The variability of respiratory symptoms and associated factors in COPD

- 48% of patients reported night-time symptoms and 71% reported morning symptoms.
- There is a high variability in number and intensity of symptoms over a week.
- Dyspnea, exacerbations and asthma-COPD are associated with variability of symptoms.

Few studies have investigated the variability of COPD-related symptoms or factors related to symptom variability.This observational, prospective, multicentre study was conducted to describe the number and intensity of morning and night-time respiratory symptoms and their variability over one week using the Night-time and Early Morning Symptoms of COPD Instruments (NiSCI and EMSCI) to evaluate stable COPD patients. Logistic regression analyses were performed to investigate factors associated with symptom variability.A total of 2669 patients were evaluated (mean age, 67.7 years; 80.9% men; mean FEV1 50.6%). Of these, 48% reported night-time symptoms and 71% reported morning symptoms. Of the 2293 patients who completed the NiSCI and EMSCI, 90% showed variability in either symptom number (89.6%) or symptom intensity (15.8%). More severe dyspnoea, more exacerbations during the previous year and the exacerbator or mixed COPD-asthma phenotypes were associated with variability in symptom number or intensity. Anxiety was significantly associated with variability in symptom number and intensity.Most COPD patients showed symptom variability over a weeklong period, especially in terms of symptom number. Several COPD-related factors, mainly factors related to more severe disease and more frequent exacerbations, were associated with increased symptom variability.