Exacerbation-like respiratory symptoms in individuals without chronic obstructive pulmonary disease: results from a population-based study.
BACKGROUND
Exacerbations of COPD are defined clinically by worsening of chronic respiratory symptoms. Chronic respiratory symptoms are common in the general population. There are no data on the frequency of exacerbation-like events in individuals without spirometric evidence of COPD.


OBJECTIVE
To determine the occurrence of 'exacerbation-like' events in individuals without airflow limitation, their associated risk factors, healthcare utilisation and social impacts.


METHODS
We analysed the cross-sectional data from 5176 people aged 40 years and older who participated in a multisite, population-based study on lung health. The study cohort was stratified into spirometrically defined COPD (post-bronchodilator FEV1/FVC < 0.7) and non-COPD (post bronchodilator FEV1/FVC ≥ 0.7 and without self-reported doctor diagnosis of airway diseases) subgroups and then into those with and without respiratory 'exacerbation-like' events in the past year.


RESULTS
Individuals without COPD had half the frequency of 'exacerbation-like' events compared with those with COPD. In the non-COPD group, the independent associations with 'exacerbations' included female gender, presence of wheezing, the use of respiratory medications and self-perceived poor health. In the non-COPD group, those with exacerbations were more likely than those without exacerbations to have poorer health-related quality of life (12-item Short-Form Health Survey), miss social activities (58.5% vs 18.8%), miss work for income (41.5% vs 17.3%) and miss housework (55.6% vs 16.5%), p<0.01 to <0.0001.


CONCLUSIONS
Events similar to exacerbations of COPD can occur in individuals without COPD or asthma and are associated with significant health and socioeconomic outcomes. They increase the respiratory burden in the community and may contribute to the false-positive diagnosis of asthma or COPD.
UBC James Hogg Research Center, Providence Heart + Lung Institute, St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
W C
WC
Tan
Respiratory Epidemiology and Clinical Research Unit, Montreal Chest Institute, McGill University, Montréal, Quebec, Canada.
J
J
Bourbeau
Respirology Division, Department of Medicine, QEII Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada.
P
P
Hernandez
Asthma & Airway Centre, University Health Network and University of Toronto, Toronto, Ontario, Canada.
K R
KR
Chapman
Departments of Medicine and Community Health Sciences, University of Calgary, Calgary, Alberta, Canada.
R
R
Cowie
University of British Columbia, Institute for Heart and Lung Health, Vancouver, British Columbia, Canada.
J M
JM
FitzGerald
Division of Respirology, Critical Care and Sleep Medicine, and Airway research Group, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.
D D
DD
Marciniuk
Centre de Pneumologie, Institute Universitaire de Cardiologie et de Pneumologie de Québec, Quebec, Canada.
F
F
Maltais
Oregon Health and Science University, Portland, Oregon, USA.
A S
AS
Buist
Division of Respiratory & Critical Care Medicine, Queen's University, Kingston, Ontario, Canada.
D E
DE
O'Donnell
UBC James Hogg Research Center, Providence Heart + Lung Institute, St Paul's Hospital, University of British Columbia, Vancouver, British Columbia, Canada.
D D
DD
Sin
Ottawa Hospital Research Institute, University of Ottawa, Ottawa, Ontario, Canada.
S D
SD
Aaron
D000203:Activities of Daily Living; D000208:Acute Disease; D000328:Adult; D000368:Aged; D000402:Airway Obstruction / Q000503:physiopathology*; D001249:Asthma / Q000503:physiopathology*; D001991:Bronchitis / Q000503:physiopathology*; D002170:Canada / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D011788:Quality of Life; D012129:Respiratory Function Tests; D012307:Risk Factors; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires; D014505:Urban Population
Asthma Epidemiology; COPD Exacerbations; Clinical Epidemiology