Presentation on theme: "Narrative Synthesis in Systematic Reviews"— Presentation transcript:
1Narrative Synthesis in Systematic Reviews An ESRC Research Methods Programme projectMark RodgersLisa Arai, Nicky Britten, Mark Petticrew, Jennie Popay, Helen Roberts, Amanda SowdenHelloQuick overview of our ESRC funded projectTo devise guidance on narrative synthesis in systematic reviews.
2Structure of the Presentation What is “narrative synthesis”?Where does narrative synthesis (NS) fit in a systematic review?Why do we need guidance?Developing a framework for NSBuilding on the frameworkStart with a quick overview
3What Is a “Narrative Synthesis”? NS are findings summarised and explained in wordsAs used here, NS refers to the approach adopted to bringing together the findings from studies included in a systematic reviewNo clear definition of NS“Not a meta-analysis”Can be alternative or complementary to MASo what is a narrative synthesis?Meta-analysis would be inappropriate where studies were too different from one another either statistically or clinically to combine using that method.Nevertheless, we still want to be able to combine the findings of multiple studies in one place.
4Where does it fit? ‘Typical’ systematic review process: Define review questionLiterature searchStudy selectionData extractionStudy appraisalSynthesisConclusions/recommendations
5Why Do We Need Guidance? NS lacks transparency NS lacks reproducibilityVariations in practiceNo coherent guidance currently existsWhy do we need guidance?Unlike meta-analysis, lacks transparency and reproducibility.Everybody does it a bit differently
6Developing guidance for NS Difficult (impossible?) to produce prescriptive guidance on the conduct of NSMost appropriate approach depends on contextA NS “toolkit” may be better than traditional “guidance”Requires a structureUnfortunately, cannot produce singular, prescriptive guidance.Part of the reason why so much variation exists in current approaches is that each synthesis has to be appropriate to the context in which it was conducted.
7A framework for NS An descriptive framework of the NS process: Developing a theoryDeveloping a preliminary synthesisExploring relationships in the dataAssessing the robustness of the synthesis
8Developing a theory“Theory of change” linking resources, activities, intermediate outcomes and ultimate goalsHow the intervention works, why and for whomHas implications for review question and inclusion criteria as well as interpretationConsider early in the review processCan be presented in narrative and/or diagrammatic form
9Developing a preliminary synthesis Initial description of the results of included studiesOrganise results to describe patterns, e.g. in:size/direction of effectsfactors/processes impacting on implementationqualityProduct of this process is preliminary and should be interrogated further
10Exploring relationships in the data Explore relationships:Between study characteristics and their findingsBetween the findings of different studiesExplore influence of heterogeneity:Variations in outcomes, methods, populations, interventions, settings etcTheory may help develop plausible explanations for observed differencesInvestigation of context partly dependent upon reporting of included studies
11Assessing the robustness of the synthesis Robustness of NS depends on two related elements:Methodological quality of included studies‘Trustworthiness’ of the synthesis productAvailability of key information in primary studiesOverall assessment of the strength of evidence available to support conclusions
12Building on the framework (1) Populated framework with range of “tools and techniques” (e.g. tabulation, idea webbing/conceptual mapping, transforming and translating data)Allow reviewer to select tools/techniques most appropriate to the data being synthesisedNot necessarily linear or sequential process – reviewers will move iteratively between elements
13Building on the framework (2) Conducted two ‘test’ NS of domestic smoke alarm promotion interventions: one effects, one implementationQualified success - the approach can be further developed and refinedWould benefit from application to a wider range of syntheses