Abstract
INTRODUCTION: The Quality of Life-Bronchiectasis (QOL-B) questionnaire and Patient Reported Outcome Measurement Information System Short Form v1.0-Fatigue 7a (PROMIS-F SF-7a) have the potential to measure respiratory and fatigue symptoms, respectively, in patients with Mycobacterium avium complex (MAC) lung disease but have not yet been evaluated for content validity in this population. METHODS: Semi-structured qualitative interviews were conducted in United States patients with a current MAC lung disease diagnosis. Concept elicitation (CE) interviews were conducted (n = 25 participants) to identify key respiratory and fatigue symptoms expressed as important and relevant to patients with MAC lung disease and to evaluate the appropriateness of the QOL-B and PROMIS-F SF-7a to measure these symptoms. Cognitive interviews (CIs) were subsequently conducted (n = 20 participants) to evaluate the relevance, comprehensibility, and appropriateness of the QOL-B respiratory domain (QOL-B-RD) and PROMIS-F SF-7a. All interviews were recorded, transcribed, and coded for qualitative content analysis. RESULTS: The most important or relevant respiratory symptom concepts to CE interview participants were "cough," "shortness of breath during activity," and "mucus/phlegm." The most important or relevant fatigue symptom concepts were "tiredness," "lack of energy," and "tire easily/low stamina." These symptoms are covered by existing items in the QOL-B-RD and PROMIS-F SF-7a. Cognitive interview participants' feedback confirmed the item content, response options, concept attributes, and recall period for each instrument were effective, relevant, and meaningful to most patients with MAC lung disease. Based on Wave 1 findings, the QOL-B instructions were revised for the Wave 2 interviews, where the text referencing "bronchiectasis" was replaced with "your lung condition." Participant feedback in Wave 2 confirmed the revised instruction wording was easily understood and appropriate. CONCLUSIONS: The study results support the content validity of the QOL-B-RD and PROMIS-F SF-7a, which were shown to be relevant and appropriate to evaluate respiratory and fatigue symptoms, respectively, in patients with MAC lung disease.