Cross-sectional – Newcastle-Ottawa Scale.

Author		Achua et al. (2021) (19)	Alkhatatbeh et al. (2020) (21)	Chen et al. (2021) (28)	Ediz et al. (2021) (31)	Gacci et al. (2021) (35)	Kayaaslan et al. (2020) (41)	Lamb et al. (2020) (46)	Li et al. (2020) (47)
Selection
	1	0	1	1	1	1	1	0	0
	2	1	0	0	0	0	0	0	0
	3	1	1	1	1	1	1	0	1
Confounder
	1	0	0	0	0	0	0	0	0
Outcome
	1	1	1	1	0	1	1	1	1
Total		3	3	3	2	3	3	1	2

		Li et al. (2020) (48)	Machado et al. (2021) (50)	Pan et al. (2020) (55)	Rastrelli et al. (2021) (58)	Rawlings et al. (2020) (59)	Ruan et al. (2020) (61)	Temiz et al. (2021) (64)	Xu et al. (2021) (65)
Selection
	1	1	1	1	1	0	1	1	1
	2	0	0	0	1	0	0	1	1
	3	1	1	1	1	1	1	1	1
Confounder
	1	0	0	0	0	0	0	2	1
Outcome
	1	1	1	1	1	1	1	1	1
Total		3	3	3	4	2	3	6	5