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
|
- *, 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.
-
‡, This study had a baseline imbalance in the subjective outcome values.
- Abbreviations; Low (low risk of bias);/High (high risk of bias); Unclear (uncertain risk of bias).