The importance of inhaler devices: the choice of inhaler device may lead to suboptimal adherence in COPD patients

Josep Darbà,1 Gabriela Ramírez,2 Antoni Sicras,3 Pablo Francoli,4 Saku Torvinen,5 Rainel Sánchez-de la Rosa4 1Department of Economics, Universitat de Barcelona, 2BCN Health Economics and Outcomes Research SL, 3Dirección de Planificación, Badalona Serveis Assistencials, SA, Barcelona, 4Medical Department, TEVA Pharmaceutical, Madrid, Spain; 5Market Access Department, TEVA Pharmaceutical Europe BV, Amsterdam, the Netherlands Objective: This study aims to identify factors associated with poor adherence to COPD treatment in patients receiving a fixed-dose combination (FDC) of inhaled corticosteroids and long-acting β2-agonist (ICS/LABA), focusing on the importance of inhaler devices.Methods: We conducted a retrospective and multicenter study based on a review of medical registries between 2007 and 2012 of COPD patients (n=1,263) treated with ICS/LABA FDC, whose medical devices were either dry powder inhalers (DPIs) or pressurized metered-dose inhalers (pMDI). Medication adherence included persistence outcomes through 18 months and medication possession ratios. Data on exacerbations, comorbidities, demographic characteristics, and health care resource utilization were also included as confounders of adherence.Results: The analyses revealed that COPD patients whose medication was delivered through a DPI were less likely to have medication adherence compared to patients with pMDI, after adjusting for confounding factors, especially active ingredients. Younger groups of patients were less likely to be adherent compared to the oldest group. Smoker men were less likely to be adherent compared to women and non-smokers. Comorbidities decreased the probability of treatment adherence. Those patients that visited their doctor once a month were more likely to adhere to their medication regimen; however, suboptimal adherence was more likely to occur among those patients who visited more than three times per month their doctor. We also found that worsening of COPD is negatively associated with adherence.Conclusion: According to this study, inhaler devices influence patients’ adherence to long-term COPD medication. We also found that DPIs delivering ICS/LABA FDC had a negative impact on adherence. Patients’ clinic and socioeconomic characteristics were associated with adherence. Keywords: adherence, inhaler technique, medication possession ratio (MPR), dry powder inhalers (DPIs), pressurized metered-dose inhalers (pMDIs), persistenc