Kim SY, et al. - Objectives of this study were to compare the efficacy of sequential and concomitant therapies as for the first-line treatments for Helicobacter pylori (H. pylori) eradication and to examine the impacts of clarithromycin resistance on the eradication rates. For H. pylori eradication, concomitant therapy was superior to sequential therapy as the first-line treatment, particularly in clarithromycin-resistant strains in Korea.