The demand for the synthesis of qualitative evidence is growing. Commissioners and others who use evidence summaries in decision making processes are realizing the need to include stakeholder perceptions and experiences in their decisions.
Qualitative evidence can be useful when exploring stakeholders’ perceptions and experiences related to acceptability, feasibility, and implementation.
Qualitative research aims to describe the social world, to understand people’s underlying reasons, opinions and motivations and to explain the social world by developing hypotheses, theories and models. Common methods include interviews, focus group discussions, observation, and document analysis. The aims of qualitative evidence synthesis are the same as those of primary qualitative research with aim being to synthesize across primary studies.
The process of conducting a qualitative evidence synthesis (QES) follow the same steps as conducting a systematic review of effect, including publishing a clearly written protocol. However, QES can be less linear in nature and more flexible in their design, adapting to the type of data that is identified. It is common to move back and forth between steps and take a more inductive approach to the project, learning as the review progresses.
- A clearly stated set of objectives with pre-defined eligibility criteria for studies (this can be flexible and change during the review process)
- An explicit, transparent methodology (not necessarily linear in nature)
- A well-defined, systematic search that attempts to identify studies that meet the eligibility criteria (does not need to find everything)
- A statement of the methodological limitations of the included studies
- A systematic and transparent method of data extraction, synthesis and presentation of the characteristics and findings of the included studies
Before starting the process of conducting a QES, the team should think through the following:
Is a QES appropriate for the question?
Is the question related to how people perceive or experience an event or intervention? Does it explore problems related to acceptability, feasibility, implementation, equity or similar?
Is a QES on this topic needed?
Do a quick scoping search to see if there is already a QES that answers the question.
What experience does the QES team need to have in order to be successful?
The lead author needs to have experience with conducting a QES and primary qualitative research. A minimum of one other team member must have experience conducting primary qualitative research.
No matter how a QES is conducted, clear and transparent reporting of the steps that were taken is necessary. In a QES it is very important to report both the data audit trail (how many studies at which stages through the PRISMA diagram) along with a decision audit trail. A decision audit trail explains the thought process and reasoning for the decisions taken during the QES. This is both at the protocol stage (for example, why a certain study selection or synthesis approach) and at the review stage (any changes to what was planned and why). Enhancing transparency in reporting the synthesis of qualitative research: ENTREQ is a guideline on this topic (1).