Participation of an epidemiologist/biostatistician and the general characteristics of a controlled clinical trial
| Epidemiologist/biostatistician | ||||
|---|---|---|---|---|
| Yes % (n=178) | No % (n=289) | Total | p Value1-150 | |
| Type of design | ||||
| Parallel | 88.2 | 82.7 | 84.8 | 0.241 |
| Crossover | 6.7 | 11.1 | 9.4 | |
| Other | 5.1 | 6.2 | 5.8 | |
| Number of participating centres | ||||
| 1 | 33.9 | 60.9 | 50.3 | <0.001 |
| 2–5 | 18.5 | 22.8 | 21.2 | |
| 6+ | 47.2 | 15.9 | 27.8 | |
| Not available | 1.1 | 0.4 | 0.6 | |
| Sample size | ||||
| Up to 100 | 23.0 | 50.9 | 40.3 | <0.001 |
| 101–500 | 38.8 | 33.6 | 35.6 | |
| 501–1000 | 16.3 | 6.9 | 10.5 | |
| 1000+ | 21.9 | 8.7 | 13.7 | |
| Approval by Institutional Review Board (IRB) and informed consent (IC) | ||||
| IRB+/IC+ | 64.6 | 64.0 | 64.2 | 0.559 |
| IRB+/IC− | 7.3 | 9.7 | 8.8 | |
| IRB−/IC+ | 14.6 | 16.3 | 15.6 | |
| IRB−/IC− | 13.5 | 10.0 | 11.4 | |
| Use of blindness | ||||
| Yes | 57.3 | 56.4 | 56.7 | 0.848 |
| No | 42.7 | 43.6 | 43.3 | |
| Treatment given to control group | ||||
| Other treatment | 51.1 | 46.7 | 48.4 | 0.528 |
| Placebo | 36.5 | 37.7 | 37.3 | |
| No treatment | 12.4 | 15.6 | 14.4 | |
| Death as main outcome | ||||
| Yes | 25.3 | 13.2 | 17.8 | 0.001 |
| No | 74.7 | 86.8 | 82.2 | |
| Source of funding | ||||
| Public agency | 37.6 | 29.4 | 32.6 | 0.002 |
| Private firms | 25.8 | 24.9 | 25.3 | |
| Both | 21.4 | 15.2 | 17.6 | |
| None/not reported | 15.2 | 30.5 | 24.6 | |
↵1-150 Obtained by χ2 test. Totals may not total 100% because of rounding.