Quality of life in coeliac disease: qualitative interviews to develop candidate items for the Coeliac Disease Assessment Questionnaire

Abstract

Background Coeliac-specific measures have been criticized for not complying with current guidance on the development of patient-reported outcome measures (PROMs). The aim of this study was to develop a measure to assess health-related quality of life in adults with coeliac disease (CD), in accordance with current guidance for PROM development. Methods In-depth qualitative interviews were conducted with adults with CD. A thematic analysis was undertaken to develop a coding framework. All interviews were analyzed according to this framework. Interviewing continued until data saturation was achieved. Candidate items were developed on the basis of the interview findings. Results The analysis revealed 6 themes: 1) symptoms, 2) gluten-free diet, 3) emotional health, 4) impact on activities, 5) relationships, and 6) financial issues. Data saturation was reached after 8 interviews, but a total of 23 interviews were conducted to include a wide enough range of diverse participants. From the themes, 64 candidate items (9 for symptoms, 15 for emotional health, 16 for gluten-free diet, 7 for relationships, 12 for impact on activities, and 5 for financial issues) were developed to form the first draft of the Coeliac Disease Assessment Questionnaire (CDAQ). Conclusion The 64 items reflect all the issues of importance to people with CD. Next, these items will be pretested and refined to lead to a shorter draft version of the CDAQ before it is administered in a survey to produce a final version with subscales.