['Patients with liver cirrhosis (LC) often develop peptic ulcers. The differentiation of Helicobacter pylori etiology in LC patients from that of peptic ulcers in non-LC patients is critical. This study aimed to determine whether H. pylori plays a central role in LC patients with peptic ulcers.', 'LC was defined by International Classifications of Diseases, Revision 9, and Clinical Modification (ICD-9-CM) codes 571.2, 571.5, and 571.6. To be defined as non-LC, we did not identify patients in an inpatient setting or by one or more ambulatory care claims containing the International Classifications of Diseases, Revision 9, and Clinical Modification codes 571.2, 571.5, and 571.6. The sample included 9465 H. pylori-positive patients and 3418 H. pylori-negative patients. A logistic regression model was used to calculate the odds ratio (OR) and a 95% confidence interval was used to determine whether LC was an independent factor of lower H. pylori infection rates in peptic ulcer patients.', 'This study included 102 decompensated LC patients with peptic ulcers, 39 H. pylori-positive and 63 H. pylori-negative. There were 360 compensated LC patients with peptic ulcers, 193 H. pylori-positive and 167 H. pylori-negative. Among the non-LC patients with peptic ulcers, 9233 were H. pylori-positive and 3188 were H. pylori-negative. On the basis of logistic regression analysis, decompensated LC patients (OR=0.23, P<0.001) and compensated LC patients (OR=0.48, P<0.001) had lower H. pylori infection rates.'] Is helicobacter pylori the predominant etiology for liver cirrhosis patients with peptic ulcer disease?