Justification of choice of margin, total number of patient populations considered for analyses and patient population included in the analysis
| All articles (N=168) | Including NEJM protocols (N=61) | |
|---|---|---|
| n (%) | n (%) | |
| Justification of NI margin | ||
| Made no attempt for justification | 90 (54) | 22 (36) |
| Clinical basis. No evidence for consultation with external expert group, and no reference to previous trials of the control arm | 32 (19) | 11 (18) |
| Preservation of treatment effect based on estimates of control arm effect from previous trials | 13 (8) | 14 (23) |
| Expert group external to the authors. No reference to previous trials of the control arm | 6 (4) | 3 (5) |
| The same margin as was used in other similar trials | 5 (3 | 2 (3) |
| 10–12% recommended by disease-specific FDA guidelines | 4 (2) | 1 (2) |
| General comment that margin was decided according to FDA/regulatory guidance | 4 (2) | 0 |
| Clinical basis and based on previous similar trial. No evidence for consultation with external expert group, and no reference to previous trials of the control arm | 3 (2) | 0 |
| Based on registry/development programme | 0 | 2 (3) |
| Other* | 11 (7) | 6 (10) |
| Number of analyses | ||
| One | 65 (39) | 15 (25) |
| Two | 91 (54) | 38 (62) |
| Three | 10 (6) | 7 (11) |
| Not defined | 2 (1) | 1 (2) |
| Analysis | ||
| ITT | 129 (77) | 44 (72) |
| PP | 90 (54) | 35 (57) |
| mITT | 34 (20) | 17 (28) |
| As-treated | 4 (2) | 6 (10) |
| Other | 20 (12) | 10 (16) |
| Unclear | 2 (1) | 2 (3) |
*See online supplementary material.
ITT, intention to treat; mITT, modified intention to treat; PP, per-protocol.