Findings on Thoracic Computed Tomography Scans and Respiratory Outcomes in Persons with and without Chronic Obstructive Pulmonary Disease: A Population-Based Cohort Study

• Published in: PloS one Vol. 11; no. 11; p. e0166745
• Main Authors: Tan, Wan C., Hague, Cameron J., Leipsic, Jonathon, Bourbeau, Jean, Zheng, Liyun, Li, Pei Z., Sin, Don D., Coxson, Harvey O., Kirby, Miranda, Hogg, James C., Raju, Rekha, Road, Jeremy, O’Donnell, Denis E., Maltais, Francois, Hernandez, Paul, Cowie, Robert, Chapman, Kenneth R., Marciniuk, Darcy D., FitzGerald, J. Mark, Aaron, Shawn D.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 18.11.2016; Public Library of Science (PLoS)
• Subjects: Abnormalities; Adult; Aged; Aged, 80 and over; Airway management; Asthma; Biology and Life Sciences; Bronchiectasis; Bronchopneumonia; Canada - epidemiology; CAT scans; Chronic obstructive lung disease; Chronic obstructive pulmonary disease; Cohort analysis; Cohort Studies; Collaboration; Computation; Computed tomography; Cough; Critical care; Dyspnea; Emphysema; Epidemiology; Female; Health sciences; Heart; Hospitals; Humans; Lung diseases; Male; Medical imaging; Medical research; Medicine and Health Sciences; Middle Aged; Obstructive lung disease; Odds Ratio; Outcome Assessment, Health Care; Physiology; Population; Population studies; Population Surveillance; Population-based studies; Prevalence; Pulmonary Disease, Chronic Obstructive - diagnostic imaging; Pulmonary Disease, Chronic Obstructive - epidemiology; Pulmonary Disease, Chronic Obstructive - physiopathology; Quality of life; Radiology; Regression analysis; Regression models; Research and Analysis Methods; Respiration; Respiratory function; Respiratory Function Tests; Respiratory tract; Self Report; Severity of Illness Index; Smokers; Smoking; Thickening; Thorax; Tomography, X-Ray Computed; Yang, Cindy; Canada; Montreal Quebec Canada; Quebec Canada
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0166745

Thoracic computed tomography (CT) scans are widely performed in clinical practice, often leading to detection of airway or parenchymal abnormalities in asymptomatic or minimally symptomatic individuals. However, clinical relevance of CT abnormalities is uncertain in the general population. We evaluated data from 1361 participants aged ≥40 years from a Canadian prospective cohort comprising 408 healthy never-smokers, 502 healthy ever-smokers, and 451 individuals with spirometric evidence of chronic obstructive pulmonary disease (COPD) who had thoracic CT scans. CT images of subjects were visually scored for respiratory bronchiolitis(RB), emphysema(E), bronchial-wall thickening(BWT), expiratory air-trapping(AT), and bronchiectasis(B). Multivariable logistic regression models were used to assess associations of CT features with respiratory symptoms, dyspnea, health status as determined by COPD assessment test, and risk of clinically significant exacerbations during 12 months follow-up. About 11% of life-time never-smokers demonstrated emphysema on CT scans. Prevalence increased to 30% among smokers with normal lung function and 36%, 50%, and 57% among individuals with mild, moderate or severe/very severe COPD, respectively. Presence of emphysema on CT was associated with chronic cough (OR,2.11; 95%CI,1.4-3.18); chronic phlegm production (OR,1.87; 95% CI,1.27-2.76); wheeze (OR,1.61; 95% CI,1.05-2.48); dyspnoea (OR,2.90; 95% CI,1.41-5.98); CAT score≥10(OR,2.17; 95%CI,1.42-3.30) and risk of ≥2 exacerbations over 12 months (OR,2.17; 95% CI, 1.42-3.0). Burden of thoracic CT abnormalities is high among Canadians ≥40 years of age, including never-smokers and smokers with normal lung function. Detection of emphysema on CT scans is associated with pulmonary symptoms and increased risk of exacerbations, independent of smoking or lung function.