Table 2 Methodology Quality Score (MQS; adapted from Gurman and Kniskern 1978; Stanton and Shadish 1997)

1

Controlled assignment to treatment conditions (random assignment, matching of total groups or controlled design, without randomization (2.5) matching in pairs)

5

2

Pre-post-measurement of change

5

3

Sample size N = 50-100 (0.5) N = 100-150 (1) N > 150 (1.5)

1.5

4

No contamination of major independent variables: Most important independent variable is valid, i.e., parental substance use proven (2), very likely (1), program implemented by professional staff (3)

5

5

Appropriate statistical analyses

1

6

Data collected via self-assessment and expert interviews

1

7

Follow-up in months 1–3 (0.5), 4–6 (1), 7–12 (1.5) 13–18 (2), 19–24 (2.5) >24 (3)

3

8

Evidence of treatment adherence: probably (0.5), certainly, as stated by the authors (1), verifiable (1.5)

1.5

9

Multiple change indices

1

10

Multiple vantage points for assessing outcome, multiple criterion measurement

1

11

Quality of instruments reported

1

12

Simultaneous data collection for the control group; Non-simultaneous data collection for the control group (0.5)

1

13

Outcome assessment: Non-responder – improvement (0.5)Deterioration – improvement (1)

1

14

Therapist-investigator nonequivalence: examiners not involved in program delivery

1

15

Treatment dropouts / intent-to-treat analyses

1