Table 2.
General information of enrolled RCTs (according to the Cochrane Collaboration's tool for assessing risk of bias)
| Sequence generation | Allocation concealment | Blinding of participants, personnel and assessors | Incomplete outcome data | Selective outcome reporting | Other sources of bias | |
|---|---|---|---|---|---|---|
| Liu 2001 (22) | Random table | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Ding 2006 (23) | Random table | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Hu 2008 (24) | Computer random number generator | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Yang 2008 (25) | Coin tossing | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Chen 2008 (26) | Computer random number generator | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Zhou 2009 (27) | Unclear † | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Wu 2010 (28) | Computer random number generator | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
| Lei 2011 (29) | Unclear † | Unclear | Measurement not influenced by lack of blinding | No missing outcome data | All pre‐specified outcomes reported | No |
†High risk.