TABLE 2.
Risk of bias assessment of the included randomized controlled trials
| Study name (year) | Revised Cochrane risk‐of‐bias tool for randomized trials (RoB 2) | |||||
|---|---|---|---|---|---|---|
| Domain 1 | Domain 2 | Domain 3 | Domain 4 | Domain 5 | Overall risk‐of‐bias | |
| Matthews et al. (2003) [50] | SC | L | L | L | L | SC |
| Norholt et al. (2004) [14] | SC | L | L | L | L | SC |
| Cheung et al. (2004) [17] | SC | L | SC | SC | L | SC |
| Ueki et al. (2005) [19] | SC | L | L | L | L | SC |
| Cheung et al. (2008) [54] | SC | L | H | L | L | H |
| Park et al. (2010) [20] | SC | L | L | L | SC | SC |
| Stockmann et al. (2010) [13] | SC | L | L | L | L | SC |
| Tuovinen et al. (2010) [15] | SC | L | L | L | L | SC |
| Buijs et al. (2012) [55] | L | H | L | L | L | H |
| Yoshioka et al. (2012) [18] | SC | L | H | H | L | H |
| Bakelen et al. (2013) [56] | L | H | L | L | L | H |
| Yu et al. (2014) [16] | H | L | SC | L | SC | H |
| Bakelen et al. (2015) [57] | L | H | L | L | L | H |
| Gareb et al. (2017) [2] | L | H | L | L | L | H |
Domain 1, Bias arising from the randomization process; Domain 2, Bias due to deviations from the intended intervention; Domain 3, Bias due to missing outcome data; Domain 4, Bias in measurement of outcome; Domain 5, Bias in selection of reported results; H, high risk of bias; L, low risk of bias; SC, some concerns.