Table 2.
Reporting of Results to ClinicalTrials.gov.*
| Variable | All Trials (N = 13,327) | Industry Trials (N = 8736) | NIH Trials (N = 1899) | Other Trials (N = 2692) |
|---|---|---|---|---|
| Results reported by September 2013 — no. (%)† | 5110 (38.3) | 3624 (41.5) | 739 (38.9) | 747 (27.7) |
| Results reported by 12 mo after primary completion — no. (%) | 1790 (13.4) | 1483 (17.0) | 153 (8.1) | 154 (5.7) |
| Median mo until reporting of results (IQR)‡ | 17 (13–29) | 16 (13–26) | 23 (14–36) | 21 (14–30) |
| Trials with certification or extension request by September 2013 | ||||
| No. of trials (%) | 2100 (15.8) | 2015 (23.1) | 51 (2.7) | 34 (1.3) |
| Results reported by September 2013 — no./total no. (%) | 482/2100 (23.0) | 466/2015 (23.1) | 14/51 (27.5) | 2/34 (5.9) |
| Median mo until reporting of results (IQR)‡ | 26 (19–36) | 26 (19–36) | 26 (19–33) | 20 (16–23) |
| Trials without certification or extension requests by September 2013 | ||||
| No. of trials (%) | 11,227 (84.2) | 6721 (76.9) | 1848 (97.3) | 2658 (98.7) |
| Results reported by September 2013 — no./total no. (%) | 4628/11,227 (41.2) | 3158/6721 (47.0) | 725/1848 (39.2) | 745/2658 (28.0) |
| Median mo until reporting of results (IQR)‡ | 16 (13–27) | 14 (13–24) | 23 (14–36) | 21 (14–30) |
| Results reported or certification or extension request submitted by September 2013 — no. (%) | ||||
| No results reported and no certification or extension request submitted | 6599 (49.5) | 3563 (40.8) | 1123 (59.1) | 1913 (71.1) |
| No results reported but certification or extension request submitted | 1618 (12.1) | 1549 (17.7) | 37 (1.9) | 32 (1.2) |
| Results reported§ | 5110 (38.3) | 3624 (41.5) | 739 (38.9) | 747 (27.7) |
| Results reported or certification or extension request submitted by 12 mo after primary completion — no./total no. (%) | ||||
| No results reported and no certification or extension request submitted | 10,706/13,314 (80.4) | 6455/8728 (74.0) | 1719/1895 (90.7) | 2532/2691 (94.1) |
| No results reported but certification or extension request submitted | 818/13,314 (6.1) | 790/8728 (9.1) | 23/1895 (1.2) | 5/2691 (0.2) |
| Results reported§ | 1790/13,314 (13.4) | 1483/8728 (17.0) | 153/1895 (8.1) | 154/2691 (5.7) |
*
IQR denotes interquartile range.
†
The percentage of trials was not adjusted for differing lengths of time from the primary completion date until the database download in September 2013.
‡
The median number of months was calculated for trials that had data regarding the primary completion date and the date that results were first posted at ClinicalTrials.gov. If the primary completion date was missing, then the completion date or the date when the record was last verified was used.
§
This category includes trials that reported results, including those that submitted certification or extension requests.