All sample (767) | 19.8 | 29.2 | 12.9 | |
Concealment of allocation | | | | |
Yes (264)† | 14.8 | 24.2 | 8.0 | 1 (ref)‡ |
No (503) | 22.5 | 31.8 | 15.5 | 1.66 (1.12–2.46) |
Justification of unblinded trials | | | | |
Yes (36)† | 8.3 | 19.4 | 5.6 | 1 (ref)‡ |
No (280) | 26.1 | 41.1 | 18.2 | 2.70 (1.09–6.66) |
Type of treatment for control group | | | | |
Placebo (273)† | 11.7 | 18.7 | 7.0 | 1 (ref)‡ |
Alternative active treatment (366) | 21.3 | 33.6 | 14.5 | 1.39 (0.88–2.20) |
No treatment (105) | 35.2 | 40.0 | 21.9 | 2.47 (1.37–4.47) |
Not a proper control group (23) | 21.7 | 34.8 | 17.4 | 1.75 (0.52–5.81) |
Reporting of statistical methods | | | | |
Yes: some information reported (739)† | 18.9 | 27.9 | 12.0 | 1 (ref)§ |
No information about statistical methods (28) | 42.9 | 64.3 | 35.7 | 3.77 (1.42–9.98) |
Sample size estimation | | | | |
Shown (320)† | 14.4 | 23.1 | 6.9 | 1 (ref)‡ |
Not shown (447) | 23.7 | 33.6 | 17.2 | 1.49 (1.02–2.19) |
Rules to stop the trial | | | | |
Reported (269)† | 12.1 | 21.6 | 6.4 | 1 (ref)‡ |
Not reported (498) | 23.7 | 32.9 | 16.3 | 1.33 (0.99–1.78) |
Baseline comparison of groups | | | | |
Presented (679)† | 18.6 | 27.1 | 11.6 | 1 (ref)‡ |
Not presented (88) | 29.5 | 45.5 | 22.7 | 1.80 (1.05–3.08) |
Outcome | | | | |
Survival (166)† | 22.9 | 30.7 | 13.9 | 1 (ref)§ |
Other (601) | 19.0 | 28.8 | 12.6 | 0.52 (0.33–0.84) |