Table 4.
Summary of risk of bias assessment
| Study | Adequate sequence generation | Allocation concealment | Outcome blinding | Incomplete outcome data addressed | Intention to treat analysis |
|---|---|---|---|---|---|
| Arthur (2002)36 | Unclear | Yes | Yes | Yes (dropout rate: 8% and 10% at 6 and 18 months, respectively) | Yes |
| Bell (1998)30 | Unclear | Yes | Yes | Unclear | No |
| Carlson (2000)32 | Unclear | Unclear | Unclear | No | Yes |
| Dalal (2007)21 | Yes | Yes | Yes | Yes | Yes |
| Daskapan (2007)34 | Unclear | Unclear | Unclear | Yes | No |
| Gordon (2002)26 | Unclear | Unclear | Unclear | Yes | Unclear |
| Jolly (2007)22 | Yes | Yes | Yes | Yes | Yes |
| Kassaian (2000)25 | Unclear | Unclear | Unclear | Unclear | Unclear |
| Marchionni (2003)24 | Unclear | Unclear | Yes | Yes | Yes |
| Miller (1984)27 | Unclear | Unclear | Unclear | Yes | Yes |
| Sparks (1993)37 | Unclear | Unclear | Unclear | Yes | Yes |
| Wu (2006)35 | Unclear | Unclear | Yes | Unclear | Unclear |