Risk of pyogenic liver abscess and endoscopic sphincterotomy: a population-based cohort study

OBJECTIVES: To evaluate the risk of pyogenic liver abscess (PLA) in patients receiving endoscopic sphincterotomy (ES). SETTING: A population-based cohort study using data from Taiwans’ National Health Insurance Research Database was conducted. Patients aged 20 or older who had undergone an ES were considered as the ES cohort. The dates for the first hospitalisation of the patients receiving ES were defined as the index dates. PARTICIPANTS: Patients in the ES and non-ES cohorts were selected by 1:1 matching ratio based on a propensity score. A total of 8174 sex-matched, age-matched and index year-matched (1:1) pairs of patients receiving ES and 8174 patients without ES served as controls. Cox proportional hazards regression was employed to calculate the HRs and 95% CIs for the association between PLA and ES. RESULTS: The overall incidence of PLA was significantly higher in the ES cohort than in the non-ES cohort (4.20 vs 0.94, respectively, per 1000 person-year) with the adjusted HR (aHR) 4.50 (95% CI 3.38 to 6.58) A stratified analysis during the follow-up years revealed that when the ES cohort was compared with the non-ES cohort, they displayed a higher risk of PLA during the first follow-up year (aHR 4.35, 95% CI 2.26 to 8.39) which continued significantly over the next 4–5 years of follow-up. CONCLUSIONS: Patients receiving ES are associated with having a higher risk of PLA.