), with or without bismuth, in the same prescription order, with a treatment duration of 7-14 days (Supporting Table 2). The information on medications was retrieved from the pharmacy prescription database, a subpart of the NHIRD containing details of every prescription including dosage, frequency, starting and ending days, total number of pills, and administration routes. Reliability of the retrieved buy GS-1101 information was verified
independently by two statisticians. Because death usually results from the underlying illness that may also affect the risk of PUB, its occurrence leads to informative censoring in estimating the rebleeding incidence. Therefore, death occurring prior to recurrent bleeding was considered a competing risk event in analysis. The death-adjusted cumulative incidences of recurrent PUB
were calculated using a two-step process and were tested for equality between the two cohorts.19, 20 After confirming the assumption of proportional hazards (Supporting Fig. 1), we applied the modified Cox proportional hazard model in the presence of competing risk event to examine the independent association between cirrhosis and peptic ulcer rebleeding.21, 22 The influence of cirrhosis on PUB recurrence was further explored in different strata according to age, sex, comorbidity, therapeutic agents, and H. pylori status. We defined users of a certain medication Selleckchem Protease Inhibitor Library if the drug duration
was longer than 10% of the observation period. Moreover, we analyzed whether alcoholic etiology or prior episode of AVH confounded the rebleeding risk in patients with cirrhosis. SAS version 9.2 (SAS Institute., Cary, NC) was applied for data management, and R software with package cmprsk_2.1-4 (by Robert J. Gray; http://biowww.dfci.harvard.edu/∼gray/) was used to calculate the cumulative incidence and hazard ratio (HR) in the competing risk analysis. Calculated results were expressed with the estimated number together with the 95% confidence interval (CI). All statistical tests were two-sided, with significance set at P < 0.05. We identified a total of 9,711 patients with liver cirrhosis among 271,030 patients who were hospitalized for the first GNA12 time with a primary diagnosis of PUB between 1997 and 2006. This cohort was matched with 38,844 PUB patients without cirrhosis in terms of age, sex, and use of antisecretory agents. Demographic data, H. pylori status, drugs that might protect or induce peptic ulcers, propranolol, major comorbidities, and follow-up duration of the two cohorts are summarized in Table 1. Using the Kaplan–Meier approach without accounting for competing risk events, the 10-year cumulative incidences of recurrent bleeding were 43.7% (95% CI, 41.0-46.3%) and 31.4% (95% CI, 30.6-32.2%), respectively, in patients with cirrhosis and matched controls (P < 0.0001) (Fig. 1A).