Table 2 Risk of Bias
Study | Selection Bias | Performance Bias | Detection Bias | Attrition Bias | Reporting Bias | Other | |
|---|---|---|---|---|---|---|---|
Random sequence generation | Allocation concealment | Blinding of participants and personnel | Blinding of outcome assessment | Incomplete outcome data addressed | Selective reporting | Other bias | |
Hallman 1986 | Unclear | Low | Low | Low | Low | Unclear | High |
Hallman 1992 | Unclear | Unclear | Low | Unclear | Low | Unclear | High |
Friedman 1995 | Unclear | Low | Unclear | Unclear | Low | Unclear | High |
Phelps 2013 | Low | Low | Low | Low | Low | Low | Low |
Phelps 2016 | Low | Low | Low | Low | Low | Low | Low |
Phelps 2018 | Low | Low | Low | Low | Low | Low | Low |