Table 1. Investigator and trial characteristics.
Columns display the various realized outcomes–primary outcome, recruitment, and completion date–and a sample of 100 trials for which PIs did not accept our invitation to participate.
| Primary outcome | Recruitment | Completion date | Non-responders | ||
|---|---|---|---|---|---|
| Forecaster characteristics | N = 104 | N = 281 | N = 536 | N = 100 | |
| Location | |||||
| Europe | 40 (38.5%) | 82 (29.2%) | 155 (28.9%) | 23 (23.0%) | |
| N. America | 60 (57.7%) | 184 (65.5%) | 347 (64.7%) | 73 (73.0%) | |
| Asia/Oceania | 1 (1.0%) | 7 (2.5%) | 15 (2.8%) | 4 (4.0%) | |
| Other | 3 (2.9%) | 8 (2.8%) | 19 (3.5%) | 0 (0.0%) | |
| H-index | |||||
| median | 22 | 24 | 25 | 25.5 | |
| (95% CI) | (16.3,26.5) | (21.0,26.3) | (23.2,27.3) | (21.3,29.8) | |
| [range] | [1,111] | [1,111] | [0,162] | [1,132] | |
| Trial characteristics | |||||
| Trial Phasea | |||||
| Early (phase 1/2) | 64 (61.5%) | 223 (79.4%) | 427 (79.7%) | 80 (80.0%) | |
| Late (phase 3) | 40 (38.5%) | 58 (20.6%) | 109 (20.3%) | 20 (20.0%) | |
| Randomization | |||||
| Yes | 83 (79.8%) | 182 (64.8%) | 320 (59.7%) | 60 (60.0%) | |
| No | 21 (20.2%) | 99 (35.2%) | 216 (40.3%) | 40 (40.0%) | |
| Indication | |||||
| Cancer | 12 (11.5%) | 64 (22.8%) | 173 (32.3%) | 43 (43.0%) | |
| Non-cancer | 92 (88.5%) | 217 (77.2%) | 363 (67.7%) | 57 (57.0%) | |
| Treatment categoryb | |||||
| Drug/biologic | 70 (67.3%) | 196 (69.8%) | 393 (73.3%) | 83 (83.0%) | |
| Supplement | 13 (12.5%) | 34 (12.1%) | 52 (9.7%) | 0 (0.0%) | |
| Device/procedure | 13 (12.5%) | 32 (11.4%) | 77 (14.4%) | 17 (17.0%) | |
| Behavioral | 10 (9.6%) | 27 (9.6%) | 45 (8.4%) | 10 (10.0%) | |
| Other | 6 (5.8%) | 13 (4.6%) | 32 (6.0%) | 5 (5.0%) | |
| Sample size | 67 (10–2000) | 44.5 (5–1500) | 56 (3–2140) | 51 (10–916) | |
| median (range) | |||||
| Sponsors | |||||
| Commercial | 15 (14.4%) | 33 (11.7%) | 46 (8.6%) | 8 (8.0%) | |
| Non-commercial | 81 (77.9%) | 208 (74.0%) | 399 (74.4%) | 67 (67.0%) | |
| Both | 8 (7.7%) | 40 (14.2%) | 91 (17.0%) | 25 (25.0%) | |
| Primary outcome type | |||||
| Efficacy | 78 (75.0%) | 189 (67.3%) | 362 (67.5%) | 66 (66.0%) | |
| Safety | 8 (7.7%) | 50 (17.8%) | 100 (18.7%) | 19 (19.0%) | |
| Preventive | 7 (6.7%) | 16 (5.7%) | 31 (5.8%) | 7 (7.0%) | |
| Other | 11 (10.6%) | 26 (9.3%) | 43 (8.0%) | 8 (8.0%) | |
| FDA status at trial launchc | |||||
| Approved | 42 (40.4%) | 122 (43.4%) | 248 (46.3%) | 44 (44.0%) | |
| Unapproved | 15 (14.4%) | 51 (18.1%) | 115 (21.5%) | 34 (34.0%) | |
| Not applicable | 47 (45.2%) | 108 (38.4%) | 173 (32.3%) | 22 (22.0%) | |
| Date of trial launch (range) | 06/2013–01/2017 | 06/2013–07/2017 | 05/2013–11/2017 | 07/2013–03/2017 | |
aPhase 2/3 trials were considered early phase trials.