“…We excluded 540 articles due to the following reasons: editorial ( n = 3), meta‐analysis ( n = 6), review article ( n = 22), title and abstract showed not relevant ( n = 224), duplicate ( n = 153), outlying islands of Taiwan (n = 9), in gastric cancer group ( n = 7), in group with specific diseases ( n = 36), no data of H. pylori prevalence ( n = 67), in specific age group ( n = 4), or children and adolescents ( n = 9). Subsequently, we added the unpublished data of the present study and excluded 13 ineligible articles after review of full texts and one article which there was no full‐text available for identification, and the remaining 29 clinical articles were eligible 17–44 . The information of each study including data collecting period, participants, setting, study site, mean or range of age, numbers of H. pylori positivity, numbers of study participants was shown in Table .…”