Table 1.

Characteristics of included studies. Values are numbers (percentages) unless stated otherwise

Characteristics	All (37 studies)	The BMJ (21 studies)	PLOS Medicine (16 studies)
Geographical area of lead country:
Europe	25 (67)	17 (80)	8 (50)
Australia and New Zealand	4 (11)	1 (5)	3 (19)
Northern America	3 (8)	1 (5)	2 (12.5)
Africa	3 (8)	1 (5)	2 (12.5)
East Asia	1 (3)	0 (0)	1 (6)
Middle East	1 (3)	1 (5)	0 (0)
Type of intervention:
Drug	20 (54)	13 (62)	7 (44)
Device	8 (22)	8 (38)	0 (0)
Complex intervention	9 (24)	0 (0)	9 (56)
Medical specialty:
Infectious disease	12 (33)	4 (19)	8 (50)
Rheumatology	5 (14)	5 (24)	0 (0)
Endocrinology/nutrition	4 (11)	1 (5)	3 (19)
Paediatrics	3 (8)	2 (9)	1 (6)
Mental health/addiction	2 (5)	1 (5)	1 (6)
Obstetrics	2 (5)	1 (5)	1 (6)
Emergency medicine	2 (5)	2 (9)	0 (0)
Geriatrics	2 (5)	0 (0)	2 (13)
Other	5 (14)	5 (24)	0 (0)
Designs:
Superiority (head to head)	18 (49)	15 (71)	3 (19)
Superiority (factorial)	1 (3)	1 (5)	0 (0)
Superiority (clusters)	8 (21)	1 (5)	7 (43)
Non-inferiority+superiority (head to head)	4 (11)	1 (5)	3 (19)
Non-inferiority (head to head)	6 (16)	3 (14)	3 (19)
Median (interquartile range) sample size	432 (213-1070)*	221 (159-494)	1047 (433-2248)*
Private sponsorship:
No	26 (70)	15 (71)	11 (69)
Provided device	1 (3)	1 (5)	0 (0)
Provided intervention	1 (3)	0 (0)	1 (6)
Provided drug	5 (13)	1 (5)	4 (25)
Provided drug and some financial support	2 (5)	2 (9)	0 (0)
Provided partial financial support	1 (3)	1 (5)	0 (0)
Provided total financial support	1 (3)	1 (5)	0 (0)
Statement of availability:
Ask to contact by email	23 (62)	17 (81)	6 (38)
Explain how to retrieve data (eg, platform)	9 (24)	0 (0)	9 (56)
State “no additional data available”	2 (5)	2 (9)	0 (0)
Ask to contact by mail	1 (3)	0 (0)	1 (6)
Embargo	1 (3)	1 (5)	0 (0)
No statement	1 (3)	1 (5)	0 (0)

Rounded percentages add up to 100% for each variable.

^*Exact sample size was not reported for one cluster trial in PLOS Medicine.