Characteristics | Superiority trials (n = 100) | Noninferiority trials (n = 100) | P-value* |
---|---|---|---|
Journals, No. (%) | 0.24** | ||
N Engl J Med | 14 (14) | 21 (21) | |
J Clin Oncol | 5 (5) | 8 (8) | |
JAMA | 6 (6) | 10 (10) | |
Pediatrics | 11 (11) | 7 (7) | |
Lancet | 10 (10) | 4 (4) | |
Other | 54 (54) | 50 (50) | |
Years of publication, No. (%) | 0.99 | ||
2004-2006 | 59 (59) | 59 (59) | |
2007-2009 | 41 (41) | 41 (41) | |
Justification for the treatement difference, No (%) | 0.02 | ||
Yes (by published or pilot studies) | 59 (59) | 49 (49) | |
No | 41 (41) | 61 (61) | |
Medical specialty, No (%) | <0.001 | ||
Cardio-vascular diseases | 14 (14) | 19 (19) | |
Infectious diseases | 3 (3) | 23 (23) | |
Oncology | 6 (6) | 10 (10) | |
Other | 77 (77) | 48 (48) | |
Intervention, No. (%) | 0.02 | ||
Pharmacological | 54 (54) | 73 (73) | |
Surgery | 8 (8) | 3 (3) | |
Strategy (diagnosis or management) | 34 (34) | 18 (18) | |
Other | 4 (4) | 6 (6) | |
Patient categories, No. (%) | 0.18**. | ||
Adults (including elderly) | 77 (77) | 82 (82) | |
Neonates and children < 18 yrs | 18 (18) | 18 (18) | |
Mother and child | 5 (5) | 0 (-) | |
Primary outcome, No. (%) | <0.001 | ||
Dichotomous | 60 (60) | 86 (86) | |
Continuous | 40 (40) | 14 (14) | |
Type of outcome, No. (%) | 0.17 | ||
Mortality | 12 (12) | 19 (19) | |
Other | 88 (88) | 81 (81) | |
Statistician/epidemiologist involved, No. (%) | |||
Yes | 46 (46) | 54 (54) | 0.32 |
No | 54 (54) | 46 (46) | |
Median power (interquartile range) | 0.80 (0.80-0.90) | 0.82 (0.80-0.90) | 0.02*** |
Multicenter trial, No. (%) | 0.001 | ||
Yes | 67 (67) | 86 (86) | |
No | 33 (33) | 14 (14) | |
Median sample size (interquartile range) | 248 (118-633) | 500 (300-900) | <0.001*** |
Funding source, No. (%) | 0.004** | ||
Study supported by the industry | 50 (50) | 70 (70) | |
Study supported by institutional funds | 33 (33) | 25 (25) | |
No funding source or not stipulated | 17 (17) | 5 (5) |