PurposeTriple therapy versus dual therapy for chronic pulmonary obstructive disease (COPD) can reduce symptoms, limit the risk of acute exacerbations (AEs) as well as improve lung function. Currently, studies that feature clinically important deterioration (CID) as a composite endpoint to assess the need for treatment intensification for patients maintained on dual therapy remained to be scarce.Patients and MethodsThis study is a retrospective analysis (January 2014 to January 2018) of COPD patients that presented with moderate to severe AEs during the previous year with blood eosinophil counts ≥ 100 cells/μL. The first line of therapy included a combination of inhaled corticosteroid (ICS) and a long-acting β2 agonist (LABA). Composite CID was used in assessing the response to treatment after 24 weeks of therapy.ResultsThis study included 110 patients, of which 49 patients reportedly experienced CID. The most common events of CID include a decline in forced expiratory volume in 1 second (FEV1) ≥ 100 mL from baseline (25/49, 51%) and an increase in COPD Assessment Test (CAT) scores ≥ 2 (13/49, 26.5%); many of these patients respond to the addition of a long-acting muscarinic antagonist (LAMA). Seven patients (7/110, 6.3%) experienced moderate to severe exacerbations while undergoing treatment with ICS/LABA. Univariate and multivariate analyses have identified low baseline FEV1 (OR = 0.81, p = 0.004), high CAT score (OR = 1.89, p = 0.004), and the frequency of AE (OR = 19.86, p = 0.021) as independent predictors of CID. A baseline FEV1 of ≤42%, an initial CAT score ≥ 18, and AE ≥ 2 last year were considered the optimal cut-off values, which were identified via receiver operating characteristics (ROC) curve analysis.ConclusionTriple therapy (ICS/LABAs/LAMAs) may be considered as first-line treatment in patients experiencing more than 2 times moderate to severe AEs of COPD in the previous year and who have blood eosinophil counts ≥100 cells/μL, reduced lung function (FEV1 ≤ 42%), and more symptoms (CAT score ≥ 18).