Table 1

Characteristics of the 200 articles included.

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)


* Comparisons between superiority and noninferiority trials, ** Fisher's exact test, *** Mann-Whitney test

Gayet-Ageron et al. BMC Medical Research Methodology 2010 10:93   doi:10.1186/1471-2288-10-93

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