Metered dose inhaler technique among inner-city asthmatics and its association with asthma medication adherence

Introduction: Inhaled medications, critical for asthma treatment, are self-administered through metered dose inhalers (MDI). Asthma self-management hinges on adherence to these medications and to proper MDI technique. Objective: To assess predictors of proper MDI technique, and MDI technique as a tool to identify patients with low adherence to inhaled medications. Methods: Prospective cohort of asthmatics from clinics in New York, NY and New Brunswick, NJ. MDI technique was assessed using a standardized checklist. Adherence to inhaled asthma controller medication was evaluated with the Medication Adherence Report Scale. Predictors of MDI technique were evaluated using regression analyses. The distribution of number of MDI technique steps missed was compared in adherent vs. non-adherent asthmatics. Results: Overall, 326 patients were included (55% Hispanic, 27% Black). In adjusted analyses, age<55 years was significantly associated with MDI technique (P=0.03). Overall, 12%, 34%, 40% of asthmatics missed 5-6, 3-4, or 1-2 MDI steps; 16% received a perfect MDI technique score. Adherence rates were 20%, 39%, 48%, and 62% among those who missed 5-6, 3-4, 1-2, or none of the steps in the MDI technique checklist (P<0.001). Conclusion: Poor MDI technique is common among inner-city patients with asthma and is associated with poor adherence to controller medications. Older patients with asthma are at higher risk of improper MDI technique. Assessment of MDI technique may be a simple clinical aid to identify patients with low adherence to controller medications.