Table 2

Summary of common methodologies for the synthesis of qualitative health research*
Methodology Critical interpretive synthesis Grounded theory synthesis Meta-ethnography Meta-study Thematic synthesis
Key seminal methodology references Dixon-woods et al. 2006 [4] Kearney 2001 [23], Eaves 2001 [22] Noblit and Hare 1988 [11], Britten et al. 2002 [2] Paterson et al. 2001 [24] Thomas and Harden 2008 [12]
Philosophical positioning** Subjective idealism – no single shared reality independent of multiple alterative human constructions Objective idealism – a world of collectively shared understandings exists Objective idealism – a world of collectively shared understandings exists Subjective idealism – no single shared reality independent of multiple alterative human constructions Critical realism – knowledge of reality is medicated by one’s beliefs and perspectives
Literature search Theoretical sampling Theoretical sampling Non-specified Not-specified Systematic, comprehensive
Quality appraisal The degree to which the research findings can inform theory development Implicit judgement about the context, quality and usefulness of the study Judgement based on relevance; CASP Focuses on rigour and the epistemological soundness of the research methods Criteria related to aims, context, rationale, methods and findings, reliability, validity, appropriateness of methods for ensuring findings are grounded in participant perspectives
Analysis techniques and concepts · Concurrent iteration of the research questions · Concurrent data collection and analysis · Reciprocal translational analysis (translation of concepts from individual studies – 1st/2nd order constructs) · Analyse findings – meta-data-analysis · Line by line coding of text from primary studies
· Extract data and summarise papers · Theory is derived inductively from the data · Refutational synthesis (explore and explain contradictions between studies – 1st/2nd order constructs) · Analyse methods – meta-method) · Free codes organised into descriptive themes
· Define and apply codes · Constant comparison of data · Lines of argument (grounded theorising based on synthesising translations) · Analyse theory – meta-theory · Further interpretation to develop analytical themes
· Develop a critique, generate themes · Bring together all three components of the analysis
Synthesis output · New theoretical conceptualisation – synthetic construct · Generation of a new, higher-level grounded theory · New insights – 3rd order constructs · Account for differences in research findings · Analytical themes that offer a new interpretation that goes beyond the primary studies
· New interpretation of phenomena studied
Topic areas and study references Access to healthcare by vulnerable groups [4], pain management [26] Domestic violence [23], caregiving [22] Medicine-taking [3], patients’ help-seeking experiences in cancer presentation [6], palliative care [27] Chronic illness experience [14], influences on shared decisions making [15], adolescent health [16] Children’s experiences of health eating [12], chronic kidney disease [28], people’s understanding of cancer risk [29], organ transplantation [7], patient-physician relationships [30]

*This is not a complete list of methodologies as methodologies for the synthesis of qualitative health research are wide ranging; **Adapted from Barnett-Page and Thomas [1] and Spencer et al. [31]. References selected to reflect a range of topic areas in health research.

Tong et al.

Tong et al. BMC Medical Research Methodology 2012 12:181   doi:10.1186/1471-2288-12-181

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