OBJECTIVES: To develop and subsequently evaluate content validity of questions assessing patient preference between two dry powder inhaler (DPI) devices (the Handihaler and the Novel DPI) for the treatment of chronic obstructive pulmonary disease (COPD), based on ease of use.
METHODS: Initial COPD Device Preference Questionnaire (CDPQ) items were designed to assess inhaler device preference based on aspects of ease of use identified as important by COPD patients and physicians during previous research. Two iterative rounds of semistructured, indepth interviews were conducted in adult patients currently receiving COPD medication via the Handihaler. Initially, patients were asked to describe the actuation of the Handihaler. Next, the features and steps required to operate the Novel DPI were described, and participants were asked to demonstrate using an empty device. Cognitive debriefing of the CDPQ was then conducted. Patients completed and evaluated five items, each phrased two different ways (beginning with “which. . .” or “thinking. . .”). Round 1 interviews (n 8) gathered feedback on preferred phrasing and modifications required to improve the CDPQ. Round 2 interviews (n 8) assessed modifications and gathered additional input to confirm content validity. All interviews were recorded and transcribed for analysis.
RESULTS: Round 1 interviews resulted in addition of instruction detail, modification of questions based on a clear preference for the “which” phrasing, and removal of two items (i.e., understanding how to use the device and number of steps involved in preparing the device) deemed duplicative. Round 2 interviews did not result in additional changes. Participants found instructions, items, and response wording easy to understand and complete. An item-tracking grid was constructed to summarize item changes and their rationales.
CONCLUSIONS: Participant feedback indicates that the concepts of greatest importance in determining COPD inhaler device preference related to ease of use were reflected in the final CDPQ items.
