Evidence synthesis aggregates all relevant information on a specific topic in order to draw well-informed, evidence-based decisions. It is an essential activity in recommending, providing and evaluating clinical care. If improperly done, however, evidence synthesis may neglect the perspectives and priorities of key stakeholders, including patients, their caregivers, and healthcare providers. This negligence can limit the acceptability, feasibility, and efficacy of an intervention.

One strategy to ensure that all relevant perspectives are included in a literature review is to perform qualitative evidence synthesis, sometimes called qualitative systematic review. In this process, findings are synthesised from several qualitative studies, which are primarily narrative accounts of stakeholders’ perspectives, attitudes, and experiences. Qualitative studies typically involve interviews, focus groups, and patient diaries, among other methods.

By combining findings from multiple qualitative studies, qualitative evidence synthesis delivers findings that are more robust and less prone to the methodological limitations that may undermine individual studies. Those limitations include study participants who do not fully represent the target population, or data collected or reported improperly, or incompletely, which therefore do not capture the full variety of perspectives and experiences. Qualitative evidence synthesis can also extend beyond individual studies by identifying patterns in the data, leading to the development of models and conceptual frameworks. For instance, a qualitative evidence synthesis could identify multiple barriers and facilitators to treatment adherence, which in turn may inform which strategies are more likely to be effective at promoting adherence in clinical settings. As another example, qualitative evidence synthesis can identify attitudes of all relevant stakeholders — including patients, their caregivers, and healthcare providers — towards a specific treatment, helping to streamline its implementation and ultimately make it more effective.

Qualitative evidence synthesis follows the same rigorous methodological procedures used in quantitative evidence synthesis. The first step is formulating a well-defined research question that identifies the key elements needed to inform decision making. The analyst must clearly define the participants, setting, health issues, interventions, and other key contextual details. Imprecision at this stage can prolong the search process and generate irrelevant evidence that does not lead to clear, actionable conclusions. Where qualitative evidence synthesis differs from its quantitative cousin is in the type of data: qualitative evidence is primarily text-based. As a result, analysts must extract and synthesise data using appropriate thematic or framework syntheses, or meta-ethnography.

What is the added value of qualitative evidence analysis?

The views, attitudes, and experiences of patients, healthcare professionals, and other stakeholders are essential for the development, implementation, and uptake of medical technologies. The central role that patients have in the development and implementation of new technologies is now well recognised by regulators, health technology assessment (HTA) agencies, and healthcare providers. All these groups highlight the importance of patient-centred research for increasing engagement, promoting treatment adherence, and optimising health outcomes. Qualitative evidence synthesis can be used to systematically identify and integrate the available evidence, identify research gaps, and provide essential insights for decision makers.

1. Qualitative evidence and the European Medicines Agency

The European Medicine Agency’s Strategy for 2025 emphasises how the patient’s experience, knowledge, and expertise should be integrated into evidence generation, stressing that ’understanding how to generate, analyse and use relevant patient data will be key for EMA’s regulatory science strategy’. The EMA recommends systematic integration of patient data into regulatory decision-making, including patient-reported, health-related quality of life as well as the assessment of benefits, harms, and uncertainties. This can be achieved by using patient-reported outcomes and disease-specific focus groups, and by engaging with patients and other stakeholders during the development of medicines targeting unmet needs.

2. Qualitative evidence and the National Institute for Health and Care Excellence

Since its inception, the National Institute for Health and Care Excellence (NICE) in the UK has involved patients in HTA. During each HTA, patients and other interested groups are invited to submit written and oral statements to the NICE assessment committee. NICE solicits such input at all HTA stages, from the initial scoping of topics to be assessed through to development of the final guidance. During evidence submission, patients and their caregivers can provide testimonials directly to the assessment committee.

Qualitative evidence synthesis and Symmetron

Qualitative evidence synthesis promotes the integration of patients’ voices throughout the technology development lifecycle, optimising the acceptability, feasibility, and relevance of an intervention (Figure 1.). At Symmetron, health outcomes researchers work closely with you to integrate qualitative evidence synthesis as deeply into the development lifecycle as possible. By synthesising the experiences and views of relevant stakeholders, including patients and healthcare providers, we can help you prospectively identify and understand obstacles that may hinder the implementation of your technology, permitting timely course corrections that ensure the most appropriate use of your valuable resources.

Figure 1. Qualitative evidence synthesis throughout the technology development lifecycle.