Table 3.

Trends of pyogenic liver abscess risks by stratified follow-up years

Follow-up time, years	Endoscopic sphincterotomy						Crude HR‡ (95% CI)	Adjusted HR§ (95% CI)
	No			Yes
	Event	Person-years	Rate†	Event	Person-years	Rate†
1–2	11	15 458	0.71	52	15 319	3.39	4.81 (2.51 to 9.23)***	4.35 (2.26 to 8.39)***
2–3	15	9931	1.51	52	9785	5.31	3.54 (1.99 to 6.28)***	3.64 (2.04 to 6.50)***
4–5	5	5512	0.91	22	5692	3.87	4.27 (1.62 to 11.3)**	4.59 (1.72 to 12.2)**
>5	2	4213	0.47	23	4658	4.94	10.4 (2.45 to 44.0)**	12.1 (2.80 to 52.2)***

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

†Incidence rate, per 1000 person-years.

‡Relative HR.

§Adjusted HR, adjusted for age, sex and comorbidity of congestive heart failure, biliary stone, cancer, hypertension, chronic obstructive lung disease, hyperlipidaemia, alcoholic liver damage, cirrhosis, cholangitis, cholecystitis, pancreatic diseases, chronic kidney disease, appendicitis, inflammatory bowel disease and diverticulosis.