Understanding asthma-chronic obstructive pulmonary disease overlap syndrome

• Published in: Respiratory medicine Vol. 110; pp. 1 - 11
• Main Authors: Wurst, Keele E, Kelly-Reif, Kaitlin, Bushnell, Greta A, Pascoe, Steven, Barnes, Neil
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.2016; Elsevier Limited
• Subjects: Adolescent; Adult; Age; Aged; Aged, 80 and over; Airway management; Asthma; Asthma - classification; Asthma - complications; Asthma - diagnosis; Asthma - epidemiology; Asthma-chronic obstructive pulmonary disease overlap syndrome; Chronic obstructive pulmonary disease; Clinical trials; Codes; Genotype & phenotype; Humans; Inflammation; Lung diseases; Medicaid; Meetings; Middle Aged; Mortality; Older people; Patients; Pulmonary Disease, Chronic Obstructive - classification; Pulmonary Disease, Chronic Obstructive - complications; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - epidemiology; Pulmonary/Respiratory; Respiratory diseases; Studies; Young Adult; GOLD; Global Initiative for Chronic Obstructive Lung Disease; forced vital capacity; IHCIS; Latin American Project for the Investigation of Lung Disease; International Classification of Disease; lower limit of normal; Saint George's Respiratory Questionnaire; SPIROMICS; COPDGene; Gene–Environment Interactions in Respiratory Disease; LLN; Integrated Healthcare Information Services; Genetic Epidemiology of COPD; peak expiratory flow; GEIRD; ACOS; Unbiased BIOmarkers in PREDiction of respiratory outcomes; Chronic obstructive pulmonary disease; BOLD; North Carolina Behavioral Risk Factor Surveillance System; National Health and Nutritional Examination Survey; PLATINO; Burden of Obstructive Lung Disease; Subpopulations and intermediate outcome measures in COPD study; U-BIOPRED; ICD; NC BRFSS; Asthma; forced expiratory volume in one second; PEF; FVC; FEV 1; GINA; Global Initiative for Asthma; SGRQ; Asthma-chronic obstructive pulmonary disease overlap syndrome; NHANES; COPD; FEV1
• ISSN: 0954-6111; 1532-3064
• DOI: 10.1016/j.rmed.2015.10.004

Abstract Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is a loosely-defined clinical entity referring to patients who exhibit characteristics of both asthma and chronic obstructive pulmonary disease (COPD). Clinical definitions and classifications for ACOS vary widely, which impacts our understanding of prevalence, diagnosis and treatment of the condition. This literature review was therefore conducted to characterize the prevalence of ACOS and the effect of different disease definitions on these estimates, as this has not previously been explored. From an analysis of English language literature published from 2000 to 2014, the estimated prevalence of ACOS ranges from 12.1% to 55.2% among patients with COPD and 13.3%–61.0% among patients with asthma alone. This variability is linked to differences in COPD and asthma diagnostic criteria, disease ascertainment methods (spirometry-based versus clinical or symptom-based diagnoses and claims data), and population characteristics including age, gender and smoking. Understanding the reasons for differences in prevalence estimates of ACOS across the literature may help guide decision making on the most appropriate criteria for defining ACOS and aid investigators in designing future ACOS clinical studies aimed at effective treatment.