Sample studies

Research design

Qualitative (sample size)

Quantitative (sample size)

Other

Study 1

Case study

Not specified (NS)

Not specified (NS)

Study 2

Qualitative

51

-

Study 3

Mixed methods

18

100

Study 4

Quantitative

-

1259

Study 5

Case study

42

-

Study 6

Mixed methods

NS

1775

Study 7

Qualitative

6

-

Study 8

Quantitative

-

393

Study 9

Quantitative

-

402

Study 10

Mixed methods

16

130

Study 11

Mixed methods

NS

79

Study 12

Case study

13

-

Study 13

Mixed methods

19

NS

Study 14

Mixed methods

14

282

Study 15

Mixed methods

58

NS

Study 16

Mixed methods

10

170

Study 17

Mixed methods

5

75

Study 18

Case study

4

85

Study 19

Qualitative

1

-

Study 20

Quantitative

NS

NS

Study 21

Qualitative

50

-

Study 22

Mixed methods

12

535

Study 23

Qualitative

207

-

Total average:

30

400