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 |
|---|---|---|---|---|---|---|---|---|
Clollinge (1998) [10] | Low | Low | High | Low | Low | High | High | Unclear |
Dybwad (2007) [11] | Low | Low | High | Low | Low | Unclear | Low | Low |
Surawy (2005) [12] | Unclear | Unclear | High | Unclear | High | Unclear | Unclear | Unclear |
Walach (2008) [13] | Low | Low | Low | Low | Low | High | Low | Low |
Field (1997) [14] | Low | Unclear | High | High | Unclear | Unclear | Unclear | High |
Wang (2009) [15] | Unclear | Unclear | Low | Low | High | Unclear | Low | Unclear |
Liu (2010) [16] | Unclear | Unclear | High | Unclear | Unclear | Unclear | Unclear | Unclear |
Weatherley-Jones (2004) [17] | Low | Low | Low | Low | Low | Low | Low | Low |
Awdry (1996) [18] | Unclear | Unclear | Low | Low | High | High | Low | Unclear |
Hartz (2004) [19] | Low | Low | Low | Low | Low | Low | Low | Low |
Forsyth (1999) [20] | Unclear | Unclear | Low | Unclear | Unclear | High | Unclear | Unclear |
Santaella (2004) [21] | Unclear | Unclear | High | High | High | High | Low | Unclear |
Brouwers (2002) [22] | Unclear | High | Low | Low | Low | Low | Unclear | Low |
De Becker (2001) [23] | Unclear | Low | Low | Unclear | Unclear | Unclear | Unclear | Low |
The (2007) [24] | Low | Low | Low | Low | Low | Low | Unclear | Low |
McDertmott (2006) [25] | Low | Low | Low | Low | Low | High | Low | Low |
Stewart (1987) [26] | Unclear | Unclear | High | High | Low | High | High | Unclear |
Rothschild (2002) [27] | Unclear | Unclear | Low | Low | High | High | Unclear | Unclear |
Vermeulen (2004) [28] | Low | Low | Low | Low | Low | Low | Low | Low |
Behan (1990) [29] | Low | Low | High | High | Low | Unclear | High | Unclear |
Warren (1999) [30] | Low | Low | Low | Low | Low | Low | Low | Unclear |
Kaslow (1989) [31] | Unclear | Low | Low | Low | Low | Unclear | Unclear | Low |
Ockerman (2000) [32] | Unclear | Low | Low | Low | Low | Unclear | Unclear | Low |
Cox (1991) [33] | Unclear | Unclear | Low | Low | Unclear | High | Low | Unclear |
Tiev (1999) [34] | Unclear | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Unclear |
Willams (2002) [35] | Unclear | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Unclear |