Health-related quality of life in a nationwide cohort of patients with COPD related to other characteristics

BACKGROUND In chronic obstructive pulmonary disease (COPD), various factors, such as dyspnoea, obstruction, exacerbations, smoking, exercise capacity, and body mass index, have been found to influence mortality and health-related quality of life (HRQOL). In order to identify subgroups of patients needing special attention, the aim of the present study was to explore the relationships between disease progression factors and HRQOL across COPD stages. METHODS Baseline registrations from the Swedish COPD register of demographic, clinical, and patient-reported variables of 7,810 patients are presented. Dyspnoea was measured by the modified Medical Research Council (mMRC) dyspnoea scale and HRQOL by the Clinical COPD Questionnaire (CCQ). RESULTS This study shows as expected that patients with spirometrically more severe COPD had a significantly higher number of exacerbations and hospitalisations, significantly increasing dyspnoea, significantly decreasing body mass index and exercise capacity, and significantly worsening HRQOL. When adjusting for spirometric stage of COPD, deteriorated HRQOL was predicted by increasing dyspnoea, depression/anxiety, increasing number of exacerbations, and decreased exercise capacity. Further, these data show that an mMRC value of 2 corresponds to a CCQ value of 1.9. CONCLUSION The COPD patients suffered from a significant symptom burden, influencing HRQOL. A surprisingly great proportion of patients in spirometric stages II-IV showed marked changes of CCQ, indicating a need for an improved collaboration between clinical pulmonary medicine and palliative care.