OBJECTIVES: Chronic Obstructive Pulmonary Disease (COPD) is a chronic respiratory disease with a high burden of disease and a relevant Public Health problem. The active patient active involvement is crucial to yield the proper disease control. The aim of the study was to assess treatment adherence with the combination of inhaled corticosteroids (ICS) and long-acting beta-2 agonists (LABA), known as ICS/LABA, in the same fixed dose combination inhalers, depending on the inhaler device used: pressurized metered dose inhalers (pMDI) or dry powder inhalers (DPI), for the treatment of COPD in a real world backgroung. Additionally COPD exacerbations, resources consumption, and associated costs were recorded. METHODS: An observational, retrospective study was performed. Patients aged ≥ 40 years, diagnosed with COPD, and who initiated an ICS/LABA combination treatment during 2007-2011. Patients follow-up lasted for 3 years. Two treatment groups of patients were identified and assessed, depending on the inhaler device used: pMDI or DPI. The main measures were: adherence (posession drug ratio), persistence, asthma severity, ICS/LABA combinations used, exacerbations, resources use and their costs (direct and indirect costs). Multivariate methods were used for the variables correction, with a p significance degree ‹0.05. RESULTS: We included 1,418 COPD patients. Mean age 72.1 years, 82.7% male: 594 patients (41.9%) received an pMDI and 824 patients (58.1%) received an DPI. Patients who used and pMDI device showed a higher treatment adherence (RPM: 83.3% vs 79.9%, p<0.05), fewer number of exacerbations (40.1% vs 48.2%, p=0.002), and a lower health cost (€3,943 vs €4,621, p<0.001). CONCLUSIONS: Despite the limitations of the study, patients with COPD who started an ICS/LABA therapy who were treated with an pMDI device had higer adherence rates, better health outcomes and lower health costs for the Spanish National Health System.