Table 1.
Characteristics of included trials (n = 350)
| Characteristic | No. (%) |
|---|---|
| Author with epi/stats degree | 62 (18) |
| Study type | |
| Superiority/efficacy | 335 (96) |
| Noninferiority/equivalence | 15 (4) |
| Study design | |
| Parallel | 331 (94.5) |
| Split body | 17 (5) |
| Crossover | 2 (0.5) |
| Journal impact factor | |
| None | 23 (7) |
| < 1 | 41 (12) |
| 1–2.4 | 131 (37) |
| 2.5–4.9 | 112 (32) |
| 5–9.9 | 30 (9) |
| ≥ 10 | 13 (4) |
| Total sample size | |
| < 50 | 108 (31) |
| 50–99 | 96 (27) |
| 100–199 | 88 (25) |
| ≥ 200 | 58 (17) |
| Multicentre | 78 (22) |
| Trial registration | |
| Reported in text | 57 (16) |
| Not reported but found online | 37 (11) |
| Unclear | 256 (73) |
| Primary outcome(s) specified | 225 (64) |
| Generation of random sequence | |
| Adequate | 147 (42) |
| Unclear | 203 (58) |
| Allocation concealment | |
| Adequate | 155 (44) |
| Inadequate or unclear | 195 (56) |
| Blinding | |
| Any blinding | 125 (36) |
| Patient | 60 (17) |
| Carer | 28 (8) |
| Outcome assessor | 110 (31) |
| Primary outcome blinded | 97 (28) |
| Unclear | 225 (64) |
| Handling of attrition | |
| Intention to treat | 93 (27) |
| Only follow-up reported | 228 (65) |
| Inadequate | 29 (8) |
| Source of funding | |
| Reported | 153 (44) |
| Full industry | 9 (6) |
| Partial industry | 61 (40) |
| Nonindustry | 49 (32) |
| No external source | 34 (22) |
| Unreported | 197 (56) |