Table 2.
Characteristics of published parallel group randomised trials
| Characteristic | No of trials (n=70) |
|---|---|
| Intervention: | |
| Drug | 52 |
| Surgery/procedure | 9 |
| Counselling/lifestyle | 7 |
| Equipment | 2 |
| No of study groups: | |
| 2 | 47 |
| 3 | 15 |
| >3 | 8 |
| Blinding: | |
| Blinded in some way | 49 |
| None | 13 |
| Unclear | 8 |
| Study centres: | |
| Single | 24 |
| Multiple | 46 |
| Funding: | |
| Industry only | 45 |
| Industry and non-industry | 11 |
| Non-industry only | 10 |
| None | 3 |
| Unclear | 1 |