Integrating quantitative and qualitative evidence in systematic reviews: To pool or not to pool?

Article type
Authors
Lizarondo L1, Stern C1, Loveday H2, Salmond S3, Apostolo J4, Bath-Hextall F5, Carrier J6
1The Joanna Briggs Institute, University of Adelaide
2Richard Wells Research Centre, University of West London
3Rutgers School of Nursing
4Nursing School of Coimbra
5School of Health Sciences, University of Nottingham
6School of Healthcare Sciences, Cardiff University
Abstract
Background: Mixed-studies review, also known as mixed-methods review, mixed research synthesis or a systematic review integrating quantitative and qualitative studies, is becoming popular in health services research. This approach to systematic review draws upon the strengths of both quantitative and qualitative studies, and overcomes the issues associated with independent synthesis of one type of evidence alone. Currently, there is no consensus with regards to how such reviews should be conducted.

Objectives: The aim of the presentation is to describe the methodology of the Joanna Briggs Institute for undertaking a systematic review of quantitative and qualitative evidence.

Methods: The Joanna Briggs Institute organised a working group of seven experienced secondary researchers to develop guidance for mixed-studies review. Email correspondence, teleconferences and round table discussions were held to gather feedback and achieve consensus on the proposed methodology.

Results: The Institute has adopted a practical framework for synthesising evidence from quantitative, qualitative and mixed-methods studies. The methodology is drawn predominantly from Sandelowski’s approach to mixed-research synthesis with appropriate consideration of the body of literature on mixed-methods research and mixed-research synthesis. The methodology highlights the key elements to consider when undertaking mixed reviews and how these elements impact on the approach to synthesis. A set of examples to illustrate the different approaches to synthesis are provided.

Conclusions: Mixed-studies reviews allow a more comprehensive and richer understanding of the question of interest, and are particularly useful for understanding complex interventions or multi-level processes that are common in health quality improvement initiatives.