Published online: February 9, 2018
Asthma and chronic obstructive pulmonary disease (COPD) are the two most common obstructive airway diseases. Asthma−COPD overlap (ACO) is identified in clinical practice by features that it shares with asthma and COPD. Despite the large number of affected patients and greater risk of acute exacerbation, ACO continues to present a therapeutic dilemma. The appropriate treatment of ACO remains unclear, particularly as patients with asthma have been excluded from clinical trials examining COPD, and vice versa.
In a recently published article in The Journal of Allergy and Clinical Immunology: In Practice, Su and colleagues conducted a nationwide population-based study to investigate medication effects in patients with ACO. Using Taiwan’s National Health Insurance Research Database, patients diagnosed with both asthma and COPD between 1997 and 2012 were enrolled as the study cohort. The primary endpoint was acute exacerbation.
This study included 251,398 patients with both COPD and asthma with a mean follow-up period of 11.16 years. The validation study confirmed the accuracy of definitions of COPD (86.2% sensitivity) and asthma (92.0% sensitivity). After adjustment, hazard ratios for long-acting muscarinic antagonist (LAMA, 0.51, 95% CI 0.49–0.54) and inhaled corticosteroid/long-acting beta 2 agonist (ICS/LABA) combinations (0.61, 95% CI 0.60–0.62) were lower than were those for LABAs or ICSs in patients with COPD and asthma.
Based on current guidelines, more research is urgently needed to guide appropriate treatment for patients with ACO. In this study, LAMA or ICS/LABA combination use was associated with a lower risk of acute exacerbation in patients with ACO. LAMA or ICS/LABA combinations may be an appropriate starting therapy in patients with ACO.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.