Table 2.
Reporting of randomized controlled trials with multiple arms by trial design
| |
All trials, n = 298 |
Trial design |
||
|---|---|---|---|---|
| Parallel group, n = 221 | Parallel group with factorial, n = 37 | Crossover (n = 40) | ||
|
Reporting item |
|
|
|
|
|
Study hypothesis defined |
238 (79.9) |
173 (78.3) |
33 (89.1) |
32 (80.0) |
|
Baseline characteristics available per group |
253 (84.9) |
196 (88.7) |
28 (75.7) |
29 (72.5) |
|
Results on outcomes available per group |
250 (83.9) |
190 (85.0) |
27 (73.0) |
33 (82.5) |
|
Global test comparison |
|
|
|
|
| Planned |
171 (57.4) |
127 (57.5) |
23 (62.2) |
21 (52.5) |
| Reported |
116 (38.9) |
84 (38.0) |
18 (48.7) |
14 (35.0) |
|
Pairwise test comparisons |
|
|
|
|
| Planned |
180 (60.4) |
144 (65.2) |
11 (29.7) |
25 (62.5) |
| Reported |
204 (68.5) |
162 (73.3) |
15 (40.5) |
27 (67.5) |
|
Sample-size calculation |
|
|
|
|
| Reported |
210 (70.5) |
159 (72.0) |
30 (81.1) |
21 (52.5) |
| Taken into account in the multi-arm design |
41/210 (19.5) |
35/159 (22.0) |
5/30 (16.7) |
1/21 (4.8) |
|
Adjustment method used to control type I error due to multiple-arm designa |
118 (39.6) |
89 (40.3) |
10 (27.0) |
19 (47.50) |
| Title identified the study as a multiple-arm trial | 130 (43.6) | 101 (45.7) | 19 (51.4) | 10 (25.0) |
a For sample-size calculation or for statistical analysis.