Background and objective: Mixed inhaler device use for asthma is associated with worse inhaler technique and outcomes. Given that relievers are commonly prescribed as pressurized metred-dose inhalers (pMDI), changing preventers from dry powder inhalers (DPI) to pMDI may improve asthma outcomes. This study aimed to assess the persistence and effectiveness of switching from DPI to pMDI for inhaled corticosteroid and long-acting β2 -agonist combination therapy (ICS/LABA).
Methods: This was a historical cohort study using Ajou University Hospital (Korea) patient records. Persistence of switch was defined as receiving ≥1 pMDI and no DPI after the switch. Effectiveness of switch was assessed as the proportion without severe asthma exacerbation and the proportion achieving risk domain asthma control (RDAC; no asthma-related hospitalization, antibiotics without upper respiratory diagnosis or acute course of oral corticosteroids) and overall asthma control (OAC; RDAC and ≤ 200 μg salbutamol/≤500 μg terbutaline average daily dose) comparing 1 year after and before the switch.
Results: Within 85 patients who switched from DPI to pMDI and persisted for a year, higher proportion were free from asthma exacerbation after the switch (mean difference in proportion = 0.129, 95% CI: 0.038-0.220). Switching to pMDI was also associated with better RDAC (75.3% vs 57.7%, P = 0.001) and OAC (57.7% vs 45.9%, P = 0.021). From the entire 117 patients who switched to fixed-dose combination (FDC)/ICS LABA pMDI, 76.1% (95% CI: 69.0-100.0%) patients persisted in the following 6 months.
Conclusion: Switching to and persisting with pMDI was associated with decreased asthma exacerbations and improved asthma control. The majority of patients persisted with the switch to pMDI for ICS/LABA treatment.
Keywords: asthma; dry powder inhaler; medication persistence; metred-dose inhaler; treatment efficacy.
© 2019 Asian Pacific Society of Respirology.