Table 2

Risk of bias within included studies

Author, year, locationClinical interaction?GroupDoes the study provide estimates of the random variability in the data for the main outcomes?Have the characteristics of the patients included and excluded been described?Were study subjects in different intervention groups recruited over the same period of time?Were incomplete questionnaires excluded?Reviewer scoresRisk of bias adjudication
Fischer et al, 2007, New Jersey, USA23YesSurgery/procedural111014 of 27Low
Hartmans et al, 2014, Leuven, Belgium40NoOutpatient101114 of 27Low
Gooden et al, 2001, Sydney, Australia27NoMixed011013 of 27Low
Baevsky et al, 1998, Massachusetts, USA17YesAcute care011012 of 27Low
Gherardi et al 2009, West Yorkshire, England26NoMixed111112 of 27Low
Lill and Wilkinson, 2005, Christchurch, New Zealand32NoMixed111012 of 27Low
Niederhauser et al, 2009, Virginia, USA36NoSurgery/procedural011012 of 27Low
Rehman et al, 2005, South Carolina, USA1NoMedicine011012 of 27Low
Pronchik et al, 1998, Pennsylvania, USA37YesAcute care011011.5 of 27Moderate
Au et al, 2013, Alberta, Canada16NoAcute care011011.5 of 27Moderate
Li and Haber 2005, New York, USA31YesAcute care111011.5 of 27Moderate
Al-Ghobain et al, 2012, Riyadh, Saudi Arabia15NoMedicine011011 of 27Moderate
Boon et al, 1994, Sheffield, England18YesAcute care011011 of 27Moderate
Chung et al, 2012, Kyunggido, Republic of Korea5YesMedicine110011 of 27Moderate
Edwards et al, 2012, Texas, USA22YesSurgery/procedural011111 of 27Moderate
Kersnik et al, 2005, Krajnska Gora, Slovenia29YesMedicine000111 of 27Moderate
Yonekura et al, 2013, Sao Paulo, Brazil42NoMixed011111 of 27Moderate
Maruani et al, 2013, Tours, France33NoSurgery/procedural011010.5 of 27Moderate
Cha et al, 2004, Ohio, USA20NoSurgery/procedural001010.5 of 27Moderate
Chang et al, 2011, Seoul, Republic of Korea21NoMedicine000010.5 of 27Moderate
Budny et al, 2006, Iowa and NY, USA19NoSurgery/procedural011010 of 27Moderate
Ikusaka et al, 1999, Tokyo, Japan28YesMedicine011010 of 27Moderate
McLean et al, 2005, Surrey, England39YesSurgery/procedural001110 of 27Moderate
Kurihara et al, 2014, Ibaraki, Niigata and Tokyo, Japan41NoOutpatient011110 of 27Moderate
Friis and Tilles, 1988, California, USA24YesMixed01009.5 of 27High
Sotgiu et al, 2012, Sassari, Italy38NoMixed00109.5 of 27High
Gallagher et al, 2008, Dublin, Ireland25NoMedicine01109 of 27High
Kocks et al, 2010, Groningen, Netherlands30NoMedicine00018 of 27High
McNaughton-Filion et al, 1991, Ontario, Canada35NoMedicine00007.5 of 27High
McKinstry and Wang, 1991, West Lothian and Edinburgh, Scotland34NoMedicine00007 of 27High
  • A priori, studies that received a score of 12 or greater were considered to be at low risk of bias; scores of 10–12 moderate risk of bias; and scores less than 10 at high risk of bias.

  • Scores for key questions that differentiated studies at high versus moderate and low risk of bias are shown.

  • Scores shown represent independently rated and agreed-on ratings by two reviewers.