Table 4.

Quality assessment of eligible studies for clinical parameter analysis and prognosis analysis according to the Newcastle-Ottawa Scale.

Study	Selection			Comparability				Outcome		Total
	Adequacy of case definition	Number of case	Representativeness of the cases	Ascertainment of relevant cancers		Ascertainment of detection method	circRNA expression	Assessment of outcome	Adequate follow-up
Wang et al.	1	1	1		1	1	1	0	0	6
Liu et al.	1	1	1		1	1	1	1	1	8
Huang et al.	1	1	1		1	1	1	1	0	7
Tao et al.	1	1	1		1	1	1	1	0	7
Wang et al.	1	1	1		1	1	1	1	1	8
Li et al.	1	1	1		1	1	1	1	1	8
Shi et al.	1	0	1		1	1	1	1	0	7
Huang et al.	1	1	1		1	1	1	1	1	8
Chao et al.	1	1	1		1	1	1	0	0	6
Song et al.	1	1	1		1	1	1	0	0	6
Li et al.	1	1	1		1	1	1	1	0	7
Liu et al.	1	1	1		1	1	1	1	0	7
Cai et al.	1	1	1		1	1	1	1	0	7
Wang et al.	1	1	1		1	1	1	0	0	6
Chen et al.	1	1	1		1	1	1	1	1	8
Huang et al.	1	1	1		1	1	1	1	0	7
Dong et al.	1	1	1		1	1	1	1	1	8
Hu et al.	1	1	1		1	1	1	1	1	8
Liu et al.	1	1	1		1	1	1	1	0	7
Gao et al.	1	1	1		1	1	1	1	1	8