Table 3 Moderators of the Effect of Health Coaching Interventions for T2DM: Sample-weighted Average Effect Sizes (ES)

Moderators

N

k

Levels of the moderator

Q

p

g + (95% CI)

β

SE

p

 Age (in years)

2928

18

0.19

0.01

0.442

 Gender (percentage of females)

2857

17

−0.13

0.00

0.603

Methodological moderators

 Number of BCTs used

3222

20

−0.36

0.02

0.107

 Study length

3222

20

0.14

0.01

0.535

 Intervention length

1366

6

−0.04

0.05

0.916

 Follow-up length

1366

6

−0.25

0.05

0.574

 Type of control group

3222

20

0.69

0.406

1078

6

Active control

0.24 (0.10, 0.37)

2144

14

Usual care

0.32 (0.417, 0.46)

 Type of intervention provider

3222

20

1.24

0.538

2182

12

Healthcare professional

0.25 (0.10, 0.39)

568

4

Coaches

0.36 (0.06, 0.65)

472

4

Assistants/students

0.37 (0.25, 0.48)

 Mode of Delivery

3222

20

1.17

0.556

1275

6

Telephone only

0.23 (0.05, 0.42)

1134

8

Telephone & FtF

0.36 (0.20, 0.51)

813

6

Other combinations

0.25 (0.01, 0.48)

 Primary outcome measure

3222

20

4.20*

0.040

2750

16

HbA1c

0.32 (0.20, 0.45)

472

4

Others

0.10 (0.03, 0.17)

 Theory use in intervention development

3222

20

1.34

0.247

2532

14

Used

0.24 (0.16, 0.32)

690

6

Not used

0.43 (0.15, 0.72)

 MI theory use

3222

20

0.23

0.632

2108

9

Used

0.26 (0.15, 0.37)

1114

11

Not used

0.32 (0.14, 0.50)