Reporting quantitative information in qualitative research: guidance for authors and reviewers

The absence of numbers is often seen as a defining feature of qualitative research 1. Despite this, qualitative researchers frequently use numbers or semi-quantification (e.g. terms such as ‘many’ or ‘most’) when writing up their data. We have found that different qualitative researchers can have strongly held, but opposing, views on whether and how quantitative information should be expressed in what are essentially qualitative studies (that is, studies reporting concepts, themes and ideas arising from interviews, group discussions or other linguistic material). This editorial note seeks to provide clarity for Addiction authors and reviewers on the Journal's current position and preferences. First, let us consider why researchers might want to convey quantitative or semi-quantitative information in reports from qualitative studies. The use of numbers to describe sample characteristics (e.g. number of participants and key demographics) is essential and uncontroversial. Beyond that, it has been argued that quantification or semi-quantification can improve the transparency of data analysis 2, give precision to statements 3, enable patterns in the data to emerge with greater clarity 4 and increase the meaning of key findings by providing focus 5. Quantification or semi-quantification can, however, be problematic. For example, if not everyone has been asked exactly the same questions in the same way, reporting or alluding to the frequency of a given response or emergent theme will probably misrepresent the data, even within the sample studied. In addition, the use of numbers tends to detract from the more valuable, detailed and nuanced data that are collected in qualitative work 6. A more conceptual concern, meanwhile, is that presenting numbers implies an ‘objective’ and measurable reality that is incompatible with the goals of qualitative research 3. Finally, presenting numbers can sometimes lead both the author and the reader to make inappropriate generalizations about the findings, albeit unconsciously 3, 6. Ritchie but it is not meant to convey generalizability beyond the study population 7. When submitting qualitative papers to Addiction, it might help to refer to this editorial note to assist reviewers who may otherwise provide inconsistent recommendations for revision. We will keep this guidance under review and welcome suggestions for improvement. Joanne Neale: None. Peter Miller has no affiliations which he believes constitute a conflict of interest. In the past 5 years he has been funded by charitable foundations, government departments and a pharmaceutical company via an intermediary charity. Travel expenses have been paid by charities, the Society for the Study of Addiction and university sources. He holds no stocks in any related companies. Robert West has received travel funds and hospitality from, and undertaken research and consultancy for, pharmaceutical companies that manufacture or research products aimed at helping smokers to stop. These products include nicotine replacement therapies and Zyban (bupropion). This has led to payments to him personally and to his institution. He undertakes lectures and training in smoking cessation methods which have led to payments to him personally and to his institution. He has received research grants from medical charities and government departments.