Fig. 3From: Systematic review of time trends in the prevalence of Helicobacter pylori infection in China and the USAMean prevalence estimates (weighted by sample size) of Helicobacter pylori infection for Chinese datasets with study midpoints before, and after, the mean of all study midpoints, according to the assay method used and whether or not patients were living in urban or rural areas. IgG immunoglobulin GBack to article page