Ka Shing Cheung, M.B.B.S., M.P.H., from The University of Hong Kong, and colleagues gathered data from 46,460 patients in Hong Kong who were aged 45 years or older and had received clarithromycin-based triple therapy for H. pylori infection, consisting of a proton pump inhibitor prescribed with clarithromycin and either amoxicillin or metronidazole. Patients were followed for a median...