Table 2 Meta-regression of the effect of intervention´s characteristics on pooled glycated hemoglobin (N = 20)

Country

0.00%

US

18

-0.28**

-0.47; -0.09

Netherland

1

-0.82

-1.85; 0.21

UK

1

-0.06

-0.88; 0.77

Year

1.74%

Prior 2001

2

-0.51

-1.29; 0.26

2001-2006

6

0.32

-0.52; 1.15

2007-2012

12

0.18

-0.60; 0.97

Setting

0.00%

Primary Care

9

-0.23

-0.58; 0.11

Community center

6

-0.03

-0.48; 0.41

Other

5

-0.24

-0.74; 0.26

Mean HbA1c at baseline in intervention group

0.08%

HbA1c < 9%

10

-0.39**

-0.96; 0.17

HbA1c ≥ 9%

10

0.06

-0.32; 0.43

Target population

3.33%

Ethnic minority

10

-0.30

-0.58; -0.04

Rural ethnic minority

3

0.31

-0.41; 1.03

Women from ethnic minority group

2

-0.23

-1.04; 0.58

Other (elderly or low income or low literacy)

5

-0.05

-0.47; 0.36

Ethnic minority group

0.00%

African-American

7

-0.10

-0.48; 0.28

Latinos

7

-0.31

-0.80; 0.17

Asiatic

2

-0.54

-1.28; 0.20

Multi-ethnic

4

-0.15

-0.66; 0.35

Individual Vs Group delivered

0.00%

Individual

7

-0.45

-0.75; -0.14

Group

7

0.13

-0.29; 0.56

Both

4

0.32

-0.14; 0.79

Patients accompanied by family

0.00%

No

5

-0.23**

-0.44; -0.04

Yes

15

-0.38

-0.84; 0.07

Face to face Vs. telecommunication

0.00%

Exclusively face to face

12

-0.37**

-0.62; -0.12

Exclusively telecommunication

3

-0.08

-0.53; 0.37

Combining face to face and telecommunication

5

0.33

-0.11; 0.77

Teaching methods

0.00%

Didactic

0.39%

Yes

14

-0.30**

-0.53; -0.07

No

6

-0.03

-0.42; 0.35

Goal setting negotiated

0.00%

Yes

8

-0.29**

-0.57; -0.01

No

12

-0.03

-0.41; 0.34

Goal setting dictated

0.00%

Yes

7

-0.26

-0.55; 0.02

No

13

-0.09

-0.48; 0.29

Situational problem solving

0.00%

Yes

10

-0.28**

-0.50; -0.06

No

10

-0.08

-0.47; 0.30

Cognitive reframing

0.00%

Yes

4

-0.47**

-0.91; -0.03

No

16

0.20

-0.29; 0.68

Number of teaching methods used

0.00%

1

4

-0.58**

-1.04; -0.12

2

10

0.37

-0.16; 0.92

3 or more

4

0.27

-0.27; 0.80

Content

Diet

0.00%

Yes

18

-0.35*

-0.54; -0.15

No

1

-0.74

-2.00; 0.50

Exercise

0.00%

Yes

15

-0.33*

-0.54; -0.12

No

4

-0.20

-0.68; 0.28

Blood glucose self-monitoring

0.00%

Yes

13

-0.26*

-0.48; -0.03

No

6

-0.39

-0.81; 0.04

Basic diabetes knowledge

0.00%

Yes

8

-0.28*

-0.53; -0.02

No

11

-0.21

-0.60; 0.17

Medication adherence

0.00%

Yes

9

-0.25*

-0.49; -0.05

No

10

-0.19

-0.58; 0.20

Psycho-social

0.00%

Yes

11

-0.18*

-0.40; 0.03

No

9

-0.38

-0.76; 0.01

Number of contents

5.17%

1 or 2

4

-0.36

-0.84; 0.12

3 or 4

9

0.02

-0.55; 0.58

5 or more

7

0.84

-0.48; 0.65

Educators

Nurse

2.59%

Yes

5

-0.02

-0.43; 0.39

No

14

-0.29*

-0.52; -0.06

Dietician

0.77%

Yes

11

-0.10

-0.27; 0.47

No

8

-0.35*

-0.62; -0.08

Psychologist

2.47%

Yes

1

0.05

-0.65; 0.76

No

18

-0.30*

-0.50; -0.11

Physician

0.00%

Yes

2

0.21

-0.29; 0.72

No

17

-0.33*

-0.54; -0.13

Research team

2.13%

Yes

2

-0.10

-0.77; 0.58

No

17

-0.29*

-0.49; -0.09

Number of types of educators

0.00%

One

11

-0.30*

-0.55; -0.04

Two

6

-0.41

-0.90; 0.07

Three or more

2

0.17

-0.34; 0.70

Peer provider

0.00%

Yes

7

-0.54

-0.93; -0.15*

No

13

0.29

-0.15; 0.74

Duration of the intervention (months)

8.4 (1.4)†

-0.02

-0.05; 0.02

Number of sessions

12.1 (2.1)†

-0.01

-0.02; 0.01

0.00%

Average duration of each session (hours)

1.5 (0.2)†

-0.01

-0.25; 0.23

0.00%

Total hours of intervention

21.9 (7.0)†

-0.01

-0.01; 0.01

0.00%

Intensity (number of hours/month)

4.6 (1.3)†

-0.01

-0.09; 0.07

1.60%