Qualitative research as evidence: expanding the paradigm for evidence-based healthcare

Correspondence to Dr Veronika Williams, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford OX2 6GG, UK; [email protected]

Writing in the BMJ, David Sackett and John Wennberg pointed out over 20 years ago we need to stop ‘squabbling over the best methods’ and focus on the research question, since it is the nature of the question that determines the best research design to answer it.¹ Yet, the majority of evidence hierarchies and ‘levels’² still do not include qualitative methodologies, and Evidence-based Health Care  (EBHC) still largely focuses on the positivist perspective of generating and applying knowledge in healthcare practice.³ Despite its lack of prominence in EBHC, qualitative research in healthcare has increasingly been conducted and published since Sackett and Wennberg’s editorial, and the publication of qualitative evidence syntheses have doubled in the past decade.⁴

The argument for qualitative research within EBHC has been made for over 20 years,⁵ including a series of educational articles in the BMJ ^6–9 and all of which have citations in the 1000s. NB: the journal has since reversed their position on qualitative research to one where qualitative research seems no longer a priority for the journal to the dismay of prominent proponents.¹⁰

To understand why qualitative research has yet to achieve the same status as other forms of evidence within the evidence-based healthcare movement, we need to consider wider contextual factors surrounding research and the underlying epistemological differences between the quantitative and qualitative paradigms.

Qualitative research can be of exploratory and/or explanatory nature. It seeks to answer ‘how’ and ‘why’ questions rather than trying to establish causation or correlation using statistical methods and aims to explore different perspectives and experiences of phenomena.¹¹ It falls within an interpretivist/constructivist paradigm (interpretivism assumes that the world does not exist independently of our knowledge of it. Knowledge and meaningful reality are constructed in and out of interaction between humans and their world and are developed and transmitted in a social context), which cannot and indeed does not aim to make definitive statements about its research findings.¹¹ The underlying premise of methodologies that use qualitative methods does not assume one truth that can be verified and replicated but rather several truths that are...