Table 2.
Risk of bias of included RCTs*.
| Study | Random sequence generation | Allocation concealment | Patient blinding | Assessor blinding | Reporting drop-out or withdrawal† | Intention-to-treat analysis† | Selective outcome reporting | Other potential bias |
|---|---|---|---|---|---|---|---|---|
| Wang et al. 2010 [7] | Low | Low | Low | Low | Low | Low | Low | Low |
| Hsiao et al. 2003 [8] | Unclear | Low | Low | Low | Low | High | Low | Unclear |
| Özsoy and Ernst 1999 [9] | Low | Low | Low | Low | Low | High | Low | Low |
| Liu et al. 2005 [10] | Low | Low | Low | Low | Low | High | Low | Low |
| Bishop et al. 2007 [11] | Low | Low | Low | Low | Low | Low | Low | Low |
| Tsao et al. 2005 [12] | Low | Low | Low | Low | Low | High | Low | Low |
| Higgins et al. 2011 [24] | Unclear | Low | Low | Low | Low | Low | Low | Unclear |
| Burack et al. 1996 [13] | Low | High | High | High | Low | Low | Low | Unclear |
| Sangkitporn et al. 2005 [14] | Low | Low | Low | Low | Low | Low | Low | Low |
| Shi and Peng 2003 [15] | Low | Low | Low | High | Low | Low | Low | Unclear |
| Wang et al. 2006 [16] | Low | Low | Low | Low | Low | Low | Low | Low |
*Domains of quality assessment based on Cochrane tools for assessing risk of bias.
†Two domains referring to “incomplete outcome data” in the Cochrane tools for assessing risk of bias.
Abbreviations: low: low risk of bias; high: high risk of bias; unclear: uncertain risk of bias.