Characteristics of completed NIH funded trials registered within ClinicalTrials.gov* and publication in peer reviewed biomedical journal indexed by Medline within 30 months of study completion, stratified by trial characteristics
| No (%) (n=635) | No (%) published | |
|---|---|---|
| NIH funding institute†: | ||
| National Cancer Institute (NCI) | 49 (8) | 25 (51) |
| National Heart, Lung, and Blood Institute (NHLBI) | 54 (9) | 23 (43) |
| National Institute of Child Health and Human Development (NICHD) | 53 (8) | 23 (43) |
| National Institute on Aging (NIA) | 28 (4) | 11 (39) |
| National Institute of Allergy and Infectious Diseases (NIAID) | 72 (11) | 36 (50) |
| National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) | 55 (9) | 30 (55) |
| National Institute of Mental Health (NIMH) | 76 (12) | 27 (36) |
| National Institute on Alcohol Abuse and Alcoholism (NIAAA)/National Institute on Drug Abuse (NIDA) | 87 (14) | 44 (51) |
| Other institute or not specified | 161 (25) | 75 (47) |
| Focus: | ||
| Treatment | 418 (66) | 206 (49) |
| Prevention or diagnostic | 165 (26) | 70 (42) |
| Other (such as health services research or basic science) | 52 (8) | 18 (35) |
| Purpose‡: | ||
| Safety and efficacy | 149 (36) | 71 (48) |
| Efficacy only | 224 (54) | 115 (51) |
| Safety only | 20 (5) | 11 (55) |
| Pharmacokinetics | 25 (6) | 9 (36) |
| Conducted under FDA IND or IDE‡: | ||
| Yes | 79 (22) | 48 (61) |
| No | 282 (78) | 140 (50) |
| Phase‡: | ||
| I | 61 (15) | 27 (44) |
| I/II or II | 137 (33) | 65 (47) |
| II/III or III | 53 (13) | 32 (60) |
| IV | 36 (9) | 18 (50) |
| No phase designated | 131 (31) | 64 (49) |
| Design, treatment groups§: | ||
| Single arm trial | 113 (19) | 45 (40) |
| Multiple arm trial | 470 (81) | 231 (49) |
| Design, control group among multiple arm studies§: | ||
| Placebo control group | 219 (47) | 105 (48) |
| At least one active control group | 251 (53) | 126 (50) |
| Design, group assignment among multiple arm studies§: | ||
| Randomisation used | 451 (96) | 221 (49) |
| Randomisation not used | 19 (4) | 10 (53) |
| Data monitoring board§: | ||
| Yes | 176 (56) | 93 (53) |
| No | 140 (44) | 64 (46) |
| Population studied included children: | ||
| Yes | 153 (24) | 68 (44) |
| No | 482 (76) | 226 (47) |
| Population studied included older adults (age ≥65): | ||
| Yes | 331 (52) | 153 (46) |
| No | 304 (48) | 141 (46) |
| Trial enrolment (target or actual): | ||
| <100 participants | 334 (55) | 149 (45) |
| ≥100 participants | 278 (45) | 133 (48) |
| Trial location includes at least one US enrolment site: | ||
| Yes | 524 (92) | 241 (46) |
| No | 45 (8) | 25 (56) |
| Trial completion date: | ||
| Before 2007 | 269 (42) | 98 (36) |
| During 2007-8 | 366 (58) | 196 (54) |
| Trial results posted on ClinicalTrials.gov: | ||
| Yes | 26 (4) | 11 (42) |
| No | 609 (96) | 283 (47) |
NIH=National Institutes of Health; FDA=Food and Drug Administration; IND=Investigational New Drug Application; IDE=Investigational Device Exemption.
*All data elements not provided for each registered trial.
†Clinical trials cofunded by multiple NIH institutes assigned to institute listed first in ClinicalTrials.gov registration.
‡Data provided only for treatment clinical trials.
§Data provided only for treatment, prevention, and diagnostic clinical trials.