|
Area
|
|
Health
|
117 (95.1)
|
|
Education
|
3 (2.4)
|
|
Social
|
3 (2.4)
|
|
Country
|
|
USA
|
20 (16.3)
|
|
UK
|
20 (16.3)
|
|
Netherlands
|
15 (12.2)
|
|
African
|
15 (12.2)
|
|
Australasian
|
12 (9.8)
|
|
Asian
|
10 (8.1)
|
|
Canada
|
9 (7.3)
|
|
South or Central American
|
8 (6.5)
|
|
Other European
|
6 (4.9)
|
|
France
|
5 (4.1)
|
|
Multiple
|
3 (2.4)
|
|
Received industry support
|
|
Yes
|
6 (4.9)
|
|
No
|
108 (87.8)
|
|
Unclear
|
9 (7.3)
|
|
Stated reasons for use
|
|
Everyone receives
|
51 (41.5)
|
|
None stated
|
45 (36.6)
|
|
Logistical or practical
|
43 (35.0)
|
|
Methodological
|
15 (12.2)
|
|
Time effects
|
13 (10.6)
|
|
Other
|
10 (8.1)
|
|
Cluster-level randomization
|
9 (7.3)
|
|
Prevent contamination bias
|
8 (6.5)
|
|
Encourage participation
|
7 (5.7)
|
|
Incorporate randomization
|
6 (4.9)
|
|
Efficiency grounds
|
6 (4.9)
|
|
Social or political acceptability
|
3 (2.4)
|
|
Fine-tune intervention
|
3 (2.4)
|
