Table 4.

Cox proportional hazard regression analysis for the risk of pyogenic liver abscess by endoscopic sphincterotomy and cholangitis

Variables		Event	Person-years	Rate†	Adjusted HR‡ (95% CI)	P value
Endoscopic sphincterotomy	Cholangitis					0.03
No	No	25	32 177	0.78	1 (reference)
No	Yes	8	2936	2.72	3.77 (1.69 to 8.41)**
Yes	No	122	30 378	4.02	5.48 (3.56 to 8.44)***
Yes	Yes	27	5076	5.32	6.64 (3.82 to 11.5)***

*P<0.05, **P<0.01, ***P<0.001.

†Per 1000 person-year.

‡Model was adjusted for age, sex and other comorbidities.