Endoscopic submucosal dissection for early gastric cancer with undifferentiated-type histology: A meta-analysis

Table 4 Methodological quality of included studies measured by Newcastle-Ottawa scale

Ref.	Selection	Comparability	Exposure or outcome	Total
Kim et al[23], 2009	4	1	2	7
Kang et al[24], 2010	4	1	2	7
Lee et al[25], 2010	4	2	2	8
Yamamoto et al[26], 2010	4	1	3	8
Goh et al[27], 2011	3	1	2	6
Park et al[28], 2012	3	1	3	7
Kamada et al[29], 2012	4	1	3	8
Okada et al[30], 2012	4		3	7
Park et al[31], 2013	4	2	2	8
Choi et al[32], 2013	4	2	3	9
Kim et al[33], 2013	4	1	3	8
Abe et al[34], 2013	4	1	3	8
Chung et al[35], 2014	3	2	3	8
Oka et al[36], 2014	3	1	3	7