|Study (Ref. #)||Prospective Design||Multicenter Enrollment||Selection Bias||Performance Bias||Attrition Bias||Detection Bias||Multivariate Adjustment for Potential Confounders|
|Brener et al. (18)||No||No||B||B||D||B||Probably adequate|
|Buszman et al. (16)||Yes||Yes||A||B||A||B||Probably adequate|
|Chieffo et al. (15)||No||No||A||B||A||B||Probably adequate|
|Makikallio et al. (19)||No||No||C||B||D||B||Probably adequate|
|Palmerini et al. (21)||Yes||No||A||B||A||B||Probably adequate|
|Sanmartin et al. (22)||No||No||A||B||A||B||Probably adequate|
|SYNTAX left main⁎ (20)||Yes||Yes||A||B||A||B||Probably adequate|
|Seung et al. (13)||Yes||Yes||A||B||A||B||Probably adequate|
|White et al.† (14)||No||No||A||B||A||B||Probably adequate|
|Wu et al. (17)||No||No||B||B||D||B||Probably adequate|
This was performed by 3 independent reviewers. The overall bias of the combined studies was considered moderate.
A = risk of bias is low; B = risk of bias is moderate; C = risk of bias is high; D = incomplete reporting.