Table 3 Risk of bias
Lead author (year) | Country of conduct and year | Adequate sequence generation | Allocation concealment | Blinding outcome assessors | Blinding patients and providers | Incomplete outcome data addressed | Free of selective reporting | Funding source |
|---|---|---|---|---|---|---|---|---|
Leibovitz (1971) [24] | USA, 1970 | High | Unclear | Unclear | Unclear | Low | Unclear | Low |
Beutner (1979) [25] | USA, 1974 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Low |
Rytel (1977) [26] | USA, 1974 | Low | Low | Unclear | Unclear | Low | Unclear | Unclear |
Monto (1982) [27] | USA, 1979 | Unclear | Unclear | Unclear | Unclear | Low | Unclear | Low |
Tannock (1984) [28] | Australia, 1981 | High | Unclear | Unclear | Low | Low | Unclear | Unclear |
Keitel (1997) [29] | USA, 1983 to 1988 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Low |
Gruber (1990) [30] | USA, 1985 | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Low |
Edwards (1994) [31] | USA, 1986 to 1990 | Low | Low | Unclear | Low | Unclear | Unclear | Low |
Clover (1991) [32] | USA, 1989 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Low |
Govaert (1994) [33] | The Netherlands, 1991 | Unclear | Low | Unclear | Low | Low | Unclear | Low |
Powers (1995) [34] | USA, 1993 | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Low |
Belshe (1998) [35] | USA, 1996 | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Low |
Rudenko (2001) [36] | Russia, 1996 | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear | Unclear |
Belshe (2000) [37] | USA, 1997 | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Low |
Bridges (2000) [38] | USA, 1997 to 1998 | Unclear | Unclear | Unclear | Low | Low | Unclear | Low |
Hoberman (2003) [39] | USA, 1999 to 2000 | Low | Unclear | Low | High | Low | Unclear | Unclear |
Tam (2007) [40] | Multisite trial in Asia, 2000 to 2001 | Low | Low | Unclear | Low | Unclear | Unclear | Unclear |
Vesikari (2006) [41] | Multisite trial in Europe and Israel, 2000 to 2001 | Unclear | Unclear | Unclear | Low | Low | Unclear | Unclear |
Bracco Neto (2009)a[10] | Multisite trial in South Africa and South America, 2001 to 2002 | Low | Low | Low | Unclear | Unclear | Unclear | Unclear |
Lum (2010) [43] | Multisite trial in Asia, Europe and South America, 2002 | Unclear | Low | Low | Low | Low | Unclear | Unclear |
Forrest (2008) [42] | Multisite in Asia, 2002 | Unclear | Unclear | Unclear | Low | Unclear | Unclear | Unclear |
Langley (2011) [44] | Canada, 2003 | Unclear | Unclear | Low | Low | Low | Unclear | Unclear |
Ohmit (2006)a[11] | USA, 2004 | Unclear | Unclear | Unclear | Low | Low | Low | Low |
Treanor (2007)a[12] | USA, 2004 | Unclear | Unclear | Unclear | Low | Low | Low | Unclear |
Beran (2009) [45] | Czech Republic, 2005 | Low | Low | Unclear | Low | Low | High | Unclear |
Jackson (2010) [15] | USA, 2005 | Low | Low | Unclear | Unclear | Low | Low | Unclear |
Ohmit (2008)a[13] | USA, 2005 | Unclear | Unclear | Unclear | Low | Low | Low | Low |
Beran (2009) [46] | Multisite trial Europe, 2006 | Unclear | Unclear | Unclear | Low | Low | High | Unclear |
Monto (2009)a[14] | USA, 2007 | Unclear | Unclear | Unclear | Low | Low | Low | Unclear |
Frey (2010) [47] | Multisite trial North America and Europe, 2007 | Unclear | Unclear | Unclear | Unclear | Low | Low | Unclear |
Treanor (2011) [48] | USA, 2007 | Unclear | Unclear | Unclear | Unclear | Low | Low | Unclear |
Barrett (2011) [49] | Multisite trial in USA, 2008 | Low | Low | Unclear | Low | Unclear | Unclear | Unclear |
Cowling (2010) [50] | Hong Kong, 2008 | Low | Low | Unclear | Low | Low | Low | Low |
Talaat (2010) [51] | USA, 2009 | Unclear | Unclear | Unclear | Low | Low | Unclear | Unclear |