Assessment of key quality parameters of randomised controlled trials by year of publication
| Quality criteria | 1982–86 | 1987–91 | 1992–96 |
|---|---|---|---|
| Randomisation procedure | |||
| Number (%) reporting this information | 38 (46%) | 29 (39%) | 40 (43%) |
| Number (%) in highest quality group | 14 (37%) | 13 (45%) | 26 (65%) |
| Level of blinding of outcome assessment | |||
| Number (%) reporting this information | 73 (88%) | 72 (98%) | 89 (96%) |
| Number (%) in highest quality group | 31 (42%) | 21 (29%) | 44 (49%) |
| Completeness of data in primary analysis | |||
| Number (%) reporting this information | 83 (100%) | 73 (100%) | 93 (100%) |
| Number (%) in highest quality group | 44 (53%) | 30 (41%) | 29 (31%) |