Health status, respiratory symptom and dyspnea trajectories in subjects with chronic obstructive pulmonary disease: a seven-year observation in clinical practice.

Abstract

Background: Chronic obstructive pulmonary disease (COPD) is characterized by progressive airflow limitation, often associated with declining health status. It is widely believed that the burden of the disease increases over time, leading to continuous suffering in the patient. Understanding the long-term course of patient-reported outcomes (PROs) and the variability in disease progression is crucial for effective management. The purpose of this research was to investigate the long-term trajectories of health status, respiratory symptoms, and dyspnea in COPD patients over a seven-year period and to identify factors associated with different progression patterns.

Methodology: This longitudinal study followed 70 COPD patients for seven years, with evaluations every six months. Participants underwent pulmonary function tests and completed four PRO measures: St. George's Respiratory Questionnaire (SGRQ), COPD Assessment Test (CAT), Evaluating Respiratory Symptoms in COPD (E-RS), and Dyspnoea-12 (D-12). Annual changes were estimated using linear mixed models and linear regression analysis. The patients were categorized into quartiles based on the rate of decline in forced expiratory volume in one second (FEV₁) and changes in PROs.

Results: The group showed a significant deterioration in the FEV₁ and PRO measures. FEV₁ declined by 25 milliliters annually, while SGRQ Total and CAT scores worsened by 1.4 and 0.6 units per year, respectively. However, substantial variability was observed between individuals. The SGRQ Total score worsened significantly after 1.0 year in the 4th quartile, while the 1st quartile showed improvements at 2.0, 2.5, 3.0, 4.0, 6.0 and 6.5 years. Similarly, while the CAT, E-RS Total and D-12 Total scores deteriorated in the fourth quartile, they remained stable or improved in the first quartile.

Conclusions: The progression of COPD varies widely among individuals. Although some patients experience significant declines, others remain stable or even improve for seven years. These findings challenge the belief that COPD inevitably leads to a constant increase in the burden of disease.