Table 1.

List of criteria used to assess methodological quality and average score across studies.

Item	Criteria	Meana
1	Explicit theoretical framework	1.5
2	Statement of aims/objectives in main body of report	3.0
3	Clear description of research setting	2.1
4	Evidence of sample size considered in terms of analysis	1.5
5	Representative sample of target group of a reasonable size	1.3
6	Description of procedure for data collection	2.2
7	Rationale for choice of data collection tool(s)	1.8
8	Detailed recruitment data	2.2
9	Statistical assessment of reliability and validity of measurement tool(s) (quantitative only)	1.5
10	Fit between stated research question and method of data collection (quantitative only)	2.5
11	Fit between stated research question and format and content of data collection tool, for example, interview schedule (qualitative only)	1.9
12	Fit between research question and method of analysis (quantitative only)	2.5
13	Good justification for analytic method selected	1.2
14	Assessment of reliability of analytic process (qualitative only)	0
15	Evidence of user involvement in design	0.4
16	Strengths and limitations critically discussed	2.2

^aScores can range from 0 (not at all) to 3 (complete).