Table 1. Characteristics of Included Randomized Clinical Trial Protocols.
| Trial characteristics | Trial approval, No. (%) | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| 2000-2003 | 2012 | 2016 | |||||||
| SGA | All trials (n = 894) |
SGA | All trials (n = 257) |
SGA | All trials (n = 292) |
||||
| Not planned ( 642 [71.8%]) | Planned (252 [28.2%]) | Not planned (164 [63.8%]) | Planned (93 [36.2%]) | Not planned (196 [67.1%]) | Planned (96 [32.9%]) | ||||
| Median (IQR), target sample size | 200 (80-471) | 521 (229-1030) | 260 (100-610) | 165 (71.5-432) | 600 (354-1500) | 300 (100-720) | 164 (75-416) | 303 (150-600) | 199 (100-490) |
| Center status | |||||||||
| Multicenter | 500 (77.9) | 241 (95.6) | 741 (82.9) | 119 (72.6) | 91 (97.8) | 210 (81.7) | 131 (66.8) | 84 (87.5) | 215 (73.6) |
| Single center | 139 (21.7) | 10 (4.0) | 149 (16.7) | 45 (27.4) | 2 (2.2) | 47 (18.3) | 65 (33.2) | 12 (12.5) | 77 (26.4) |
| Unclear | 3 (0.5) | 1 (0.4) | 4 (0.4) | 0 | 0 | 0 | 0 | 0 | 0 |
| Study design | |||||||||
| Parallel | 592 (92.2) | 244 (96.8) | 836 (93.5) | 145 (88.4) | 86 (92.4) | 231 (89.9) | 172 (87.8) | 95 (99.0) | 267 (91.4) |
| Crossover | 40 (6.2) | 1 (0.4) | 41 (4.6) | 10 (6.1) | 1 (1.1) | 11 (4.3) | 11 (5.6) | 1 (1.0) | 12 (4.1) |
| Factorial | 9 (1.4) | 6 (2.4) | 15 (1.7) | 3 (1.8) | 4 (4.3) | 7 (2.7) | 6 (3.0) | 0 | 6 (2.1) |
| Other | 1 (0.2) | 1 (0.4) | 2 (0.2) | 6 (3.7) | 2 (2.2) | 8(3.1) | 7 (3.6) | 0 | 7 (2.4) |
| Study intention | |||||||||
| Superiority | 456 (71.0) | 196 (77.8) | 652 (72.9) | 130 (79.3) | 73 (78.5) | 203 (79.0) | 160 (81.6) | 79 (82.3) | 239 (81.8) |
| Non-inferiority | 95 (14.8) | 44 (17.5) | 139 (15.5) | 23 (14.0) | 19 (20.4) | 42 (16.3) | 30 (15.3) | 14 (14.6) | 44 (15.1) |
| Unclear | 91 (14.2) | 12 (4.8) | 103 (11.5) | 11 (6.7) | 1 (1.1) | 12 (4.7) | 6 (3.1) | 3 (3.1) | 9 (3.1) |
| Sponsorship | |||||||||
| Industry | 356 (55.5) | 195 (77.4) | 551 (61.6) | 69 (42.1) | 69 (74.2) | 138 (53.7) | 73 (37.2) | 57 (59.4) | 130 (44.5) |
| Investigator | 286 (44.5) | 57 (22.6) | 343 (38.4) | 95 (57.9) | 24 (25.8) | 119 (46.3) | 123 (62.8) | 39 (40.6) | 162 (55.5) |
| Clinical area | |||||||||
| Oncology | 113 (17.6) | 42 (16.3) | 155 (17.3) | 22 (13.4) | 25 (26.9) | 47 (18.3) | 27 (13.8) | 24 (25.0) | 51 (17.5) |
| Cardiovascular | 59 (9.2) | 49 (19.5) | 108 (12.1) | 8 (4.9) | 19 (20.4) | 27 (10.5) | 15 (7.7) | 20 (20.8) | 35 (12.0) |
| Infectious diseases | 60 (9.3) | 27 (10.8) | 87 (9.7) | 6 (3.7) | 3 (3.2) | 9 (3.5) | 4 (2.0) | 3 (3.1) | 7 (2.4) |
| Surgery | 75 (11.7) | 18 (7.2) | 93 (10.4) | 27 (16.5) | 10 (10.8) | 37 (14.4) | 21 (10.7) | 10 (10.4) | 31 (10.6) |
| Pediatrics | 34 (5.3) | 11 (4.4) | 45 (5.0) | 11 (6.7) | 3 (3.2) | 14 (5.4) | 11 (5.6) | 8 (8.3) | 19 (6.5) |
| Other | 301 (46.9) | 105 (41.7) | 406 (45.4) | 90 (54.9) | 33 (35.5) | 123 (47.9) | 118 (60.2) | 31 (32.3) | 149 (51.0) |
Abbreviation: SGA, subgroup analysis.