Background: There is considerable interest currently in including 'qualitative' studies in reviews but much uncertainty about how to do this and whether it is an approach which adds value. Together with other colleagues at the UK-based Evidence for Policy and Practice Information and Co-ordinating Centre, we have developed a set of methods to integrate 'qualitative' studies and trials in a single review [1]. A programme of new reviews offered an opportunity to test these methods further.

Objectives: To describe these methods in a series of reviews related to teenage pregnancy, parenthood and social exclusion. Our substantive question was 'What is known about interventions which target social exclusion to prevent unintended teenage pregnancy and support teenage parents'.

Methods: Exhaustive searches sought trials to examine intervention effects and 'qualitative' studies describing young people's perspectives and experiences ('views' studies). The quality of studies was assessed using criteria appropriate for each study type. Three types of syntheses were conducted:

1. statistical meta-analysis;
2. qualitative thematic; and
3. mixed methods.

Results: The meta-analyses examined intervention effects on teenage conceptions, educational qualifications, and employment status. For pregnancy prevention, the thematic analysis found that young people identified 'dislike of school', 'low expectations for the future', and 'unhappy childhoods' as important influences on teenage parenthood. The mixed methods synthesis identified whether interventions evaluated by trials met the needs of young people (e.g. interventions rarely addressed 'dislike of school' in the ways suggested by young people)

Conclusions: The utility of our methods for including 'qualitative' studies alongside trials was confirmed. 'Qualitative' studies added value for:

a. determining the appropriateness of interventions;
b. exploring heterogeneity in effects; and
c. identifying promising interventions to test.

These methods could be tried out in Cochrane Reviews.

Acknowledgements: Thanks to Helen Burchett and Mona Backhans for their work in the early stages of the reviews. The English Department of Health (DH) funded the reviews described in this paper. The views expressed are those of the authors and not necessarily those of the DH.

1. Thomas et al. (2004) Integrating qualitative research with trials in systematic reviews: an example from public health. BMJ 328: 1010-12.