Table 3 Risk of bias assessments from individual trials extracted from published Cochrane reviews
Author name, year, study design, country | Random sequence generation | Allocation concealment | Protection against contamination | Baseline outcomes similar | Baseline characteristics similar | Blinding of outcome assessment | Incomplete outcome data | Selective reporting | Other bias |
|---|---|---|---|---|---|---|---|---|---|
Baer 2016, cluster RCT, USA | Low risk | Unclear risk | Low risk | Not assessed | Not assessed | High risk | High risk | High risk | Unclear risk |
Barnett 1983, RCT, USA | Unclear risk | Unclear risk | High risk | Unclear risk | Low risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Burack 1996, RCT, USA | Unclear risk | Unclear risk | High risk | Unclear risk | Low risk | Low risk | Low risk | Unclear risk | Unclear risk |
Chambers 1989, RCT, USA | Low risk | Unclear risk | High risk | Low risk | Low risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk |
Chambers 1991, cluster RCT, USA | Low risk | Unclear risk | Low risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk |
Cranney 2008, cluster RCT, Canada | Low risk | Low risk | Unclear risk | Low risk | Low risk | Unclear risk | Low risk | Unclear risk | Low risk |
Daucourt 2003, cluster RCT, France | Low risk | Low risk | Not assessed | Unclear risk | Unclear risk | Unclear risk | Low risk | Low risk | Low risk |
Dey, 2004, cluster RCT, England | Low risk | Low risk | Unclear risk | Unclear risk | Low risk | High risk | Low risk | Unclear risk | Low risk |
Eccles, 2001, RCT, England | Low risk | Low risk | Low risk | High risk | Unclear risk | Low risk | Low risk | Unclear risk | Unclear risk |
Engers, 2005, cluster RCT, Denmark | Low risk | High risk | Unclear risk | Unclear risk | Unclear risk | High risk | Low risk | Unclear risk | High risk |
Feldstein 2006, RCT, USA | Low risk | Low risk | Unclear risk | Unclear risk | Low risk | Low risk | Low risk | Unclear risk | Unclear risk |
Fisher 2013, RCT, Singapore | Low risk | Low risk | Unclear risk | Low risk | High risk | High risk | Low risk | Low risk | Low risk |
Goodfellow 2016, cluster RCT, England | Low risk | Low risk | Low risk | Low risk | Unclear risk | Low risk | Unclear risk | Low risk | Not assessed |
Grant 2011, RCT, USA | Unclear risk | Low risk | Low risk | Low risk | High risk | Low risk | Low risk | Low risk | Low risk |
Ince 2015, RCT, England | Low risk | Low risk | Not assessed | Not assessed | Not assessed | Low risk | Unclear risk | Low risk | Low risk |
King 2016, RCT, USA | Low risk | Low risk | Unclear risk | Low risk | Low risk | High risk | Low risk | Low risk | Unclear risk |
Lafata 2007, cluster RCT, USA | High risk | Unclear risk | Unclear risk | Low risk | Unclear risk | High risk | High risk | Unclear risk | Low risk |
Le Breton, 2016, cluster RCT, France | Low risk | Low risk | Low risk | Low risk | High risk | Low risk | Low risk | Low risk | Unclear risk |
Leslie 2012; RCT; Canada | Low risk | Low risk | Unclear risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
Lobach, 1997, RCT, USA | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Unclear risk | Unclear risk |
Majumdar 2007, RCT, Canada | Low risk | Low risk | High risk | Unclear risk | Unclear risk | Low risk | Low risk | Unclear risk | Low risk |
Majumdar 2008, RCT, Canada | Low risk | Low risk | High risk | Unclear risk | Unclear risk | Low risk | Low risk | Unclear risk | Low risk |
Martin Madrazo 2012, cluster RCT, Spain | Low risk | Low risk | Low risk | Low risk | High risk | Low risk | Low risk | Low risk | High risk |
McAlister, 2006, RCT, Canada | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk | Low risk |
Mertz 2010, cluster RCT, Canada | Low risk | Low risk | High risk | Low risk | High risk | Unclear risk | Low risk | Low risk | High risk |
Munoz-Price 2014, cross-over RCT, USA | Low risk | Low risk | High risk | Unclear risk | Low risk | High risk | Low risk | Low risk | Low risk |
Rahme 2005, cluster RCT, Canada | Unclear risk | Unclear risk | Low risk | Unclear risk | Low risk | Low risk | Low risk | Unclear risk | Unclear risk |
Robling 2002, cluster RCT, England | High risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk | Unclear risk |
Rodriguez 2015, cluster RCT, Argentina | Low risk | Unclear risk | Unclear risk | Low risk | Unclear risk | Unclear risk | Low risk | Low risk | Low risk |
Rogers 1982, RCT, USA | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Unclear risk | Low risk | High risk | High risk | Not assessed |
Rossi 1997, cluster RCT, USA | Low risk | Low risk | Low risk | Unclear risk | High risk | Low risk | Unclear risk | Unclear risk | Unclear risk |
Roux, 2013, RCT, Canada | Low risk | Low risk | Unclear risk | Low risk | High risk | High risk | Low risk | Unclear risk | Unclear risk |
Schnoor 2010, RCT, Germany | Low risk | Low risk | Low risk | High risk | High risk | Unclear risk | Unclear risk | Unclear risk | High risk |
Schouten 2007, cluster RCT, Netherlands | Low risk | Low risk | Low risk | Low risk | Low risk | Unclear risk | Low risk | Unclear risk | Low risk |
Shah 2014, cluster RCT, Canada | Low risk | Low risk | Not assessed | Low risk | High risk | Low risk | Low risk | Unclear risk | Unclear risk |
Shojania 1998, RCT, USA | Unclear risk | High risk | High risk | Unclear risk | Low risk | High risk | Unclear risk | Low risk | Low risk |
Solomon 2007, cluster RCT, USA | Low risk | Unclear risk | Low risk | Unclear risk | Low risk | Low risk | Low risk | Low risk | Unclear risk |
Solomon 2001, RCT, USA | Low risk | Unclear risk | Low risk | Unclear risk | Low risk | Low risk | Low risk | Low risk | Unclear risk |
Stewardson 2016, cluster RCT, Switzerland | Low risk | Low risk | Unclear risk | Low risk | Unclear risk | High risk | Low risk | Low risk | Low risk |
Taveras 2015, cluster RCT, USA | Low risk | Low risk | Low risk | Low risk | Unclear risk | Low risk | Low risk | High risk | Not assessed |
Thompson 2008, cluster RCT, England | Low risk | Low risk | Not assessed | Not assessed | Not assessed | Unclear risk | Low risk | Low risk | Unclear risk |
Yeung 2011, cluster RCT, Hong Kong | Unclear risk | Low risk | Unclear risk | Low risk | High risk | High risk | Low risk | Low risk | High risk |