Study | Parallelism of groups | Comparability of groups | Blinding | Selective reporting improbable | Absence of other factors potentially causing bias | Risk of bias: study level | Risk of bias: outcome level | |
---|---|---|---|---|---|---|---|---|
Patients | Treating staff | |||||||
Yes | Yes | No | No | Unclear | Noa | High | High | |
Myrseth 2009 [20] | Yes | Nob | No | No | Unclear | Yes | High | High |
Pollock 2006 [21] | Yes | Noc | No | No | Unclear | Yes | High | High |