Consistency of Helicobacter pylori eradication rates of first-line concomitant and sequential therapies in Korea: A nationwide multicenter retrospective study for the last 10 years.

Concomitant therapy is the best regimen for the first-line H. pylori eradication showing consistently higher eradication rate with an increasing trend for the last 10 years in Korea. Bismuth quadruple therapy should be considered for second-line therapy after eradication failure using non-bismuth quadruple therapy.