A conceptual model of the experience of dyspnea and functional limitations in chronic obstructive pulmonary disease

Objectives: Identify important patient-reported concepts of dyspnea and associated activities to develop a dyspnea-specific conceptual model for chronic obstructive pulmonary disease (COPD). Methods: Using grounded theory methodologies, we identified key concepts through interviews with 25 COPD patients, review of scientific literature, and input from 22 experts. Results: Constant comparative thematic analysis of data suggested five primary components of the dyspnea experience: breathlessness, fatigue, activity modification, activity limitation, and emotional response. Two major influences on dyspnea were described as individual exertion and exposure to environmental factors. Patients described a sense of dyspnea-related fear, and reported distress over the impact of dyspnea on health and activity limitation. They emphasized coping via behavioral strategies and medication, and reported that dyspnea caused the stopping or scaling back of activities, taking more time to do things and using adaptive measures or equipment. No existing model of dyspnea in COPD incorporated all of these concepts. We, therefore, developed a dyspnea-specific conceptual model in which the most proximal of concepts (dyspnea symptoms) can impair function and are mediated by personal and environmental factors. Conclusion: Patient and expert input guided the development of a comprehensive dyspnea-specific conceptual model for COPD which will inform the design of future patient-reported outcome measurement tools used to assess dyspnea and related functional limitations.