Table 1. Characteristics of the included studies.

Study	Country	Number of patients	Mean age (years)	M/F	Endoscopy type	Endoscopy mode	Magnification factor	Observed site	Diagnostic classification
Yagi K et al. 2002 [14]	Japan	94	—	—	Olympus, GIF-Q240Z	WLE	×80	Antrum	wDRP, iDRP
Yagi K et al. 2002 [15]	Japan	297	47	145/152	Olympus, GIF-Q240Z	WLE	×80	Corpus	Z0-3
Nakagawa S et al. 2003 [16]	Japan	92	55.6	56/36	Olympus, GIF-Q240Z	WLE	×80	Antrum/Corpus	R.I.O
Yang JM et al. 2003 [17]	China	140	50.6	68/72	Olympus, GIF-Q240Z	WLE	×80	Corpus	R.I.D
Egi Y et al. 2006 [18]	Japan	44	—	—	Fujinon, EG-450ZW5	indigo carmine	×100	Cardia	Fundic and nonfundic type
Anagnostopoulos GK et al. 2007 [19]	UK	95	58.6	52/43	Olympus, GIF-Q240Z	WLE	×115	Corpus	Type1-3
Bansal A et al. 2008 [20]	USA	47	65	46/1	Olympus, GIF 240Z	NBI	×115	Antrum and corpus	irregular pattern with decreased density of vessels
Gonen C et al. 2009 [21]	Turkey	129	48.6	32/97	Fujinon, EG-490ZW5	WLE/indigo carmine	×100	Corpus/Antrum	Z0-3/CZ0-2/wDRP, iDRP/CZA0-2
Tahara T et al. 2009 [22]	Japan	106	58.7	64/42	Olympus, GIF-H260Z	NBI	×85	Corpus	Normal+Type1-3
Qi QQ et al. 2013 [23]	China	84	49.3	47/37	Pentax, EG-2990Zi	WLE/i-scan	×100	Corpus	Type1-3
Kawamura M et al. 2013 [24]	Japan	175	63.9	116/59	Olympus, Model Q240Z or H260Z	WLE	—	Corpus	COs
Liu H et al. 2014 [25]	China	90	57.5	49/41	Olympus, Model GIF H260Z	NBI	×70	Antrum	Type A-E

All included studies are prospective trials. WLE, white light endoscopy; NBI, narrow band imaging. The details of different diagnostic classifications is listed in S1 Text.