Table 1 Risk of bias summary for non-randomised studies
Study | Confounding | Participant selection | Classification of intervention | Deviations from intended Interventions | Incomplete outcome data | Measurement of outcomes | Selective reporting | Overall |
|---|---|---|---|---|---|---|---|---|
Fukutomi 2005 [18] | 3 | 1 | 3 | 1 | 0 | 1 | 1 | 3 |
Taketani 2008 [22] | 3 | 1 | 3 | 1 | 0 | 1 | 1 | 3 |
Tsuji 2011 [28] | 3 | 1 | 1 | 1 | 0 | 1 | 1 | 3 |
Toriumi 2012 [30] | 2 | 1 | 3 | 1 | 3 | 1 | 1 | 3 |
Kawamura 2007 [19] | 3 | 1 | 3 | 1 | 2 | 1 | 1 | 3 |
Kawamura 2008 [21] | 3 | 1 | 3 | 1 | 0 | 1 | 1 | 3 |
Kawamura 2009 [23] | 3 | 1 | 3 | 1 | 0 | 1 | 1 | 3 |
Mori 2010 [24] | 3 | 1 | 3 | 3 | 0 | 1 | 3 | 3 |
Nabeshima 2010 [25] | 2 | 1 | 1 | 1 | 3 | 1 | 1 | 3 |
Suzuki 2011 [27] | 2 | 1 | 1 | 1 | 2 | 1 | 1 | 2 |