Diagnostic Instability and Reversals of Chronic Obstructive Pulmonary Disease Diagnosis in Individuals with Mild to Moderate Airflow Obstruction.
Pubmed ID: 28267373
Journal: American journal of respiratory and critical care medicine
Publication Date: 08/01/2017
Affiliation: 4 Desautels Faculty of Management, McGill University, Montreal, Quebec, Canada.
MeSH Terms: Humans, Male, Adult, Female, Cohort Studies, Middle Aged, Longitudinal Studies, Forced Expiratory Volume, Prospective Studies, Vital Capacity, Severity of Illness Index, Pulmonary Disease, Chronic Obstructive, Spirometry, Airway Obstruction
Authors: Sin DD, Aaron SD, Tan WC, Bourbeau J, Loves RH, MacNeil J, Whitmore GA
Cite As: Aaron SD, Tan WC, Bourbeau J, Sin DD, Loves RH, MacNeil J, Whitmore GA, Canadian Respiratory Research Network. Diagnostic Instability and Reversals of Chronic Obstructive Pulmonary Disease Diagnosis in Individuals with Mild to Moderate Airflow Obstruction. Am J Respir Crit Care Med 2017 Aug 1;196(3):306-314.
RATIONALE: Chronic obstructive pulmonary disease (COPD) is a chronic, progressive disease, and reversal of COPD diagnosis is thought to be uncommon. OBJECTIVES: To determine whether a spirometric diagnosis of mild or moderate COPD is subject to variability and potential error. METHODS: We examined two prospective cohort studies that enrolled subjects with mild to moderate post-bronchodilator airflow obstruction. The Lung Health Study (n = 5,861 subjects; study duration, 5 yr) and the Canadian Cohort of Obstructive Lung Disease (CanCOLD) study (n = 1,551 subjects; study duration, 4 yr) were examined to determine frequencies of (1) diagnostic instability, represented by how often patients initially met criteria for a spirometric diagnosis of COPD but then crossed the diagnostic threshold to normal and then crossed back to COPD over a series of annual visits, or vice versa; and (2) diagnostic reversals, defined as how often an individual's COPD diagnosis at the study outset reversed to normal by the end of the study. MEASUREMENTS AND MAIN RESULTS: Diagnostic instability was common and occurred in 19.5% of the Lung Health Study subjects and 6.4% of the CanCOLD subjects. Diagnostic reversals of COPD from the beginning to the end of the study period occurred in 12.6% and 27.2% of subjects in the Lung Health Study and CanCOLD study, respectively. The risk of diagnostic instability was greatest for subjects whose baseline FEV<sub>1</sub>/FVC value was closest to the diagnostic threshold, and the risk of diagnostic reversal was greatest for subjects who quit smoking during the study. CONCLUSIONS: A single post-bronchodilator spirometric assessment may not be reliable for diagnosing COPD in patients with mild to moderate airflow obstruction at baseline.