Table 2 Risk of bias in included studies
Study | Random Sequence Generation | Allocation concealment | Blinding of participants | Blinding of outcome assessment | Incomplete Outcome data | Selective reporting | Other bias |
|---|---|---|---|---|---|---|---|
Kim 2007 | Yes (Randomization table) | Unclear | Unclear | Yes | Yes | Unclear | Unclear |
Shen 2007 | Yes (Not reported) | Unclear | Unclear | Unclear | Yes | Unclear | Unclear |
Karpman 2009 | Yes (Computer) | Unclear | Yes | Yes | Yes | Unclear | Unclear |
Lin 2009 | Yes (Computer) | Yes (Sealed envelope) | Yes | Yes | Yes | Unclear | Unclear |
Matsumoto 2011 | Yes (Not reported) | Unclear | Yes | Unclear | Yes | Unclear | Unclear |
Chiang 2012 | Yes (computer) | Unclear | Yes | Yes | Yes | Yes | Unclear |
Lin 2013 | Yes (Randomization table) | Yes (Sealed envelope) | Unclear | Yes | Yes | Unclear | Unclear |
Tasker 2013 | Yes (Randomization table) | Yes (Sealed envelope) | Yes | Yes | Yes | Unclear | Unclear |
Xu 2013 | Yes (Randomization table) | Yes (Sealed envelope) | Unclear | Unclear | Yes | Unclear | Unclear |
Roysam 2001 | Yes (Random number table) | Yes (Sealed envelope) | Yes | Yes | Yes | Unclear | Unclear |
Weinhardt 2004 | Yes (Not reported) | Unclear | Unclear | Unclear | Yes | Unclear | Unclear |
Bridgman 2009 | Yes (Computer) | Yes (Telephone) | Yes | Yes | Yes | YES | Unclear |
Sastre 2009 | Yes (Random number table) | Yes (Sealed envelope) | Yes | Yes | No | Unclear | Unclear |
Pan 2010 | Yes (Computer) | Yes (Sealed envelope) | Yes | No | Yes | Unclear | Unclear |
Varela-Egocheaga 2010 | Yes (Random number table) | Unclear | Unclear | Unclear | Yes | Unclear | Unclear |
Van Hemert 2010 | Yes (Not reported) | Unclear | Yes | Yes | Yes | Unclear | Unclear |
Bourke 2012 | Yes (Computer) | Yes (Sealed envelope) | Yes | Yes | No | Unclear | Unclear |
Wegrzyn 2013 | Yes (Computer) | Unclear | Yes | Yes | Yes | Unclear | Unclear |
Jain 2013 | Yes (Computer) | Yes (Block schedule) | Yes | Unclear | Yes | Unclear | Unclear |