Table 3.

The risk of bias in non-randomized studies of interventions (ROBINS-I) assessment tool

Authors, year	Risk of bias within each domain							Overall risk of bias across domains	Overall risk of bias across studies
	Confounding	Participant selection	Intervention classification	Departure from intended interventions	Missing data	Measurement of outcomes	Selection of reported results
Barbosa et al, 201328	Critical	Critical	Serious	Moderate	Moderate	Critical	Moderate	Critical	High
Lee et al, 201431	Critical	Serious	Serious	Moderate	Moderate	Serious	Moderate	Critical

Judgement (within a study): Low risk of bias (comparable to a well performed randomized controlled trial: RCT), Moderate risk of bias (sound, but not comparable to a well performed RCT), Serious risk of bias (important problems), Critical risk of bias (too problematic to provide useful evidence), No information.

(Across studies) Low risk of bias: Most information is from studies at low risk of bias

Unclear risk of bias: Most information is from studies at low or unclear risk of bias

High risk of bias: The proportion of information from studies at high risk of bias is sufficient to affect the interpretation of results