Table 3 Summary statistics and effect sizes by moderator variable for change in physical activity as a result of internet-delivered interventions

Study Design

Physical activity

0.07

73.68^a

Main outcome

25

0.14^a

0.03

0.09/0.19

69.95^a

Secondary outcome

9

0.15^a

0.04

0.07/0.23

3.73

Design

0.11

73.64^a

Randomised Trial

9

0.13^a

0.04

0.05/0.21

25.36^a

Randomised Controlled Trial

25

0.16^a

0.03

0.09/0.19

48.25^a

Study Quality

0.47

73.28^a

Fair

10

0.13

0.05

0.02/0.20

29.18^a

Good

24

0.15^a

0.02

0.10/0.20

44.10^a

Sample Size

13.14^a

13.14^a

<35 per group

15

0.40^a

0.08

0.25/0.55

17.92

≥35 per group

19

0.12^a

0.02

0.07/0.16

42.70^a

Physical Activity Mode

0.08

73.68^a

Leisure time

15

0.14^a

0.03

0.08/0.19

20.32

Overall

19

0.15^a

0.04

0.08/0.22

53.36^a

Additional Behaviours

0.05

73.70^a

No

21

0.15^a

0.04

0.08/0.22

66.05^a

Yes

13

0.14^c

0.03

0.08/0.19

7.65

Intervention Duration

2.01

66.72^a

0–6 weeks

8

0.11^a

0.04

0.03/0.19

24.63^a

7–12 weeks

17

0.13^a

0.03

0.08/0.19

35.45^a

13+ weeks

8

0.21^a

0.06

0.09/0.33

6.65

Internet and/or Email

0.51

73.25^a

Internet and email

21

0.16^a

0.04

0.09/0.23

34.12

Only internet OR email

13

0.13^a

0.03

0.08/0.18

39.13^a

Comparison Group

10.50

63.25^a

Intervention group

4

0.03

0.06

−0.08/0.14

1.76

Minimal intervention

4

0.43^a

0.12

0.21/0.66

5.80

Standard care

9

0.16^a

0.04

0.09/0.23

23.23^a

Control group

17

0.14^a

0.03

0.07/0.20

32.46

Intervention Attrition

4.59

39.82

Below average (<23%)

16

0.16^a

0.03

0.10/0.23

17.68

Above average (>22%)

12

0.06

0.04

−0.01/0.13

22.14

Participant Characteristics

Age

0.42

71.00^a

< 45 years

19

0.13^a

0.03

0.07/0.18

46.38^a

> 44 years

14

0.15^a

0.03

0.09/0.22

24.61

Gender

0.92

72.83^a

<60% female sample

12

0.10

0.05

0.01/0.19

39.57^a

>59% female sample

22

0.15^a

0.02

0.10/0.20

33.26^a

Health Status

4.13

69.62^a

General population

17

0.11^a

0.03

0.06/0.17

44.06^a

Chronic diseased

12

0.19^a

0.04

0.11/0.28

22.25

Overweight

5

0.28^a

0.11

0.07/0.48

3.31

Physical Activity Level

8.83^a

64.92^a

Not screened for

25

0.12^a

0.02

0.08/0.16

54.29^a

Sedentary

9

0.37^c

0.08

0.21/0.52

10.63

Intervention Features

Intervention Contacts

1.06

72.57^a

Less than 10

22

0.13^a

0.03

0.07/0.18

63.03^a

10 or more

10

0.18^a

0.04

0.10/0.25

9.54

Tailored

1.61

72.14^a

Comprehensive tailoring

6

0.13

0.06

0.02/0.24

1.92

Limited tailoring

12

0.09

0.04

0.02/0.18

39.71^a

No tailoring

16

0.16^a

0.03

0.11/0.22

30.51

SCT

6.85

66.91^a

Yes

16

0.20^a

0.03

0.14/0.27

20.54

No

18

0.09^a

0.03

0.03/0.15

46.37^a

TTM

0.80

72.95^a

Yes

9

0.11^a

0.03

0.04/0.19

34.90^a

No

25

0.15^a

0.03

0.10/0.21

38.05

Education Components

8.02^a

65.73^a

Yes

24

0.20^a

0.03

0.14/0.26

32.50

No

10

0.08

0.03

0.01/0.14

33.23^a

Goal Setting

1.05

72.70^a

Yes

19

0.16^a

0.03

0.10/0.22

40.23^a

No

15

0.12^a

0.03

0.06/0.12

32.47^a

Self-Monitoring

3.85

69.91^a

Yes

18

0.20^a

0.04

0.13/0.27

25.70

No

16

0.11^a

0.03

0.06/0.16

44.21^a

Email Reminders

0.11

73.64^a

Yes

22

0.15^a

0.03

0.09/0.21

34.27

No

12

0.13^a

0.03

0.07/0.19

39.37^a

Updated Content

4.79

68.96^a

Yes

17

0.19^a

0.03

0.13/0.26

34.68^a

No

17

0.10^a

0.03

0.04/0.16

34.28^a

Quizzes

0.10

73.66^a

Yes

12

0.15^a

0.04

0.08/0.22

21.16

No

22

0.14^a

0.03

0.08/0.19

52.49^a

Asynchronous Communication

0.58

Yes

15

0.16

0.04

0.09/0.23

32.37 ^a

No

19

0.13

0.03

0.08/0.18

40.79 ^a