Table 2.

NOs score of studies included in the systematic review and meta-analysis

Study	Selection	Comparability	Outcome/Expose	Total score
Wang L et al.	3	2	2	7
Jiang W et al.	4	1	2	7
Zhao J et al.	4	2	2	8
Marshall EG et al.	4	1	2	7
Hansen CA et al.	4	1	2	7
Zhu Y et al.	3	1	2	6
Zhou Y et al.	4	2	2	8
Hwang BF et al.	4	1	2	7
Liu FH et al.	4	2	2	8
Gilboa SM et al.	3	2	2	7
Tanner JP et al.	4	1	2	7