Table 2 Characteristics of reports of randomised non-inferiority and equivalent trials published in 2009
| Â | Â | Trial type | |
|---|---|---|---|
| Â | All trials (n = 209) | Non-inferiority (n = 167) | Equivalence (n = 42) |
Journal type: | Â | Â | Â |
General medical journal | 80 (38) | 68 (41) | 12 (29) |
Speciality journal | 129 (62) | 99 (59) | 30 (71) |
Number of treatment groups | Â | Â | Â |
Two | 163 (78) | 130 (78) | 33 (79) |
Three | 31 (15) | 26 (16) | 5 (12) |
Four | 15 (7) | 11 (7) | 4 (10) |
Placebo arm | Â | Â | Â |
Inclusion of a placebo arm | 25 (12) | 22 (13) | 3 (7) |
To show non-inferiority or equivalence of | 10 (5) | 8 (5) | 2 (5) |
1 or 2 experimental treatments v placebo | |||
To show superiority of 1 or 2 treatments | 11 (5) | 10 (6) | 1 (2) |
compared by non-inferiority or equivalence | |||
analysis | |||
Sample size | Â | Â | Â |
Median per trial (IQR) | 338 (174, 686) | 379 (202, 714) | 198 (90, 424) |
Comparison | Â | Â | Â |
Different treatments* | 142 (68) | 121 (73) | 21 (50) |
Same treatments* | 80 (38) | 59 (35) | 21 (50) |
Two strategies | 49 (23) | 32 (19) | 17 (41) |
Two doses | 27 (13) | 24 (14) | 3 (7) |
Two durations | 5 (2) | 3 (2) | 2 (5) |