The Challenge
Researchers use both quantitative and qualitative methods to help them explore and address key research questions. Quantitative methods measure, analyse and produce numerical results, whilst qualitative methods explore people’s needs, behaviours, views and experiences using methods such as interviews and focus groups to produce narratives for analysis. Qualitative methods can also explore how well interventions are implemented and whether they work as intended.
Qualitative evidence syntheses combine and analyse, and sometimes transform evidence from qualitative studies to produce synthesised findings. It is less common for qualitative evidence syntheses to inform guideline development. Guideline developers do not know how much confidence they should place in each synthesised qualitative finding.

The Solution: A Step by Step Approach for Researchers and Guideline Developers
The GRADE-CERQual (‘Confidence in the Evidence from Reviews of Qualitative research’) approach helps decision makers use these syntheses by indicating how much confidence they should place in each finding.
The GRADE-CERQual Project Group has been set up to support the development of the CERQual approach (https://www.cerqual.org/). The group has produced a series of seven papers published in Implementation Science that take the reader through the GRADE-CERQual approach step-by-step.
In addition to explaining how the approach was created and developed, the papers aim to provide guidance on how to apply the approach, how to arrive at an overall assessment of confidence, and how to present key findings and confidence assessments
The series is intended primarily for those undertaking qualitative evidence syntheses or using their findings in decision-making processes but is also relevant to guideline development agencies, primary qualitative researchers and implementation scientists and practitioners.


The Impact
The GRADE-CERQual approach is already being used in guidelines produced by organisations such as the World Health Organization, the National Institute for Health and Care Excellence in the UK, the Swedish Council on Health Technology Assessment and the European Commission Initiative on Breast Cancer.
Guideline developers have endorsed the approach and incorporated CERQual into their processes. Decision-making is now undertaken differently with the inclusion of qualitative evidence to address specific questions that cannot be addressed by quantitative evidence alone.
Importantly, this series of papers support and provide CERQual users, worldwide, with step by step information on how to apply the approach. This support, in turn, will help review producers and guideline developers use qualitative evidence more widely and appropriately.