Table 6.

ROBINS-I risk of bias for all studies.

Study	Bias due to confounding	Bias in selection of participants into the study	Bias in classification of interventions	Bias due to deviations from intended interventions	Bias due to missing data	Bias in measurement of outcomes	Bias in selection of the reported result	Overall bias
Brereton et al. (53)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Chen et al. (65)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Chen et al. (60)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Cordaro et al. (58)	NI	Low	Low	Low	Moderate	Serious	Moderate	Serious
Dong et al. (64)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Gall and Riely (59)	Critical	Low	Low	Low	Low	Moderate	Moderate	Critical
Garret-Bakelman et al. (25)	Moderate	Low	Low	Moderate	Low	Low	Moderate	Moderate
Hao et al. (54)	Low	Moderate	Low	Low	Low	Low	Moderate	Moderate
Jin et al. (62)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Li et al. (46)	Low	Serious	Low	Low	Low	Low	Moderate	Serious
Liu et al. (40)	Low	Low	Low	Low	Low	Low	Low	Low
Lizko et al. (61)	Low	Low	Low	Low	Serious	Moderate	Moderate	Serious
Mardanov et al. (44)	Serious	Low	Serious	Moderate	Low	Moderate	Moderate	Serious
Meng et al. (55)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Turroni et al. (52)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
shilov et al. (57)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Rerberg et al. (56)	NI	NI	Low	Low	Low	Low	Moderate	Moderate
Voorhies et al. (37)	Low	Low	Low	Low	Low	Low	Moderate	Moderate
Zhang et al. (63)	Low	Low	Low	Low	Low	Low	Moderate	Moderate

A risk of bias is classified as “Low risk” (green coloured), “Moderate risk” (yellow coloured), “Serious risk” (orange coloured), or “Critical risk” of bias (red coloured). Some risks of bias could not be assessed due to lack of information and are therefore marked with “No information (NI)” (grey coloured).