Asthma, COPD, and overlap in a national cohort: ACO on a gradient

• Published in: Journal of allergy and clinical immunology 2018-04, Vol.141 (4), p.1516-1518
• Main Authors: Bourdin, Arnaud, Suehs, Carey M., Marin, Gregory, Vachier, Isabelle, Matzner-Lober, Eric, Chanez, Pascal, Molinari, Nicolas
• Format: Article
• Language: English
• Subjects: Adrenal Cortex Hormones - therapeutic use; Adult; Allergology; Asthma; Asthma - diagnosis; Asthma - drug therapy; Chronic obstructive pulmonary disease; Corticosteroids; Hospitalization; Humans; Immunology; Intensive care; Life Sciences; Lung diseases; Patients; Pulmonary Disease, Chronic Obstructive - diagnosis; Pulmonary Disease, Chronic Obstructive - drug therapy; Santé publique et épidémiologie; Values; Variables
• ISSN: 0091-6749; 1097-6825
• DOI: 10.1016/j.jaci.2017.11.049

In older patients (typically older than 40 years), distinguishing between them becomes difficult because patients can increasingly share characteristics of either disease, resulting in “asthma-COPD overlap” (ACO).1 Diagnosing ACO has been justified by reports of poorer outcomes for “intermediate” patients when compared with those who have clear diagnoses of asthma or COPD alone.1,2 Treatment options and responses may also differ, notably by the fact that patients with ACO have been found to better respond to inhaled corticosteroids as compared with patients with COPD.3,4 However, certain authors have expressed concern when blurring the lines between asthma and COPD, citing the potential for overmedication as a concern,5-7 as well as the lack of studies supporting specific treatments for intermediate groups.5,8 Nevertheless, the ability to easily identify an expected “poor-outcome” group via overlapping asthma and COPD clinical characteristics would be of great utility for clinicians.8 In addition, an important part of nosology is identifying diseases with similar outcomes: testing whether or not the requalification of patients with asthma and COPD into an ACO group more accurately identifies subgroups in terms of prognosis may represent one argument justifying this refined classification. [...]clustering patients according to the simultaneous presence of clinical signs for both asthma and COPD resulted in an “overlap” group whose outcomes and disease severity were generally intermediate on an asthma-to-COPD gradient, with poorer lung function and outcomes on the COPD side of the gradient. Variable AsthmaK (n = 519) ACOK (N = 386) COPDK (n = 200) P value ACO-asthma (n = 338) ACO-COPD (n = 48) AsthmaK vs COPDK ACOK vs asthmaK ACOK vs COPDK ACO-asthma vs asthmaK ACO-COPD vs COPDK FEV1 pre-β2 (L) 2.40 (1.63 to 3.06) 2.02 (1.54 to 2.59) 1.48 (0.95 to 2.09)