From: Reporting of analyses from randomized controlled trials with multiple arms: a systematic review
All trials, n = 298 | Trial design | |||
---|---|---|---|---|
Parallel group, n = 221 | Parallel group with factorial, n = 37 | Crossovera, n = 40 | ||
No. of study groups | ||||
3 | 172 (57.7) | 152 (68.8) | 0 (0.0) | 20 (50.0) |
4 | 84 (28.2) | 39 (17.7) | 34 (91.9) | 11 (27.5) |
> 4 | 42 (14.1) | 30 (13.6) | 3 (8.1) | 9 (22.5) |
Common specialties | ||||
Anesthesia | 54 (18.1) | 47 (21.3) | 3 (8.1) | 4 (10.0 |
Endocrinology | 32 (10.7) | 20 (9.1) | 5 (13.5) | 7 (17.5) |
Cardiology | 31 (10.4) | 25 (11.3) | 6 (16.2) | 0 (0.0) |
Infectious disease | 22 (7.4) | 20 (9.1) | 1 (2.7) | 1 (2.5) |
Rheumatology | 19 (6.4) | 18 (8.1) | 1 (2.7) | 0 (0.0) |
Intervention | ||||
Drug | 192 (64.4) | 148 (68.0) | 22 (59.5) | 22 (55.0) |
Surgery or procedure | 17 (5.7) | 12 (5.4) | 1 (2.7) | 4 (10.0) |
Counseling or lifestyle interventions | 47 (15.8) | 33 (14.9) | 10 (27.0) | 4 (10.0) |
Equipment or device | 26 (8.7) | 19 (8.6) | 2 (5.4) | 5 (12.5) |
Others | 16 (6.7) | 5 (1.7) | 2 (0.7) | 9 (3.0) |
Study centers | ||||
Single | 80 (26.9) | 54 (24.4) | 8 (21.6) | 18 (5.0) |
Multiple | 141 (47.3) | 110 (49.8) | 24 (64.9) | 7 (13.5) |
Not reported | 77 (25.8) | 57 (25.8) | 5 (13.5) | 15 (37.5) |
No. of randomized patients per: | ||||
Trial, median (10th to 90th percentile) | 136 (25 to 800) | 148 (45 to 650) | 468 (120 to 1653) | 21 (12 to 61) |
Arm, median (10th to 90th percentile) | 39 (7 to 228) | 43 (12 to 204) | 117 (30 to 413) | 5 (3 to 16) |
Cluster trial | 13 (4.4) | 8 (3.6) | 3 (8.1) | 2 (5.0) |
Trial type | ||||
To show superiority | 260 (87.3) | 195 (88.8) | 33 (89.2) | 32 (80.0) |
To show non-inferiority or equivalence | 12 (4.0) | 8 (3.6) | 4 (10.8) | 0 (0.0) |
Pharmacokinetic/pharmacodynamic objective | 26 (8.7) | 18 (8.1) | 0 (0.0) | 8 (20.0) |
Randomization design | ||||
Balanced | 263 (88.3) | 190 (86.0) | 33 (89.2) | 40 (100.0) |
Unbalanced | 30 (10.1) | 28 (12.7) | 2 (5.4) | 0 (0.0) |
Unclear | 5 (1.7) | 3 (1.3) | 2 (5.4) | 0 (0.0) |
Funding source | ||||
Solely or partially industry | 101 (33.9) | 77 (34.8) | 11 (29.7) | 13 (32.5) |
Public | 118 (39.6) | 87 (39.4) | 14 (37.8) | 17 (42.5) |
None | 8 (2.7) | 6 (2.7) | 1 (2.7) | 1 (2.5) |
Unknown | 71 (23.8) | 51 (23.1) | 11 (29.8) | 9 (22.5.0) |
Trial registration reported | 144 (48.3) | 109 (49.3) | 27 (73.0) | 8 (20.0) |