Table 2.
Characteristics of reports of randomised non-inferiority and equivalent trials published in 2009
| |
|
Trial type |
|
|---|---|---|---|
| All trials (n = 209) | Non-inferiority (n = 167) | Equivalence (n = 42) | |
|
Journal type: |
|
|
|
| General medical journal |
80 (38) |
68 (41) |
12 (29) |
| Speciality journal |
129 (62) |
99 (59) |
30 (71) |
|
Number of treatment groups |
|
|
|
| Two |
163 (78) |
130 (78) |
33 (79) |
| Three |
31 (15) |
26 (16) |
5 (12) |
| Four |
15 (7) |
11 (7) |
4 (10) |
|
Placebo arm |
|
|
|
| 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 |
|
|
|
| Median per trial (IQR) |
338 (174, 686) |
379 (202, 714) |
198 (90, 424) |
|
Comparison |
|
|
|
| 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) |
Results are presented as number (%) unless stated otherwise. *Multiple answers possible, IQR: interquartile range.