Helicobacter pylori Infection in Gastroesophageal Reflux Disease in the Asian Countries

Table 1

Recent epidemiologic studies for association between H. pylori infection and GERD.

Study [references]	Type of study	Location	Number of cases in each group ()	H. pylori infection assessments	H. pylori prevalence (%) in each group
Chung et al. 2011 [30]	Case-control	Korea	Reflux esophagitis (2,808); Control (2,808)	Serology	Reflux esophagitis (38.4); Control (58.2)
Gunji et al. 2011 [31]	Cross-sectional	Japan	Erosive esophagitis (1,831); No erosive esophagitis (8,009)	Serology	Erosive esophagitis (13.6); No erosive esophagitis (33.4)
Chiba et al. 2012 [32]	Cross-sectional	Japan	Erosive esophagitis (728); No erosive esophagitis (4,262)	Serology	Erosive esophagitis (9.4); No erosive esophagitis (14.9)
Ashktorab et al. 2012 [33]	Case-control	USA	Reflux esophagitis (58); Gastritis (1,558); Reflux esophagitis and gastritis (363); Normal control (41)	Biopsy silver stain or immunohistochemistry	Reflux esophagitis (3.8); Gastritis (40); Reflux esophagitis and gastritis (34); Normal control (34)
Sonnenberg et al. 2010 [34]	Cross-sectional	USA	Barrett’s esophagus (2,510); No Barrett’s esophagus (76,475)	Biopsy immunohistochemistry	Barrett’s esophagus (5.7); No Barrett’s esophagus (12.2)
Thrift et al. 2012 [35]	Case-control	Australia	Simple Barrett’s esophagus (217); Dysplastic Barrett’s esophagus (95); Control (398)	Serology	Simple Barrett’s esophagus (12); Dysplastic Barrett’s esophagus (3); Control (18)

GERD: gastroesophageal reflux disease.