The influence of mixing inhaler devices on inhaler technique in COPD

Introduction: Mixing inhaler devices requiring different techniques has an adverse effect on COPD outcomes suggesting that it leads to inappropriate inhaler technique, however, empirical evidence is lacking. Aims: Compare the nature and frequency of inhaler technique errors in COPD patients prescribed with (1) a single dry powder inhaler (DPI) versus those with (2) mixed-devices [a DPI and pressurized metered dose inhaler (pMDI)]. Methods: Balanced 1:1 matching was applied, based on country of residence and DPI device type, to score DPI technique errors in patients using (1) a single DPI (n=291) or (2) DPI + pMDI (n=291). Pre-determined checklists were used for the evaluation of DPI video recordings and complemented with errors that were observed in ≥10% of patients. Results: DPI technique errors were common in both groups. Errors ‘exhalation through the device before inhalation’ and ‘no breath-hold (<6 sec.)’ were more likely to occur in the mixed-devices group (Odds Ratio: 2.30 [1.03;5.14] & 1.71 [1.15;2.54], resp. Fig 1). Conclusion: Patients with COPD reveal poor inhaler technique – currently, ‘pMDI-related errors’ in DPI use are not accounted for in existing checklists. Although in general odds ratios pointed to more errors in the mixed-devices group, the nature and frequency of errors did not significantly differ between patients using a single DPI or mixed-devices.