Methods for the thematic synthesis of qualitative research in systematic reviews

Article

Thomas, James and Harden, A. 2008. Methods for the thematic synthesis of qualitative research in systematic reviews. BMC Medical Research Methodology. 8 (45), pp. 1471-2288.
AuthorsThomas, James and Harden, A.
Abstract

Background
There is a growing recognition of the value of synthesising qualitative research in the evidence base in order to facilitate effective and appropriate health care. In response to this, methods for undertaking these syntheses are currently being developed. Thematic analysis is a method that is often used to analyse data in primary qualitative research. This paper reports on the use of this type of analysis in systematic reviews to bring together and integrate the findings of multiple qualitative studies.
Methods
We describe thematic synthesis, outline several steps for its conduct and illustrate the process and outcome of this approach using a completed review of health promotion research. Thematic synthesis has three stages: the coding of text 'line-by-line'; the development of 'descriptive themes'; and the generation of 'analytical themes'. While the development of descriptive themes remains 'close' to the primary studies, the analytical themes represent a stage of interpretation whereby the reviewers 'go beyond' the primary studies and generate new interpretive constructs, explanations or hypotheses. The use of computer software can facilitate this method of synthesis; detailed guidance is given on how this can be achieved.
Results
We used thematic synthesis to combine the studies of children's views and identified key themes to explore in the intervention studies. Most interventions were based in school and often combined learning about health benefits with 'hands-on' experience. The studies of children's views suggested that fruit and vegetables should be treated in different ways, and that messages should not focus on health warnings. Interventions that were in line with these suggestions tended to be more effective. Thematic synthesis enabled us to stay 'close' to the results of the primary studies, synthesising them in a transparent way, and facilitating the explicit production of new concepts and hypotheses.
Conclusion
We compare thematic synthesis to other methods for the synthesis of qualitative research, discussing issues of context and rigour. Thematic synthesis is presented as a tried and tested method that preserves an explicit and transparent link between conclusions and the text of primary studies; as such it preserves principles that have traditionally been important to systematic reviewing.

Keywordssystematic reviews; research methods; qualitative research; thematic synthesis
JournalBMC Medical Research Methodology
Journal citation8 (45), pp. 1471-2288
Year2008
Publisher's version
License
CC BY-ND
Web address (URL)http://dx.doi.org/doi:10.1186/1471-2288-8-45
http://hdl.handle.net/10552/1635
Publication dates
Print10 Jul 2008
Publication process dates
Deposited04 Jul 2012
Additional information

Citation:
Thomas, J. and Harden, A. (2008), 'Methods for the thematic synthesis of qualitative research in systematic reviews', BMC Medical Research Methodology, 8:45, doi:10.1186/1471-2288-8-45.

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