(a) The data of Helicobacter pylori infection in esophageal squamous cell carcinoma

First author	Year	Esophageal squamous cell carcinoma				Hp
		Case		Control
		Hp+	Hp-	Hp+	Hp-	Test method
Talley et al.	1991	20	21	96	156	S
Henrik et al.	2001	10	19	67	82	S
El-Omar et al.	2003	31	22	84	126	S
Wang et al.	2003	33	30	145	165	S
Ye et al.	2004	32	53	198	301	S
Wu et al.	2005	28	99	74	97	S
Kamangar et al.	2007	254	81	662	330	S
Iijima et al.	2007	60	13	56	17	S, H, U
Simán et al.	2007	15	22	68	61	S
Wu et al.	2009	112	205	563	540	S
Hu et al.	2009	66	114	102	92	S
Whiteman et al.	2010	54	154	302	1,014	S
Cook et al.	2010	64	14	71	20	S
Venerito et al.	2011	53	22	53	22	S, H, U
Khoshbaten et al.	2011	58	42	83	17	S
Murphy et al.	2012	64	18	63	19	S
Xue et al.	2013	7	3	988	503	S
Obayo et al.	2015	14	3	69	5	U
Poyrazoglu et al.	2017	66	30	128	23	U
Tseng et al.	2017	12	25	3,638	12,541	S, H, U
Vohlonen et al.	2018	6	14	6,178	5,232	S

Note: Hp: Helicobacter pylori; S: serology; H: histology; U: rapid urease test.