Qualitative Interviews to Support Development and Cognitive Debriefing of the Adelphi Adherence Questionnaire (ADAQ©): A Patient-Reported Measure of Medication Adherence Developed for Use in a Range of Diseases, Treatment Modalities, and Countries

Sarah Bentley,1 Lucy Morgan,1 Elizabeth Exall,1 Rob Arbuckle,1 Rebecca C Rossom,2 Nicholas Roche,3 Kamlesh Khunti,4 Victoria Higgins,5 James Piercy5 1Patient-Centered Outcomes, Adelphi Values, Bollington, Cheshire, UK; 2HealthPartners Institute, University of Minnesota Medical School, Minneapolis, MN, USA; 3Respiratory Medicine, Cochin Hospital, APHP Centre University Paris Cité, Institut Cochin (UMR1016), Paris, France; 4Diabetes Research Centre, Leicester University, Leicester, UK; 5Adelphi Real World, Bollington, Cheshire, UKCorrespondence: Rob Arbuckle, Patient-Centered Outcomes, Adelphi Values, Bollington, Cheshire, UK, Tel +44 7720 880884, Email rob.arbuckle@Adelphivalues.comPurpose: The Adelphi Adherence Questionnaire (ADAQ©) is a newly developed generic patient-reported outcome (PRO) assessment of medication adherence. The aim was to assess its content validity by conducting cognitive debriefing (CD) interviews with patients prescribed medication(s) of various treatment modalities in a range of therapy areas.Materials and Methods: Targeted literature/instrument review and concept elicitation interviews informed development of the ADAQ©. CD interviews were conducted with 57 adults from the United States of America (USA; n = 21), Spain (n = 18), and Germany (n = 18) who prescribed medication for hypertension, diabetes, depression, schizophrenia, asthma, multiple myeloma, psoriasis, and/or multiple sclerosis. Interviews were conducted in two rounds to explore the relevance and understanding of the item wording, instructions, recall period and response options. Verbatim transcripts were analysed in ATLAS.Ti using thematic analysis. Three expert clinicians provided guidance throughout the study.Results: ADAQ© items/instructions were well understood and relevant to participants. Key modifications following round 1 included revising instructions to refer to current medication(s) for one condition to reduce cognitive burden, removing two items with lower relevan