The influence of type of inhalation device on adherence of COPD patients to inhaled medication

Objective: To study the influence of type of inhalation device on adherence of COPD patients to inhaled medication. Methods: Therapy adherence of 795 patients was recorded from pharmacy records over 3 years. It was expressed as percentage and was deemed good at 75–125%, sub-optimal 50-75%, and poor <50% or >125%. Some patients used more than one medication, so we present 1377 medication periods. Results: Patients using a Cyclohaler have a 7-fold increased risk of suboptimal adherence versus good adherence compared to the Handihaler; for Metered Dose Inhaler (MDI) and Diskus 2.3 and 2.2 times as high, respectively. (table 1) Patients using a MDI, Diskus or Autohaler have a 2.0; 2.2 and 6.8-fold increased risk of poor <50% versus good adherence compared to a Handihaler. Patients using a MDI, Autohaler, Turbuhaler or Cyclohaler have an increased risk of poor (>125%) versus good adherence compared to a Handihaler. Table 1: Nominal regression of device vs therapy adherence. Good adherence and Handihaler are set as reference. Corrected for FEV1 at baseline. 50-75% n=209 Odds 95% CI FEV1 baseline 1.1 0.8-1.4 1. MDI 2.3 1.5-3.4 2. Diskus 2.2 1.4-3.4 3. Respimat 1.6 0.9-2.9 4. Autohaler 1.0 0.1-8.4 5. Turbuhaler 1.2 0.6-2.3 6. Cyclohaler 7.0 1.9-25.0 <50% n=115 FEV1 baseline 1.5 1.1-2.1 1 2.0 1.2-3.4 2 2.2 1.3-3.7 3 0.99 0.4-2.3 4 6.8 1.9-24.6 5 1.1 0.5-2.6 6 - - >125% n=145 FEV1 baseline 0.6 0.4-0.9 1 3.5 2.1-6.0 2 1.7 0.9-3.3 3 2.0 0.95-4.3 4 7.0 1.7-29.0 5 7.9 4.3-14.4 6 10.7 2.4-48.1 Conclusi