“What the Meta Is Going on?” A Scoping Review of the Different Approaches to Qualitative Synthesis

Andrew Soundy

doi:10.20944/preprints202510.1715.v1

Submitted:

21 October 2025

Posted:

22 October 2025

You are already at the latest version

Abstract

Background: There is a proliferation of terms that are used to define and describe qualitative methods of review synthesis. These terms can make understanding which approach to use difficult and the ability to generate operational clarity challenging. Further research is required that exams and maps the terms and approaches to synthesis. Objective: This scoping review aims to map the landscape of qualitative synthesis methods, evaluate the ability to operationalise named methods, and explore their philosophical foundations and methodological associations. Methods: Following PRISMA-ScR guidelines a scoping review was undertaken. A comprehensive search was conducted across multiple databases and grey literature sources. Articles were included that examined a methodological approach to qualitative synthesis. Data extraction and charting focused on synthesis type, frameworks, philosophical alignment, and operational guidance. Results: Fifty-one articles were identified and within these twenty-eight distinct syntheses approaches were identified. Meta-ethnography, meta-synthesis, grounded theory synthesis, and thematic synthesis being the most frequently cited. The ten most frequently identified approaches for synthesis are examined. A subset of these approaches were found to be the most operationalizable, including meta-ethnography, meta-narrative, and aggregative synthesis. Conclusion: The review highlights significant terminological and methodological fragmentation in qualitative synthesis. It underscores the need for clearer guidance, standardised terminology, and stronger links between synthesis methods and philosophical traditions. A decision tree and operationalisation matrix are proposed to support researchers in selecting appropriate synthesis approaches.

Keywords:

qualitative

;

review

;

meta-synthesis

;

grounded theory

;

narrative

;

synthesis

;

Subject:

Social Sciences - Other

Introduction

Qualitative evidence synthesis has become an essential component of evidence-based practice, particularly in health and social sciences, where understanding lived experiences, perceptions, and contextual factors is critical. While searching for qualitative studies is a foundational step in any synthesis, and appraisal of study quality is variably applied depending on philosophical stance and review purpose, the process of synthesis itself remains the most conceptually challenging and least standardized aspect of qualitative reviews. Currently there is an abundance of terms used to describe the synthesis process for instance, the term meta is accompanied by a high number of variations illustrating different synthesis approaches. This includes, but is not limited to, Meta-ethnography (Noblit and Hare, 1988), Meta-study (Paterson et al., 2001), Meta-narrative (Greenhalgh et al., 2005), Meta-aggregation (Bergdahl, 2019), and meta-interpretation (Weed, 2008). The term synthesis faces similar problems in terms of the sheer number of terms used in academic literature. For instance, the following terms have been identified describing approaches to synthesis including interpretive synthesis (Dixon-Woods et al., 2006), aggregative synthesis (Habersang and Reihlen, 2024), narrative synthesis (Popay et al., 2006), textual narrative synthesis (Lucas et al., 2006) and translation synthesis (Hoon, 2013).

Compared to empirical methods for synthesis, review-based approaches are often not linked closely and clearly linked to accompanying methodologies or philosophies. For instance, thematic analysis could be used within a study situated within a subtle realist world view and using interpretive hermeneutic phenomenology, alternatively, social constructivist grounded theory is clearly associated with pragmatism (Charmaz, 2017) and has very specific clear steps and considerations for analysis. Further empirical approaches could be named as such. The important point from this is that empirical approaches are easily operationalizable by knowing a methodology and philosophy, whereas the development of review synthesis approaches do not always appear to be. The inability to link methodology with synthesis approaches consistently means there is a greater need to understand the philosophical foundation of the synthesis approach to ensure the product of synthesis is what is intended by the approach. Recently, Soundy and Heneghan (2023) identify an approach which combines an empirical method of analysis (social constructivist grounded theory) with a well-established review technique (meta-ethnography) which may be one way of answering this problem and retaining or honouring key analytical strategies. However, the extent to which this problem is considered and identified in past reviews on synthesis approaches (e.g., Barrnett-Page and Thomas, 2009) is limited. A review that examines the underlying philosophical considerations to the meta-synthesis approach would be useful to allow scholars to establish these links and ensure a higher standard of practice for reviewing.

Given the above, it is possible that reviewers of qualitative research are confused by an extremely high number of terms which don’t necessarily clearly fit with a methodology or philosophy. In addition to this, there appear to be several articles that talk across synthesis techniques but, in themselves, may not provide enough guidance to enable the different named approaches to be operationalised. For instance, Hannes and Macaitis (2012), Nye (2016) do an excellent job of introducing approaches but the ability to operationalise each may be limited by what literature is available. A previous scoping review by Tricco et al. (2016) highlighted that many synthesis methods described in the literature were difficult to operationalise. A more recent scoping review by Perlman et al (2025) identifies an excellent consideration to some of the processes however, the details considered around the synthesis methods are lacking. This lack of clarity around methods of synthesis poses challenges for researchers attempting to apply these methods rigorously and transparently. Given this, it is important that an understanding of the aims of research that details different approaches is better understood.

Due to the proliferation of new synthesis techniques, there is a need to revisit and update the landscape of qualitative synthesis approaches with a special focus on which techniques may be possible to operationalise. This scoping review aims to identify and map the range of qualitative synthesis methods currently described in the literature. Identify those which could be operationalised and explore the approaches for association to methodology as well as philosophical foundations that underpin these approaches.

Methods

Design

A scoping review methodology was selected following the framework proposed by PRISMA (Tricco et al., 2018). This design is appropriate for mapping key concepts, identifying gaps, and clarifying definitions in complex and heterogeneous fields.

Eligibility Criteria

The eligibility criteria is based of the acronym PCC.

Population

Qualitative synthesis articles that haven been written and published by academics interested in synthesis methodology and produce articles related to synthesis.

Concept

Articles that identify a methodological approach to conducting qualitative synthesis and identify some consideration towards the steps involved in that approach. Any type of qualitative approach was acceptable including variations that may be associated with different methodologies or philosophical positions. Approaches which include the analysis of case studies were included. Worked examples of the synthesis procedures where during the process of analysis it was identified that that procedure was commonly understood and recognized and could be operationalised as an approach.

Chapters and books were excluded due to the ability to access all books and the prevalence of articles that covered the topic. Handbooks or commissioned reports which refer to articles when identifying synthesis and do not produce their own version of synthesis were excluded. Articles that identify an analysis approach designed for empirical studies. For instance, content analysis articles or thematic analysis articles would only be included if specifically designated for the purpose of being included as a step in a qualitative literature review. Quantitative meta-analyses or mixed-methods reviews without a distinct qualitative synthesis component were excluded.

Context

Only English language studies were included. Publications from any discipline, provided they focus on synthesizing qualitative data. Where multiple versions of the same article or approach exist by the same authors, only one of those articles was included. This was to avoid duplication and repetition, for instance, multiple references to the emerge guidelines were excluded, and one was selected to represent the approach.

Information Sources and Search Strategy

A comprehensive search was conducted across five electronic databases including MEDLINE, CINAHL, PsycINFO, Scopus, and Web of Science. The first 30 pages of electronic search engines GoogleScholar and ScienceDirect were searched. Grey literature and reference lists of included studies were also screened using ProQuest and GreyMatters. Search terms for electronic databases included combinations of: “qualitative synthesis” or “realist synthesis” “meta-ethnography” or “synthesis” or “meta-synthesis” or “framework synthesis” or “descriptive synthesis” or “narrative synthesis” or “critical interpretive synthesis” or “meta interpretation” or “grounded theory synthesis” AND “review” or “overview” or “methods” AND “qualitative” or “framework” or “approach”. A key and critical stages of citation chasing of included articles occurred to further elaborate and consider approaches identified.

Selection Process for Sources of Evidence

Titles and abstracts were screened by the study author. Covidence was used to assist the storage of identified texts and allow assessment of inclusion criteria to occur with two reviewers. Full texts were retrieved for potentially relevant studies and assessed against inclusion criteria. Discrepancies were resolved through discussion or consultation with a a third reviewer.

Data Extraction

For any included study the author developed a standardized data extraction form which captured the following sections of information including; name of author, year, aim of paper, type of synthesis method used.

Analysis

Descriptive statistics were used to summarize the frequency and distribution of synthesis methods. Graphs were used to document the frequency of terms identified to describe synthesis. Summary aims of articles were aggregated for the most common aims with descriptive statistics added. The definition of terms was developed by aggregating study definitions. Further detailed descriptive analysis was undertaken for the most common 10 approaches to synthesis mentioned this included identifying study originators or earliest reference from results, if frameworks were used, the philosophical foundation (e.g., interpretivist, constructivist) of the approach, identification of synthesis approaches used to create operational guidance, examples of application.

Results

Search Output

A total of 806 articles was identified, of which 51 were selected (Barnett-Page and Thomas, 2009; Bergdahl, 2019; Booth et al., 2024; Britten et al., 2002; Cahill et al., 2018; Carroll et al., 2013a; Chen and Boore, 2009; Dixon-Woods et al., 2005; 2006; Eaves, 2001; Evans and Pearson, 2001; Fendt, 2025; Finfgeld-Connett, 2013; Finlayson and Dixon, 2008; Flemming and Noyes, 2021; France et al., 2019; Gewurtz et al., 2008; Habersang-Reihlen, 2024; Hannes and Macaitis, 2012; Hoon, 2013; Hossler and Scalese-Love, 1989; Jensen and Allen, 1996; Lachal et al., 2017; Larsson, 1993; Leary and Walker, 2018; Levitt, 2018; Lockwood et al., 2015; Mohammed et al., 2016; Moser and Korstjensc 2023; Noah, 2017; Nye, 2016; Otte-Trojel et al., 2016; Pawson, 2002; Petticrew et al., 2014; Popay et al., 2006; Schick-Makaroff et al., 2015; Snilstveit et al., 2012; Soundy 2024; Suering and Gold, 2011; Timulak, 2009; Timulak and McElvaney, 2013; Walsh and Downe, 2005; Weed, 2008; Whittemore et al., 2014; Wolfswinkel et al., 2011; Wong et al., 2014; Xu, 2008; yin and Heald, 1975; Zimmer, 2006) . Figure 1 provides the PRISMA flow diagram.

Charting the Data and Synthesis

Of the included studies, the UK and the USA had produced the most work centered around qualitative synthesis. This is identified as follows UK: 19, USA: 11, Canada: 4, Australia: 3, Germany: 3, France: 2, Ireland: 2, Netherlands: 2, Norway: 1, Taiwan: 1, Belgium: 1, Sweden: 1, Denmark: 1. In addition to this, most of the research was published between 2006 and 2018 when around 3.5 papers/year were produced. Between 1975-2000 there was less than one/year and the highest year of production for papers was 2016 when 7 were produced.

The main aims of the articles included can be considered in Table 1. The two most common aims mentioned were; (a) to develop an innovative method and (b) to provide an overview of approaches. Guidance and instruction, identification of specific approaches and conceptual discussions appeared less see Table 1. Figure 1 identifies the frequency of the different types of review names used. Across the 51 papers 28 types of qualitative synthesis were named. Ten of these approaches used different or varied the name used to describe the synthesis approach. Across these 28 types of synthesis, the types of synthesis are considered in total across all papers 134 times, this includes articles that review many approaches to articles that just consider one named approach. The most frequently mentioned type of synthesis was as follows: Meta-ethnography 22, Meta-synthesis or qualitative interpretive meta-synthesis included 15, grounded theory or grounded meta-theory 11 and thematic synthesis, thematic analysis or thematic summaries 9, framework synthesis or best fit framework synthesis 8, realist review, rapid realist review or realist synthesis 8. Figure 2 provides the full breakdown of the names of each approach and how many times they have been considered across the 51 papers.

The Top 10 Most Named Synthesis Approaches

The 10 most frequently identified methods of synthesis are summarized and presented in Table 2. The most developed approaches which both utilise one name for synthesis were meta-ethnography and meta-synthesis. Meta-ethnography which has two frameworks developed (France et al., 2019; Soundy, 2024) and illustrates a consistent use of steps for undertaking synthesis as well as specific terms used which have all been derived from the original text (Noblit and Hare, 1988). The meta-narrative approach also has a framework (Wong et al., 2013), as does aggregative synthesis (Lockwood et al., 2015) which in addition has been linked to the JBI reviewing guide (Porritt et al., 2024). Meta-synthesis had the most articles that identified stages of the approach, although these stages were not consistent but referenced a similar process. The other-named approaches identified most often articles which identified an indicator of steps involved in synthesis, although the extent and nature of detailed steps may be limited. Specific approaches were clearly identified as producing results that could identify themes these included traditional meta-ethnography, thematic synthesis, framework synthesis, aggregative synthesis and meta study. Some approaches were identified as theory generating as an outcome these included meta grounded theory, social constructivist meta-ethnography, and critical interpretivist synthesis.

Table 3 identifies the philosophical assumptions of each approach as well as indicating specific findings about the approaches. For instance, the most observable finding is that aggregative approaches are limited to aggregative synthesis, some types of grounded theory and framework synthesis. However, the majority as associated with interpretive approaches. It is important to locate the ontology and epistemology of approaches especially when considering the product of the synthesis and what the synthesis is attempting to honor. Inductive theory building appears central to meta-synthesis, meta ethnography, grounded theory and critical interpretivist synthesis. Whereas, pluralism and historical context and reflexivity are important to other approaches like meta-narrative, realist synthesis or meta-study.

Tools which aid the ability to operationalise the approach

The above synthesis has provided the opportunity to consider tools which may aid choices around which synthesis technique to use. Table 4 provides an opertionalisation matrix which provides a summary of the above findings. Figure 3 provides a decision aid tool for researchers considering which approach may be most useful

Discussion

This scoping review mapped the landscape of qualitative synthesis approaches, revealing a complex and often fragmented field. Given the number of papers identified it is important to note the limited number that provide sufficient details to allow a reviewer to operationalise the approach. The findings underscore several critical issues that merit further discussion, particularly around the operationalisation, philosophical foundations, and terminological clarity of synthesis methods.

Proliferation and Confusion of Terminology

One of the most striking findings is the sheer volume and variation of terms used to describe qualitative synthesis approaches. Across 51 papers, 28 distinct synthesis types were named, with many approaches being referred to by multiple or inconsistent labels. This terminological diversity adds layers of confusion for researchers, especially those new to qualitative synthesis, and complicates efforts to compare, replicate, or apply methods consistently. The lack of standardised naming conventions may hinder methodological transparency and reduce the accessibility of synthesis techniques. Research has begun to categorising synthesis to types for instance aggregative and interpretive types provides a useful focus (e.g., Drisko, 2020). However, further understanding from the current results around the philosophical basis of approaches is essential.

Operationalisation: A Key Challenge

While many synthesis approaches are conceptually rich, only a subset appear to be sufficiently developed to allow for practical application. Notably, meta-ethnography, meta-synthesis, meta-narrative, and aggregative synthesis were identified as more easily operationalisable due to the presence of frameworks, agreed stages, and detailed guidance. Meta-ethnography, for example, benefits from two established frameworks (France et al., 2019; Soundy, 2024) and a consistent set of analytical steps derived from Noblit and Hare (1988). In contrast, other approaches such as grounded theory synthesis or thematic synthesis often lack unified guidance, making their application more variable and dependent on reviewer interpretation.

This disparity in operational clarity reflects a broader issue: many synthesis methods are introduced or discussed conceptually but lack sufficient detail to be implemented rigorously. This aligns with previous reviews (e.g., Tricco et al., 2016; Perlman et al., 2025), which noted the difficulty of operationalising synthesis techniques due to limited methodological elaboration.

Philosophical Foundations: Interpretive versus Aggregative Approaches

The review highlights a predominance of interpretive synthesis approaches, with fewer aggregative methods represented. Understanding the philosophical roots of each approach is essential, as these foundations influence not only the synthesis process but also the nature of the findings produced. For instance, interpretive methods such as meta-synthesis and critical interpretivist synthesis are grounded in constructivist and interpretivist epistemologies, aiming to generate new theoretical insights through reflexive and inductive processes. In contrast, aggregative synthesis, grounded in realism and pragmatism, seeks to summarise findings for practical application, often avoiding reinterpretation.

This philosophical divergence has practical implications. Interpretive approaches may lead to multiple syntheses on the same topic, each offering nuanced but potentially overlapping insights. As noted in your comment, this raises concerns about redundancy and the risk of rewording existing knowledge rather than generating genuinely novel understandings.

Temporal and Geographic Trends

Most synthesis development occurred between 2006 and 2018, with the UK and USA leading in publication output. This suggests a period of methodological innovation and consolidation, possibly driven by increased interest in qualitative evidence synthesis within health and social sciences. However, the decline in recent publications may indicate either saturation or a shift toward refining existing methods rather than introducing new ones.

Implications for Reviewers and Methodologists

Given the findings from the current scoping review, several implications emerge:

Clearer guidance is needed for reviewers to select and apply synthesis methods appropriately. This includes better articulation of steps, philosophical underpinnings, and expected outcomes. A starting point for this could be the tables identified within the results
Methodological transparency should be prioritised in future publications, with authors encouraged to provide worked examples and frameworks.
Terminological standardisation could help reduce confusion and improve the comparability of synthesis approaches.
Training and education in qualitative synthesis should emphasise the link between philosophical foundations and methodological choices, helping researchers navigate the interpretive-aggregative spectrum more effectively.

Future Directions

Future research should aim to:

Develop consensus frameworks for under-defined synthesis approaches.
Explore the epistemological implications of repeated interpretive syntheses on the same topic.
Investigate how synthesis methods can be better linked to empirical methodologies, potentially enhancing coherence and applicability.
Examine the impact of philosophical alignment on the quality and utility of synthesis findings, especially in applied fields like health policy and rehabilitation.

Limitations

This review did not include books or handbooks that could capture relevant material. It is possible that this review has not captured all types of synthesis approaches. The review is limited by its focus on synthesis approaches and key words used and not the fuller or broader steps of review. Only the most elaborate papers from a researcher or research group on a synthesis approach was included. Because not every synthesis paper from each author was included there may be some limitation in findings.

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Figure 1. The PRISMA flow diagram.

Figure 2. A summary of the named techniques of synthesis.

Figure 3. A decision tree for selecting qualitative synthesis approaches.

Table 1. Detailed Summary of Common Aims in the Scoping Review.

Aim Category	Description	Example
1. Methodological development / innovation (18 papers)	These papers aimed to develop, refine, or introduce new synthesis methods or frameworks. They often proposed novel techniques, adapted existing ones, or created hybrid approaches to improve the rigour, flexibility, or applicability of synthesis.	“To introduce a synthesised technique for using grounded theory in nursing research”
2. Overview or review of existing methods (15 papers)	These papers provided comprehensive overviews, comparisons, or critiques of existing synthesis methods. Their goal was to map the landscape of available approaches and help researchers understand the strengths, limitations, and contexts of use.	“To bring together and review the full range of methods of synthesis that are available”
3. Guidance or instruction for applying methods (10 papers)	These papers offered practical guidance, frameworks, or step-by-step instructions for conducting synthesis. They were often aimed at helping researchers apply methods correctly and consistently.	“To provide clear methodological instructions to assist others in applying these synthesis methods”
4. Exploration of specific synthesis techniques (8 papers)	These focused on particular synthesis types (e.g., meta-ethnography, thematic synthesis, narrative synthesis), often elaborating on their processes, benefits, and challenges.	“To demonstrate the benefits of applying meta ethnography to the synthesis of qualitative research”
5. Conceptual or epistemological discussion (6 papers)	These papers explored the theoretical foundations, philosophical assumptions, or epistemological implications of synthesis. They often questioned the validity or coherence of combining certain methods or paradigms.	“To discuss whether this meta-aggregation form of research has a sound epistemological foundation and should be considered a viable form of meta-synthesis”
6. Application to case studies or specific fields (5 papers)	These papers applied synthesis methods to specific domains (e.g., occupational therapy, psychiatry, supply chain management) or types of data (e.g., case studies), often to demonstrate feasibility or generate domain-specific insights.	“Provide the research design of a meta-synthesis of qualitative case studies”

Table 2. Identifying the top 10 most frequently identified approaches to synthesis.

Approach	What is an aggregated definition across studies of the approach	Identified sub-types of the approach and key differences?	Are there agreed stages and what are the processes	Originator or earliest reference identified	Framework that accompanies the approach & articles with detailed description
Meta-ethnography	Meta-ethnography is an interpretive method for synthesizing qualitative studies. It involves the translation of concepts and metaphors across studies to build explanatory theory, new conceptual understandings, and higher-order interpretations. The method goes beyond summarizing findings by merging and combining insights to form a line-of-argument synthesis.	Social constructivist meta-ethnography (Soundy, 2024) which assumes a social constructivist philosophical position and brings grounded literature theory from the work of Charmaz. This approach emphasizes interpretation and conceptual translation, aiming to construct new theoretical understandings	Agreed stages Yes Key stages Reciprocal Translational Analysis (RTA): Aligns concepts across studies. Refutational Synthesis: Explores contradictions. Lines-of-Argument (LOA): Builds a coherent whole from parts.	Noblit and Hare (1988)	Frameworks: EMERGE (France et al., 2019). Social Constructivist Framework (Soundy, 2024) Articles Britten et al (2002), Cahill et al (2018), France et al (2016;2019), Mohammad et al (2016), Moser and Korstjensc (2023), Soundy (2024), Whittmore et al (2014)
Grounded Theory or Meta Grounded theory	Grounded theory synthesis is an inductive, iterative approach that integrates constant comparison, theoretical sampling, and structured coding to develop higher-level, abstract theories. It draws from multiple traditions including Glaserian, Straussian, and Constructivist streams, emphasizing conceptual development, memoing, and rigorous analysis of qualitative data.	Social constructivist meta-ethnography (Soundy, 2024) which assumes a social constructivist philosophical position and brings grounded literature theory from the work of Charmaz. This approach is highly iterative and inductive, focusing on theory generation from raw data.	Agreed stages No. One of the problems is which type of grounded theory is used to represent the approach. Key stages Coding (line-by-line, axial, selective, substantive) Constant comparison, memoing, theoretical sampling Category and concept development Abductive reasoning and explanatory frameworks	Eaves (2001)	Frameworks Social Constructivist Framework (Soundy, 2024) Articles Chen and Boore (2009), Eaves (2001), Soundy (2024), Wolfswinkel et al (2013)
Thematic Synthesis or Thematic Analysis or Thematic Summaries	Thematic synthesis is a flexible and interpretative method that involves identifying, analyzing, and reporting themes across qualitative studies. It includes line-by-line coding, the development of descriptive and analytical themes, and aims to generate new insights, hypotheses, and conceptual frameworks.	No. This approach balances data-driven and theory-driven synthesis, moving from descriptive to interpretive insights.	Agreed stages Most studies identify Thomas and Hardin (2008) and there three step approach. Step one coding text using line-by-line coding. Key stages Line-by-line coding Descriptive theme development Analytical theme generation Pattern identification, categorization, and hypothesis development	Dixon-Woods et al (2005)	Framework No framework. Articles Flemming and Noyes (2021), Thomas and Hardin (2008)
Meta-synthesis or qualitative interpretive meta-synthesis	Meta-synthesis is an interpretive and systematic approach to integrating findings from multiple qualitative studies. It aims to generate new theoretical insights, holistic understanding, and conceptual interpretations of a phenomenon. Unlike meta-analysis, it focuses on synthesizing textual data and translating qualitative accounts to produce higher-level explanations and generalizations.	No. But many identify specific steps. This approach emphasizes holistic integration and theoretical insight, respecting dissonance and preserving original voices.	Agreed stages No but many detailed approaches are available. Key stages Primary analysis and within-case coding Cross-case synthesis and translation Theory development and meta-theory Narrative presentation	Jensen and Allen (1996) identified a 6 stage process	Framework No framework Articles: Gewurtz et al (2008) identify a 5 stage process Hoon (2013) identify an 8 stage process Jensen and Allen (1996) identify a 6 stage process Leary and Walker (2018) identify an 11 stage process Lachal et al (2017) identify a 6 stage process Walsh and Downe (2005) identify a 7 stage process Zimmer (2006) identifies a 6 stage process Xu (2008) identifies a 7 stage process Noah (2017) identify a 7 stage process
Framework Synthesis or Best fit Framework Synthesis	A structured and deductive synthesis approach that uses a pre-existing or tentative framework to organize, interpret, and refine qualitative data and findings. It supports theory development, policy relevance, and rapid synthesis by mapping key dimensions and iteratively adapting the framework.	No but some have different steps. This is a deductive approach, using pre-existing frameworks to guide synthesis and interpretation	Agreed stages No. There are limited articles that provide information. Key stages Framework identification Data extraction and coding Theme identification and model development Recognition of emerging concepts	Barnett-Page and Thomas (2009)	Framework None. Articles Flemming and Noyes (2021) Caroll (2013)
Realist Synthesis or Realist Review or Rapid Realist Review	A realist review is a theory-driven, systematic approach that seeks to understand how and why complex interventions work, for whom, and under what circumstances. It focuses on identifying context-mechanism-outcome (CMO) configurations to explain causal processes and refine programme theories.	No but some have established steps. This approach is theory-driven, aiming to explain how and why interventions work in specific contexts.	Agreed stages No but some have detailed approaches. Key stages Context-Mechanism-Outcome (CMO) configurations Programme theory development and refinement Evidence synthesis and stakeholder engagement	Pawson (2002)	Framework: None Articles: Rapid Realist Synthesis: Moser and Korstjensc (2023). Realist Synthesis: Otte-Trojet et al (2016), Pawson (2002), Wong et al (2014)
Meta-Study	Meta-study is a multifaceted and highly systematic research approach designed to analyse and synthesize qualitative research. It involves three core components: Meta-data analysis: Examining the findings across studies to identify patterns, themes, and insights. Meta-method: Analysing the methodologies used in the original studies to understand their influence on outcomes. Meta-theory: Investigating the theoretical frameworks that underpin the research to explore how they shape interpretation.	No. All references linked back to a book by Paterson et al (2001) This is a multi-layered synthesis, combining empirical, methodological, and theoretical insights.	Agreed stages Yes. The agreed stages are based on work by Paterson et al (2001) Key stages Meta-data, meta-method, and meta-theory analysis Integration into mid-range theory	Paterson et al (2001)	Framework: None Articles Paterson et al (2001)
Meta-Narrative	A meta-narrative review is a synthesis technique designed to make sense of complex and contested topics that have been studied across multiple research traditions, paradigms, or epistemologies. Drawing on Kuhn’s theory of scientific revolutions, it treats each research tradition as a distinct storyline or “meta-narrative,” analyzing how conceptualizations, theories, methods, and assumptions have evolved over time.	No. Work links back to Greenhalgh’s research (Greenhalgh et al., 2005) This approach synthesizes diverse research traditions, focusing on historical and epistemological evolution.	Agreed stages Yes by Wong et al (2013) Key stages Iterative scoping, mapping traditions Narrative construction, comparative analysis Meta-narrative synthesis, principle-guided synthesis	Greenhalgh et al (2005)	Ramses guidelines (Wong et al., 2014) Articles Hammick et al (2007)
Critical Interpretivist Synthesis	Critical Interpretivist Synthesis is a theory-generating, iterative methodology that adapts and extends meta-ethnography and grounded theory to critically engage with qualitative literature. It emphasizes the construction of synthetic arguments and theoretical frameworks through a reflexive process	No. Work is linked back to Dixon-Woods et al (2006) This approach emphasizes interpretive depth and critical engagement with literature.	Agreed stages Yes the steps should link to Dixon-Wood et al. (2006) Key stages Reflexive coding and categorization Synthetic construct development Theoretical framework construction Critical narrative production	Dixon-Woods et al (2006)	Framework None Articles Dixon-Woods et al (2006)
Aggregative Synthesis	Aggregative synthesis is a pragmatic method of qualitative synthesis that focuses on summarizing findings under predefined categories and grouping similar results across studies to identify common themes or patterns. Rather than aiming for deep theoretical abstraction, it seeks to present findings as they were intended by the original authors, avoiding reinterpretation. While it involves some interpretive work, its emphasis is on accuracy, reliability, and producing actionable recommendations for practice and policy.	No. But the method can be confused with a quantitative version (Dixon-wood et al., 2006) This is a pragmatic and structured approach, focused on actionable findings rather than deep theoretical abstraction.	Agreed stages Yes. Lockwood et al (2015) provided a clear approach. Key stages Data extraction and categorization Theme grouping and synthesis Practice recommendations Confidence assessment (CONQual)	Estabrooks et al (1994)	Framework JBI Handbook Porritt et al (2024) Articles Lockwood et al (2015)

Table 3. Philosophical Foundations of Synthesis Approaches.

Approach	Philosophical Foundation	Worked example of the approach
Meta-ethnography Social constructivistMeta-ethnography	Meta-ethnography originally was identified a relativist ontology and interpretivist epistemology (France et al., 2019; Noblit and Hare, 1988). Social constructivist meta-ethnography assumes a pragmatist ontology and relativist epistemology (Mohajan & Mohajan, 2022).	Britten et al (2002) Sattar et al (2021) McMillan and Soundy (2025)
Grounded Theory / Meta Grounded Theory	Traditionally three main approaches exist by vary into how ontology. Glaserian grounded theory is situated as having a realist ontology and objective epistemology. Straussian grounded theory is associated with a relativist ontology and subjectivist epistemology and the Charmazian version of grounded theory is based on pragmatism (Soundy, 2025). Some authors do not identify within the text how the original approaches may influence the synthesis methods (Barnett-Page and Thomas, 2009; Dixon-Woods et al., 2005; Finlayson and Dixon, 2008; Hannes and Macaitis, 2012). Chen and Boore (2009) developed a synthesis approach which is based on all three methods. Eaves (2001) does something similar but adds in an additional author (Chesler).	Meta grounded theory example: Cooper et al (2012) or Eaves (2001). Formal grounded theory approach (Kearney, 2001). Reviewing linked to Glaser’s form of GT (after theory development): Berthelsen et al (2018). Social constructivist version McMillan and Soundy, (2025).
Thematic Synthesis / Analysis / Summaries	Thomas and Hardin (2008) do not specifically identify the terms ontology and epistemology. However, it is likely that the ontology is relativism or contextualism. They state qualitative research is “specific to a particular context, time and group of participants” and the epistemology is interpretivist as reviewers actively shape understanding.	Thomas and Hardin (2008) within their paper provide a worked example and later another example by Kavanagh et al (2011).
Meta-synthesis / Qualitative Interpretive Meta-synthesis	Ontology is identified as constructivist assuming that reality is socially constructed and context-dependent and epistemology is interpretivist and knowledge generated by the reviewer by conceptualization and interpretation (Chrastina, 2020)	Aguirre and Bolton (2014). Finfgeld-Connett (2010). Nye et al (2016).
Framework Synthesis / Best Fit Framework Synthesis	The ontology is likely subtle realist with the attempt to gain useable common findings. The epistemology is partially interpretivist but also structured and deductive and begins within an a priori framework (Carroll et al., 2013b).	Carroll et al. (2013a) Rapid best fit example Shaw et al (2020)
Realist Synthesis / Review / Rapid Realist Review	Ontology is realism and this include mechanism which are generative that cause outcomes observed. Epistemology is relativism but knowledge is situated in history and socially valid claim are made by critical engagement. Realist synthesis acknowledges that claims made may be more or less accurate of reality (Albert et al 2020)	Pawson et al. (2005); Wong et al. (2013)
Meta-Study	Constructivist ontology identifying socially constructed reality with contextual truths. A single reality is not sought rather multiple interpretations are considered. The epistemology is interpretivist emphasising constructed knowledge (Grass, 2024)	Rycroft-Malone et al (2012). Paterson et al (2001).
Meta-Narrative	Ontology is identified a constructivist philosophy and inspired by the work of Kuhn. The epistemology is interpretivist and pluralist. The generation of knowledge is generated by comparing and understanding how different research traditions investigate a topic therefore reflexivity, contestation and the history of knowledge is considered (Greenhalgh et al., 2013)	Greenhalgh et al. (2005)
Critical Interpretivist Synthesis	Ontology is identified as critical realist and constructivist as reality is assumed to be socially constructed however also theorised and critiqued. Epistemology is identified as interpretivist and critical as knowledge is constructed through inductive, reflexive and iterative processes so new knowledge is generated (Perlman et al., 2025)	Dixon-Woods et al. (2006). Multiple examples can be identified from Perlman et al (2025)
Aggregative Synthesis	Ontology of realism identifying that findings represented in qualitative studies provide a meaningful consideration and an epistemology of pragmatism valuing real world findings with a focus on what works. Pragmatism — focuses on summarizing findings to inform decision-making, often used in policy and practice contexts (Hannes and Lockwood, 2011).	Pearson et al. (2011)

Table 4. An operationalisation matrix.

Synthesis Approach	Ability to Operationalise	Specific Framework Available	Philosophical Alignment
Meta-Ethnography	High	Yes	Interpretivist / Social Constructivist
Meta-Narrative	High	Yes	Constructivist / Interpretivist / Pluralist
Aggregative synthesis	High	Yes (JBI)	Realist / Pragmatist
Meta-Synthesis	Medium	No	Constructivist / Interpretivist
Grounded Theory	Medium	Yes (varied)	Realist / Constructivist / Pragmatist
Thematic synthesis	Medium	No	Contextualist / Interpretivist
Framework synthesis	Medium	No	Subtle Realist / Deductive / Interpretivist
Realist Synthesis	Medium	Yes (RAMSES)	Realist / Relativist
Meta-Study	Medium	No	Constructivist / Interpretivist
Critical Interpretivist Synthesis	Medium	No	Critical Realist / Constructivist / Interpretivist

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