Table 1.

Study data (n = 72).

	Effect
Ways of delivery and duration of encounter in minutes (n = 70)a	Yes	No
Individual interview, 10–20	7	4
Individual interview, 30–45	12	5
Individual interview, 60	26	6
Individual interview, 60–120	4	2
Group interviewb	3	0
Telephone interviewb	0	1
Number of encounters (n = 71)c	Yes	No
1	10	15
2	12	0
3	5	1
4	8	2
5	3	0
>5	13	2
Counsellor profession (n = 76)d	Yes	No
Psychologist	33	9
Doctor	19	4
Other health care provider (nurse, midwife, dietician)	5	6
Intervention period in months (n = 71)e	Yes	No
<3	4	11
3–5	8	3
6–11	10	3
12	16	3
12–24	5	3
>24	5	0
Measuring method (n = 116)f	Yes	No
Direct biological/clinical measures (e.g. HbA1c)	25	8
Direct utilisation of healthcare services (e.g. number of encounters)	8	3
Indirect measures (e.g. questionnaire)	53	19
Area of intervention (n = 72)	Yes	No
Diabetes/asthma	2	1
Smoking cessation	8	4
Weight-loss/physical activity	8	2
Alcohol abuse	23	5
Psychiatrics/addiction	12	7

^aTwo studies only described the intervention as an individual interview without describing an accurate length of the interview.

^bThe length of the group and telephone interviews was not described in the articles.

^cOne study only described the intervention as an individual interview without describing the number of counselling encounters.

^dFive studies involved encounters with several counsellors of different educational background, which is why the total number exceeds the total number of studies.

^eStudy did not describe the follow-up period.

^fIn some studies both direct and indirect measures were used, which is why the total number exceeds the total number of studies.