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

aUnpublished data was obtained from the author(s).

Tricco et al.

Tricco et al. BMC Medicine 2013 11:153   doi:10.1186/1741-7015-11-153

Open Data