Table 1. Characteristics of studies included in the meta-analysis.

				Prevention Group					Control Group
Studies	Risk Factor	Co-administration	Course	n	Drug	Usage	Ulcer/ Erosion(%)	Bleeding (%)	n	Drug	Usage	Ulcer/ Erosion(%)	Bleeding (%)
Ng 2010[48]	Ulcer or erosions	no	48w	65	pantoprazole	20 mg bid	0 (0)	0 (0)	65	famotidine	40mg bid	8 (12.3)	5 (7.7)
Ng 2012[49]	ACS or MI	Clopidogrel and anticoagulant	4-52w	163	esomeprazole	20 mg qd	1 (0.6)	3 (1.8)	148	famotidine	40 mg qd	6 (4.1)	12 (8.1)
Yano 2012[50]	ACS	Clopidogrel	12m	65	Omeprazole	10 mg qd	-	3(4.6)	65	famotidine	20 mg qd	-	1(1.5)
Guo M 2009[51]	Not clear	no	90d	42	Omeprazole or esomeprazole	20 mg qd	6 (14.3)	-	22	famotidine	20 mg bid	5 (22.7)	-
Sun RR 2012[52]	Elders	no	90d	40	rabeprazole	20 mg qd	3 (7.5)	0 (0)	40	ranitidine	150mg bid	11 (27.5)	1(2.5)
Wang YP 2012[53]	HP-, no ulcer history	no	90d	23	lansoprazole	30 mg qd	2 (8.7)	0 (0)	22	famotidine	20 mg bid	6 (27.3)	1(4.5)
Hu L 2012[54]	Not clear	no	90d	50	rabeprazole	10 mg qd	5(10)	-	48	famotidine	20 mg bid	9 (18.8)	-
Lu BJ 2013[55]	ACS	Clopidogrel	30d	50	omeprazole	40mg qd	-	2(4)	50	ranitidine	150 mg bid	-	9(18)
Wang J 2012[56]	ACS	Clopidogrel	90d	43	esomeprazole	20mg bid	3 (7.0)	-	46	famotidine	20 mg bid	5 (10.9)	-

ACS:acute coronary syndrome; MI:myocardial infarction