Table 4 Characteristics of trials with no treatment effect estimate or p-value reported at ClinicalTrials.gov and those for which p-values could be calculated
Characteristics | Categories | Trials with no treatment effect estimate or p-value reported (N = 1423) | Trials with no treatment effect estimate or p-value reported for which p-values could be calculated (N = 929) |
|---|---|---|---|
Phase of the study | Phase 3 Phase 4 | 728 (51) 695 (49) | 440 (47) 489 (53) |
Intervention type | Drug Mixed interventions Biological Device Other | 1014 (71) 148 (10) 96 (7) 97 (7) 68 (5) | 676 (73) 92 (10) 55 (6) 57 (6) 49 (5) |
Control group | Placebo or no treatment Active treatment | 516 (36) 907 (64) | 347 (37) 582 (63) |
Sponsorship | Industry totally or partly Academic only | 1055 (74) 368 (26) | 674 (73) 255 (27) |
Countries | Single country Multiple countries Not reported | 982 (69) 292 (21) 149 (10) | 672 (72) 163 (18) 94 (10) |
Location | At least one site in the USA No site in the USA Not reported | 822 (58) 452 (32) 149 (10) | 529 (57) 306 (33) 94 (10) |
Subject to the FDAAA | Yes No Not reported | 843 (59) 556 (39) 24 (2) | 521 (56) 390 (42) 18 (2) |
Centers | Multicenter Single center Not reported | 696 (49) 578 (41) 149 (10) | 437 (47) 398 (43) 94 (10) |
Sample size | Median (Q1-Q3) | 156 (60–378) | 146 (60–372) |
Time to results first received at ClinicalTrials.gov (month) | Median Q1-Q3) | 17.1 (12.0–32.3) | 17.8 (12.1–32.9) |