EVALUATION OF THE EFFECTIVENESS OF 4 DIFFERENT INHALERS IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

Background - The percentage of patients inhaling their medication effe ctively varies widely, according to methods of assessment and inhalers used. This study was carried out to assess differences among four typ es of inhalers using inhaler-specific checklists. Methods - Inhalation technique was evaluated in adult patients with chronic obstructive pu lmonary disease (COPD). Inhalers investigated were either metered dose inhalers (MDIs) or the dry powder inhalers Turbohaler (Turbuhaler), D iskhaler, and Rotahaler. Errors were recorded against inhaler-specific checklists. From these, scores were derived by dividing the number of items correctly completed by the total number of items on the checkli st and the result was expressed as a percentage. For every inhaler ((e ssential actions') were identified and scores on these key manoeuvres were calculated. The percentage of patients performing all these essen tial actions correctly was also calculated. Scores were also compared with adjustment for differences in relevant patient characteristics. R esults - Important differences among inhalers were found. Of 152 patie nts with COPD (mean (SD) age 55.1 (8.7) years), those with MDIs perfor med worst, especially when only essential items were considered. Patie nts with a Diskhaler did best, although after correction for patient c haracteristics the differences tended to diminish. Only 60% of patient s were able to perform all essential inhaler actions satisfactorily. O f those using the Diskhaler, 96% did so correctly, while the correspon ding figure for those using the MDI was only 24%. Conclusions - Many p atients with COPD use their inhaler ineffectively. After adjusting for patient characteristics, differences among inhalers, although less pr onounced, persist. Patients using a Diskhaler made fewest errors, whil e most patients using MDIs made crucial mistakes.