Study | Allocation concealment | Blinding | Intention to treat analysis | Predefined outcomes |
---|---|---|---|---|
Gates 1972 [13] | No | No | Unclear | No |
Small 1982 [14] | Unclear | Unclear | Unclear | No |
Bertrand 1992 [16] | Unclear | "Double-blind" | Yes | Yes |
Ring 1985 [15] | Unclear | "Single" | No | Unclear |
Lasser 1987 [17] | Yes | Yes | Unclear | Yes |
Lasser 1994 [18] | Yes | Yes | Yes | Yes |