Table 2.

Risk of bias and quality assessment.

Author	Case/ Representative	Representative/Nonexposed	Controls/Exposure	Definition/Outcome not present	Confounding	Exposure/Outcome	Method/Follow-up	Nonresponse/Adequate follow-up	Score
Puzzono 2022 (22)	*	*	*	*	–	*	*	*	7
Nguyen 2022 (23)	–	*	–	*	**	*	*	*	7
McDowell 2022 (24)	*	*	*	*	*	*	*	*	8
Li 2022 (25)	–	*	*	*	**	*	*	*	8
Jin 2022 (26)	*	*	*	*	**	*	*	*	9
Pang 2022 (27)	*	*	*	*	**	*	–	–	7
Danial 2022 (28)	*	*	*	*	–	–	*	*	6
Archambault 2021 (29)	*	*	*	*	*	*	*	*	8
Kim 2021 (30)	–	*	–	*	**	–	*	*	6
Zheng 2021 (31)	–	*	*	*	**	*	*	*	8
Yue 2021 (32)	–	*	*	*	**	*	*	*	8
Schumacher 2021 (33)	*	*	*	*	**	*	*	*	9
Nguyen 2021 (34)	–	*	*	*	**	*	*	*	8
Joh 2021 (35)	–	*	*	*	**	*	*	*	8
Chen 2021 (36)	*	*	*	*	**	*	*	*	9
Hur 2021 (37)	–	*	*	*	**	*	*	*	8
Chang 2021 (38)	–	*	*	*	**	*	–	*	7
Demb 2020 (39)	–	*	*	*	**	*	*	*	8
Dash 2020 (40)	–	*	–	*	**	*	*	*	7
Low 2020 (13)	*	–	*	*	*	–	*	*	6
Gausman 2020 (41)	*	*	–	*	*	–	*	*	6
L'Heureux 2019 (42)	*	*	–	*	*	–	*	*	6
Liu 2019 (43)	–	*	–	*	**	*	*	*	7
Syed 2019 (44)	*	*	–	*	**	–	*	*	7
Glover 2019 (15)	*	*	*	*	**	–	*	*	8
Nguyen 2018 (45)	–	*	*	*	**	*	*	*	8
Levi 2017 (46)	*	*	*	*	–	*	*	*	7
Kwak 2016 (21)	*	*	*	*	*	–	–	*	6
Wu 2013 (47)	*	*	*	*	–	*	–	*	6
Søndergaard 2013 (48)	*	*	*	*	–	*	*	*	7
Rosato 2013 (49)	*	*	–	*	**	*	*	*	8
Ghadirian 1998 (50)	*	*	*	*	–	*	*	–	6
Negri 1998 (51)	*	*	*	*	–	–	*	*	6
Fuchs 1994 (52)	–	*	–	*	**	*	*	*	7
St John 1993 (53)	*	*	–	*	–	*	*	*	6
Peter 1989 (54)	*	*	*	*	–	*	*	*	7

The NOS is a quality scale that evaluates studies based on 3 broad categories: selection (maximum of four stars); comparability (maximum of two stars); and exposure/outcome (maximum of three stars). *, one point; **, two points; -, no points.