Dyspnea as clinical indicator in patients with chronic obstructive pulmonary disease

The aim of this study was to evaluate the relationship between dyspnea and functional, psychosocial and quality of life parameters among persons with chronic obstructive pulmonary disease (COPD). We conducted a cross-sectional study of 90 stable COPD patients recruited from a specialized respiratory clinic. Dyspnea was measured using the ATS-DLD-78 questionnaire modified dyspnea scale (1-5 scale). Physical and functional evaluation included spirometry and six minute walking tests. Subjects then completed five psychological questionnaires: the Coping Inventory for Stressful Situations, the State/Trait Anxiety Inventory, the Beck Depression Index, the NEO-Five Factor Personality Inventory, and the Interpersonal Relationships Inventory. Patients also completed two disease-specific health-related quality of life (HRQL) questionnaires: St. George's Respiratory Questionnaire (SGRQ) and Chronic Respiratory Questionnaire (CRQ). Subjects were predominantly male (n = 65) with a mean age of 68 years (±standard deviation 7.6). Over half (54%) the patients reported severe dyspnea (grade 5), and a quarter (24%) reported moderate dyspnea (grade 3-4). Mean FEV₁ was 37.8 ± 14.8% predicted. The mean total SGRQ score was 49 ± 16 and the CRQ total score was 4.2 ± 0.9. Dyspnea severity was associated with poorer HRQL scores and decreased physical performance. Based on linear regression, dyspnea scores - but not spirometric values - also correlated with indices of anxiety, depression, and neuroticism. Dyspnea correlated more strongly with HRQL and with indices of anxiety and depression than spirometric values. Although spirometry is often used to evaluate disease severity, dyspnea which is a patient centered outcome better reflect overall disease impact among COPD patients.