Aim: To compare inhaled corticosteroid (ICS) inhaler type with user technique and ICS medication adherence among adults with asthma.
Methods: We classified 270 adults into two groups by ICS device type: metered-dose inhaler (MDI) or dry powder inhaler (DPI). Inhaler technique was assessed using standardised checklists. Medication adherence was evaluated using the Medication Adherence Report Scale (MARS). Differences in inhaler technique and MARS score among patients using MDIs versus DPIs were evaluated.
Results: Univariate analysis showed no difference in technique scores between the groups (p=0.46), but better ICS adherence among DPI users (p=0.001). In multivariable analysis, DPI use remained significantly associated with higher rates of adherence (OR 2.2; 95% CI 1.2 to 3.8) but not with inhaler technique (-0.2; 95% CI -0.5 to 0.1) after adjusting for potential confounders.
Conclusions: Type of inhaler device appears to be associated with adherence to asthma controller medications. Prospective studies are needed to elucidate further the potential effect of the type of ICS delivery device on asthma self-management.