Table 1. Description of Interim Publications of Ongoing Trials (n = 171).
| Characteristics | No. (%)a |
|---|---|
| Reason for interim analysis | |
| Protocol prespecified | 68 (40) |
| Otherb | 17 (10) |
| None | 86 (50) |
| Journal | |
| High impact factor (≥20) | 26 (15) |
| Top-5 impact factor for general medical journal | 14 (8) |
| Altmetric attention score, median (range)c | 6 (1-531) |
| Results reported | |
| Efficacy | 155 (91) |
| Safety | 16 (9) |
| Clinical area | |
| Oncology | 48 (28) |
| Surgery | 30 (18) |
| Cardiology | 18 (11) |
| Infectious disease | 16 (9) |
| Endocrinology | 13 (8) |
| Funding | |
| Industry (solely) | 61 (36) |
| Industry (partly) | 17 (10) |
| Government | 30 (18) |
| Foundation or university | 29 (17) |
| Design | |
| Superiority | 148 (87) |
| Noninferiority | 23 (13) |
| Control group | |
| Placebo | 61 (36) |
| Active | 101 (59) |
| Placebo plus active | 9 (5) |
| Trial participants | |
| No. of participants, median (IQR) | 130 (60-468) |
| ≤50 participants | 32 (19) |
| Follow-up time, wk | |
| Median (IQR) | 48 (12-91) |
| ≤4 | 26 (15) |
| Intervention tested | |
| Drug | 81 (47) |
| Surgery or procedure | 54 (32) |
| Therapy | 26 (15) |
| Device | 10 (6) |
Abbreviation: IQR, interquartile range.
a
Data are expressed as No. (%) unless otherwise specified.
b
Examples of other reasons include response to recently released results about the same intervention and desire for publication to support upcoming research funding application.
c
Altmetric attention scores were available for 83 articles.