Inhaler device, administration technique and adherence to inhaled corticosteroids among asthmatics

Background. Inhaled corticosteroids (ICS), the mainstay treatment for persistent asthma, are available in different types of devices, including metered dose inhalers (MDI) and dry powder inhalers (DPI). Although use of these devices requires different sets of skills, there is no data regarding the influence of type of device on self-management behavior.;Objective. To compare ICS inhaler type with user technique and ICS medication adherence.;Methods. We surveyed 326 adults with persistent asthma who received care at 2 inner-city outpatient clinics. The 270 patients on ICS were classified into two groups according to the type of ICS device: MDI or DPI. We used standardized checklists to assess the patient's inhaler technique. Medication adherence was evaluated using the Medication Adherence Report Scale (MARS), a validated self-report measure. Univariate and multiple regression analyses were conducted to evaluate differences in inhaler technique and MARS score among patients using MDIs versus DPIs.;Results. Overall, 60% of patients used a DPI and 40% MDI for their ICS. Univariate analysis showed no difference in technique scores among 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 1.2-3.8) but not with inhaler technique (Beta: -0.2; 95% CI -0.5, 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 further elucidate the potential effect of the type of ICS delivery device on asthma self-management.