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. 2022 Oct 18;9:1008683. doi: 10.3389/fmed.2022.1008683

Table 2.

Trial characteristics and designs for phase II–phase III trials in different years.

Category Information 2013
(N = 57)
2014
(N = 313)
2015
(N = 90)
2016
(N = 34)
2017
(N = 43)
2018
(N = 38)
2019
(N = 66)
2020
(N = 54)
2021
(N = 65)
Allocation Randomized, n (%) 57 (100.0%) 310 (99.0%) 88 (97.8%) 34 (100.0%) 42 (97.7%) 37 (97.4%) 66 (100.0%) 53 (98.1%) 65 (100.0%)
Not randomized, n (%) 0 (0.0%) 3 (1.0%) 2 (2.2%) 0 (0.0%) 1 (2.3%) 1 (2.6%) 0 (0.0%) 1 (1.9%) 0 (0.0%)
Intervention model Parallel Assignment, n (%) 57 (100.0%) 306 (97.8%) 88 (97.8%) 33 (97.1%) 41 (95.3%) 37 (97.4%) 66 (100.0%) 53 (98.1%) 65 (100.0%)
Crossover Assignment, n (%) 0 (0.0%) 2 (0.6%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%)
Single Group Assignment, n (%) 0 (0.0%) 4 (1.3%) 2 (2.2%) 0 (0.0%) 2 (4.7%) 1 (2.6%) 0 (0.0%) 1 (1.9%) 0 (0.0%)
Factorial Assignment, n (%) 0 (0.0%) 1 (0.3%) 0 (0.0%) 1 (2.9%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%)
Masking Double blind, n (%) 56 (98.2%) 298 (95.2%) 86 (95.6%) 31 (91.2%) 40 (93.0%) 35 (92.1%) 62 (93.9%) 52 (96.3%) 65 (100.0%)
Single blind, n (%) 1 (1.8%) 8 (2.6%) 2 (2.2%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 1 (1.5%) 0 (0.0%) 0 (0.0%)
Open label, n (%) 0 (0.0%) 7 (2.2%) 2 (2.2%) 3 (8.8%) 3 (7.0%) 3 (7.9%) 3 (4.5%) 2 (3.7%) 0 (0.0%)
Test scope Domestic, n (%) 57 (100.0%) 313 (100.0%) 90 (100.0%) 34 (100.0%) 43 (100.0%) 37 (97.4%) 66 (100.0%) 54 (100.0%) 63 (96.9%)
International Multi-center, n (%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 1 (2.6%) 0 (0.0%) 0 (0.0%) 2 (3.1%)
Numbers of group One group, n (%) 0 (0.0%) 2 (0.6%) 1 (1.1%) 0 (0.0%) 2 (4.7%) 2 (5.3%) 0 (0.0%) 0 (0.0%) 0 (0.0%)
Two group, n (%) 31 (54.4%) 160 (51.1%) 44 (48.9%) 14 (41.2%) 16 (37.2%) 12 (31.6%) 34 (51.5%) 24 (44.4%) 36 (55.4%)
Three group, n (%) 25 (43.9%) 128 (40.9%) 35 (38.9%) 15 (44.1%) 20 (46.5%) 18 (47.4%) 26 (39.4%) 23 (42.6%) 21 (32.3%)
≥Four group, n (%) 1 (1.8%) 23 (7.3%) 10 (11.1%) 5 (14.7%) 5 (11.6%) 6 (15.8%) 6 (9.1%) 4 (7.4%) 8 (12.3%)
Control assignment Placebo control only, n (%) 37 (64.9%) 198 (63.3%) 64 (71.1%) 24 (70.6%) 31 (72.1%) 22 (57.9%) 51 (77.3%) 44 (81.5%) 55 (84.6%)
Positive control only, n (%) 10 (17.5%) 71 (22.7%) 13 (14.4%) 4 (11.8%) 3 (7.0%) 2 (5.3%) 11 (16.7%) 5 (9.3%) 2 (3.1%)
Both, n (%) 7 (12.3%) 36 (11.5%) 7 (7.8%) 3 (8.8%) 3 (7.0%) 9 (23.7%) 2 (3.0%) 2 (3.7%) 6 (9.2%)
Neither, n (%) 3 (5.3%) 8 (2.6%) 6 (6.7%) 3 (8.8%) 6 (14.0%) 5 (13.2%) 2 (3.0%) 3 (5.6%) 2 (3.1%)
Sample sizes ≤ 100 cases, n (%) 2 (9.5%) 21 (6.7%) 9 (10.0%) 5 (14.7%) 4 (9.3%) 5 (13.2%) 5 (7.6%) 6 (11.1%) 6 (9.5%)
101–300 cases, n (%) 13 (61.9) 176 (56.2%) 52 (57.8%) 18 (52.9%) 29 (67.4%) 23 (60.5%) 54 (81.8%) 44 (81.5%) 46 (73.0%)
301–1000 cases, n (%) 6 (28.6%) 78 (24.9%) 29 (32.2%) 11 (32.4%) 10 (23.3%) 10 (26.3%) 7 (10.6%) 3 (5.6%) 10 (15.9%)
>1000 cases, n (%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%) 1 (1.9%) 1 (1.6)
Sample sizes Median (IQR) 240 (180–432) 240 (216–432) 240 (180–480) 240 (144–360) 240 (144–294) 240 (180–354) 222 (120–240) 216 (120–240) 216 (138–240)