Studies | Randomization | Concealment of allocation | Double blinding | Withdrawal and dropout | Total score |
---|---|---|---|---|---|
Baker 2007 [13] | 1 | 2 | 2 | 1 | 6 |
Carlsson 2005 [14] | 2 | 2 | 1 | 1 | 6 |
Fernandez-Fairen 2013 [15] | 2 | 2 | 2 | 1 | 7 |
Fricka 2015 [16] | 2 | 2 | 1 | 1 | 6 |
Fricka 2019 [17] | 2 | 2 | 1 | 1 | 6 |
Gao 2009 [18] | 2 | 2 | 1 | 1 | 6 |
Khaw 2002 [19] | 1 | 2 | 2 | 1 | 6 |
Kim 2014 [2] | 2 | 2 | 2 | 1 | 7 |
McCaskie 1998 [20] | 1 | 2 | 1 | 1 | 5 |
Nam 2019 [21] | 2 | 2 | 2 | 1 | 7 |
Park 2011 [22] | 2 | 2 | 2 | 1 | 7 |