Study | Adequate sequence generation | Allocation concealment | Similar baseline outcome measures | Similar baseline characteristics | Incomplete outcome data addressed | Prevention knowledge allocated interventions | Adequate protection against contamination | Free of selective reporting | Free of other bias |
Campion, 1983, CCT11 | − | − | − | + | ? | ? | − | ? | − |
Collard, 1985, RCT12 | ? | ? | + | − | − | ? | − | − | − |
Becker*, 1987, RCT13 | + | + | + | + | ? | + | − | + | − |
Saltz*, 1988, RCT14 | + | + | ? | ? | ? | + | − | + | − |
McVey*, 1989, RCT15 | + | + | + | + | + | + | − | + | − |
Gayton, 1987, CCT16 | − | − | + | + | ? | + | − | − | + |
Hogan, 1987, RCT17 | + | ? | + | + | ? | + | − | − | + |
Fretwell, 1990, RCT18 | ? | ? | + | + | ? | ? | + | ? | + |
Hogan, 1990, CCT19 | − | ? | ? | ? | ? | − | − | − | + |
Inouye, 1993, CCT20 | − | + | + | − | + | + | ? | + | + |
Thomas, 1993, RCT21 | + | + | + | + | ? | ? | − | ? | + |
Winograd, 1993, RCT22 | + | + | + | + | + | + | − | − | + |
Clark, 1995, CCT23 | − | − | − | − | ? | − | ? | − | − |
Landefeld, 1995, RCT24 | + | + | − | + | ? | − | − | ? | + |
Reuben, 1995, RCT25 | + | ? | + | + | ? | ? | − | + | + |
Asplund, 2000, RCT26 | + | + | + | + | ? | − | − | ? | − |
Counsell, 2000, RCT27 | + | + | + | − | + | − | − | + | + |
Cohen*, 2002, RCT28 | + | + | + | + | ? | + | − | + | + |
Phibbs*, 2006, RCT29 | + | + | + | + | ? | + | − | + | + |
Basic, 2005, RCT30 | + | + | + | − | + | + | ? | + | + |
+, yes; −, no; ?, unclear/not reported; CCT, controlled clinical trial; RCT, randomised controlled trial.
↵* Same study.