The variability of respiratory symptoms and associated factors in COPD

Respir Med. 2017 Aug;129:165-172. doi: 10.1016/j.rmed.2017.06.017. Epub 2017 Jun 26.


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.

Keywords: COPD; Quality of life; Sleep; Symptoms; Variability.

Publication types

  • Multicenter Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living / psychology
  • Aged
  • Anxiety / complications
  • Circadian Rhythm / physiology*
  • Comorbidity
  • Disease Progression
  • Dyspnea / diagnosis*
  • Dyspnea / drug therapy
  • Dyspnea / psychology
  • Female
  • Forced Expiratory Volume
  • Humans
  • Male
  • Middle Aged
  • Prospective Studies
  • Pulmonary Disease, Chronic Obstructive / diagnosis*
  • Pulmonary Disease, Chronic Obstructive / epidemiology
  • Pulmonary Disease, Chronic Obstructive / physiopathology*
  • Quality of Life
  • Severity of Illness Index
  • Sleep Wake Disorders / complications
  • Spirometry / methods
  • Vital Capacity