Table 2.

Risk of bias assessment.

Author	Country	Domains	Selection	Ascertainment (1) (2)		Casuality	Reporting
Fernandez Acenero et al.	Spain	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Schmidt-Westhausen et al.	Germany	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Dijkema et al.	Netherlands	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Leonhardt et al.	USA	Ascertained	Ascertained	Ascertained	Unclear	Not evaluable	Ascertained
Edwards et al.	USA	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Sanchis-Bielsa et al.	Spain	Ascertained	Unclear	Ascertained	Unclear	Not evaluable	Unclear
Dionyssopoulos et al.	Greece	Ascertained	Ascertained	Ascertained	Unclear	Not evaluable	Ascertained
Weyand et al.	Germany	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Unclear
da Costa Miguel et al.	Brazil	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Shahrabi Farahani et al.	USA	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Unclear
Lee et al.	Korea	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Unclear
Bulam et al.	Turkey	Ascertained	Ascertained	Ascertained	Unclear	Not evaluable	Ascertained
Curi et al.	Brazil	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Alghonaim et al.	Canada	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Paolino et al.	Italy	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Unclear
Ehsani et al.	Iran	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Kaczorowski et al.	Poland	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Wege et al.	UK	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained
Scarano et al.	Italy	Ascertained	Ascertained	Ascertained	Ascertained	Not evaluable	Ascertained