Table 2 Mean HbA1c Improvements across groups, study length and quality in Randomised Control Trials

Text messages

Rami 2006 [39]

9.1

9.2

0.1

9.3

8.85

-0.45*

6

12

Franklin 2006 [42]‡‡

10.0

9.2

-0.8*

10.1

10.3

0.2

9.8

10.1

0.3

12

19

Telephone support

Howells 2002 [44]

8.4

8.7†

0.3

8.9

9.5†

0.6*

8.5

8.8*

0.3

12

22

Nunn 2006 [46]

8.15

8.85

0.7*

8.32

8.82

0.5*

-

-

7

20

Novel electronic communication

Chase 2003 [40]

9.0

8.6

-0.4

8.9

8.6

-0.3

-

-

6

15

Farmer 2005 [41]

9.2

8.6

-0.6*

9.3

8.9

-0.4*

-

-

9

25

Cadario 2007 [48]

9.5

8.8

-0.7*

9.1

9.1‡

0

-

-

18

15

Gay 2006 [43]

9.22

9.12

-0.1

9.17

9.27

0.1

-

-

6

18

Marrero 1995 [45]

9.4

10

0.6*

9.9

10.3

0.4*

-

-

12

16

Rosenflack 1993 [47] **

10.3

8.9

-1.4*

9.3

9.3

0

9.8

9.6

-0.2

12

15