Table 3. Cochrane risk of bias assessment.
| Sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data | Selective outcome reporting | Other potential threats | |
| Calo 2005 | YES | UNCLEAR | NO | NO | YES | YES | YES |
| Heidt 2009 | UNCLEAR | UNCLEAR | YES | UNCLEAR | YES | YES | YES |
| Saravanan 2010 | YES | UNCLEAR | YES | UNCLEAR | YES | YES | YES |
| Heidarsdottir 2010 | UNCLEAR | UNCLEAR | YES | UNCLEAR | YES | YES | YES |
| Farquharson 2011 | YES | YES | YES | YES | YES | YES | YES |
| Sorice 2011a 1 | UNCLEAR | UNCLEAR | NO | NO | YES | YES | YES |
| Sorice 2011b 1 | UNCLEAR | UNCLEAR | NO | NO | YES | YES | YES |
| Sandesara 2012 | UNCLEAR | UNCLEAR | YES | YES | YES | YES | YES |
| Mozaffarian 2012 | YES | YES | YES | YES | YES | YES | YES |
1
The study by Sorice et al includes two randomized comparisons in patients who underwent off-pump or on-pump surgery. These two sets of data were analyzed separately in the meta-analysis, as Sorice 2011a and Sorice 2011b.
YES, low risk of bias; UNCLEAR, uncertain risk of bias; NO, high risk of bias.