Table 4.

Overall quality judgment of each study assessed by the ROBINS-I tool.

Author	Overall Risk of Bias Judgment*	Main Sources of Bias
Arquer et al. [44]	Serious	No control group High drop-out rate Limited participant information
Baar [45]	Serious	One participant
Farup et al. [42]	Low	Small study population
Hjerrild et al. [31]	Serious	Cross-sectional design Incomprehensive exposure assessment Not all confounders were taken into account
Jain, et al. [29]	Moderate/Serious	Small study population Participant-reported outcome Incomplete follow-up
Owens et al. [30]	Moderate	Not all confounders were taken into account Only severe cases were identified Inappropriate statistical adjustments
Passaretti et al. [33]	Serious	Potential of selection bias Potential for underreporting of alcohol consumption
Rechardt et al. [32]	Moderate	Cross-sectional design Data of association not shown
Schneider et al. [46]	Critical	Small study population Selection bias No quantification and qualification of exposure Single participant-reported outcome measure
Vitali et al [43].	Moderate	No placebo Mainly participant-reported outcomes

*Possible judgments are: Low, Moderate, Serious, Critical