Table 2.
No. of studies low/unclear/high risk | |||
---|---|---|---|
Criteria | RCT (n = 17) | NRT (n = 12) | UBA (n = 50) |
Random sequence generation | 6/11/0 | N/Aa | N/Aa |
Allocation concealment | 11/6/0 | 9/3/0 | N/Aa |
Similarity of baseline outcomes | 13/4/0 | 8/4/0 | N/Aa |
Similarity of baseline characteristics | 10/6/1 | 8/4/0 | N/Aa |
Blinding of participants and personnel | 6/11/0 | 4/8/0 | N/Aa |
Blinding of outcome assessment: | |||
Knowledge | 13/4/0 | 8/4/0 | N/Aa |
Other outcomes | 8/9/0 | 4/8/0 | N/Aa |
Blinding of participants to the research question/purpose | N/Aa | N/Aa | 16/30/4 |
Independence of intervention effect from confounding bias | 15/2/0 | 11/1/0 | 48/1/1 |
Valid/reliable outcome measurement | 14/3/0 | 10/2/0 | 33/17/0 |
Incomplete outcome data: | |||
Knowledge | 12/2/3 | 8/3/1 | 31/19/0 |
Other outcomes | 12/2/3 | 8/3/1 | 30/20/0 |
Selective reporting | 15/0/2 | 9/2/1 | 40/9/1 |
Other | 14/3/0 | 12/0/0 | 48/2/0 |
Overall risk-of-bias: | |||
Knowledge | 8/6/3 | 7/4/1 | 34/15/1 |
Other outcomes | 8/6/3 | 7/4/1 | 33/16/1 |
RCT randomized controlled trials, NRT non-randomized controlled trials, UBA uncontrolled before-and-after studies
aN/A = These criteria not assessed for these study designs