Table 4 Author and systematic review characteristics

Author characteristics

 Number of authors

  Mean (SD)

4.2 (1.2)

4.6 (2.6)

4.9 (2.1)

  Median

4

4

5

 Number of institutions represented by authors^a

  Mean (SD)

2.3 (1.0)

2.4 (1.6)

2.8 (1.9)

  Median

2

2

3

 Number of different working countries represented by authors^a

  Mean (SD)

1.3 (0.6)

1.3 (0.7)

1.8 (1.3)

  Median

1

1

1

Questionnaire variables

(n = 6)

(n=30^b)

(n=9^b)

 Authors’ languages

  Mean (SD)

1.3 (0.5)

3.2 (2.2)

4.2 (2.5)

  Median

1

2

4

 Authors’ nationalities

  Mean (SD)

2.0 (0.9)

2.1 (2.2)

2.7 (1.2)

  Median

2

2

2

Methodological inclusion criteria

 RCTs (%)

8 (53.3)

31 (36.9)

4 (23.5)

 Quasi-experiments (%)

3 (20.0)

48 (57.1)

12 (70.6)

 Non-experiments (%)

3 (20.0)

5 (6.0)

1 (5.9)

 Unclear (%)

1 (6.7)

0 (0.0)

0 (0.0)

Scope of search strategy

 Languages of search terms

  Mean (SD)

1 (0.0)

1.3 (1.1)

1.4 (1.5)

  Median

1

1

1

 Databases, registers and journals searched in

  Mean (SD)

34.6 (36.8)

25.3 (23.0)

34.4 (22.0)

  Median

26.0

21.5

26.0

 Experts contacted

  Yes (%)

9 (60.0)

63 (75.0)

14 (82.4)

  No (%)

6 (40.0)

21 (25.0)

3 (17.6)