Table 2.

Risk of bias for non-randomized studies assessed with ROBINS-I Cochrane tool

Risk of Bias domains included in ROBINS-I Cochrane tool.	Category of BIAS	Poisson et al.	Gerritsen et al.	Chen et al.	Nakayama et al.	Murray et al.
Pre-intervention domains
1.Bias due to confounding.	Confounding	3	2	1	2	3
2. Bias in selection of participants into the study.	Selection Bias	3	1	1	2	2
At-intervention domain
3. Bias in classification of interventions.	Information bias	1	1	1	1	2
Post-intervention domains
4. Risk of bias due to deviations from the intended interventions (effect of assignment to intervention)	Confounding	2	2	1	1	1
5. Bias due to missing data	Selection Bias	2	2	1	1	1
6. Bias in measurement of the outcome	Information bias	1	1	1	1	1
7. Bias in selection of the reported result	Reporting bias	2	1	1	1	1
Overall Risk of BIAS for the results		3	2	1	2	3