Article Text

Download PDFPDF
Critical appraisal of qualitative research: necessity, partialities and the issue of bias
  1. Veronika Williams,
  2. Anne-Marie Boylan,
  3. David Nunan
  1. Nuffield Department of Primary Care Health Sciences, University of Oxford, Radcliffe Observatory Quarter, Oxford, UK
  1. Correspondence to Dr Veronika Williams, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford OX2 6GG, UK; veronika.williams{at}

Statistics from


Qualitative evidence allows researchers to analyse human experience and provides useful exploratory insights into experiential matters and meaning, often explaining the ‘how’ and ‘why’. As we have argued previously1, qualitative research has an important place within evidence-based healthcare, contributing to among other things policy on patient safety,2 prescribing,3 4 and understanding chronic illness.5 Equally, it offers additional insight into quantitative studies, explaining contextual factors surrounding a successful intervention or why an intervention might have ‘failed’ or ‘succeeded’ where effect sizes cannot. It is for these reasons that the MRC strongly recommends including qualitative evaluations when developing and evaluating complex interventions.6

‘Qualitative research’ is an umbrella term that refers to various research methodologies including ethnography, phenomenology, action research, discourse analysis and grounded theory that use textual and/or visual rather than numerical data to explore meaning and perspectives of phenomena. However, it is often considered one unified approach and this lack of methodological distinction is problematic, particularly when thinking about how best to assess rigour in studies using qualitative methods.7–9

Critical appraisal of qualitative research

Is it necessary?

Although the importance of qualitative research to improve health services and care is now increasingly widely supported (discussed in paper 1), the role of appraising the quality of qualitative health research is still debated.8 10 Despite a large body of literature focusing on appraisal and rigour,9 11–15 often referred to as ‘trustworthiness’16 in qualitative research, there remains debate about how to —and even whether to—critically appraise qualitative research.8–10 17–19 However, if we are to make a case for qualitative research as integral to evidence-based healthcare, then any argument to omit a crucial element of evidence-based practice is difficult to justify. That being said, simply applying the standards of rigour used to appraise studies based on the positivist paradigm (Positivism depends on quantifiable observations …

View Full Text


  • Contributors VW and DN: conceived the idea for this article. VW: wrote the first draft. AMB and DN: contributed to the final draft. All authors approve the submitted article.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Correction notice This article has been updated since its original publication to include a new reference (reference 1.)

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.