08	12336.28	7	2	8.42 (3.68-16.66)	0.16 (0.03-0.54)	< 0.001
ES/EPBD and CCY
Total	393.11	25360.07	1	7	2.54 (0.13-12.55)	0.28 (0.12-0.55)	0.011
Gender
Male	184.36	13822.88	0	3	0.00 (0.00-0.00)	0.22 (0.06-0.59)	0.842
Female	208.75	11537.20	1	4	4.79 (0.24-23.63)	0.35 (0.11-0.84)	0.002
Age, yr
18-49	113.01	4392.03	0	0	0.00 (0.00-0.00)	0.00 (0.00-0.00)	NA
50-69	143.37	8631.76	1	5	6.98 (0.35-34.40)	0.58 (0.21-1.28)	0.004
> 70	136.73	12336.28	0	2	0.00 (0.00-0.00)	0.16 (0.03-0.54)	0.882
Without intervention
Total	4364.45	25360.07	11	7	2.52 (1.35-4.38)	0.28 (0.12-0.55)	< 0.001
Gender
Male	2345.22	13822.88	6	3	2.56 (1.04-5.32)	0.22 (0.06-0.59)	< 0.001
Female	2019.23	11537.20	5	4	2.48 (0.91-5.49)	0.35 (0.11-0.84)	< 0.001
Age, yr
18-49	871.87	4392.03	0	0	0.00 (0.00-0.00)	0.00 (0.00-0.00)	NA
50-69	1528.74	8631.76	6	5	3.93 (1.601-8.16)	0.58 (0.21-1.28)	< 0.001
> 70	1963.84	12336.28	5	2	2.55 (0.93-5.64)	0.16 (0.03-0.54)	< 0.001

ES: Endoscopic sphincterotomy; EPBD: Endoscopic papillary balloon dilatation; CCY: Cholecystectomy; NA: Not applicable.