Characteristics of reversible and nonreversible COPD and asthma and COPD overlap syndrome patients: an analysis of salbutamol Easyhaler data

Abstract

The choice of inhaler device for bronchodilator reversibility is crucial since suboptimal inhalation technique may influence the result. On the other hand, bronchodilator response also varies from time to time and may depend on patient characteristics. In this study, patients with airway obstruction (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ratio <70% in chronic obstructive pulmonary disease [COPD]; <80% in asthma) were included (n=121, age: 57.8+/-17.3 years). Bronchodilator reversibility (American Thoracic Society/European Respiratory Society criteria) was tested in patients with COPD (n=63) and asthma and COPD overlap syndrome (ACOS; n=12). Forty-six asthmatics served as controls. Reversibility was tested with 400 microg salbutamol dry powder inhaler (Buventol Easyhaler, Orion Pharma Ltd, Espoo, Finland). Demographic data and patients' perceptions of Easyhaler compared with beta2-agonist pressurized metered dose inhalers (pMDIs) were analyzed. American Thoracic Society/European Respiratory Society guideline defined reversibility was found in 21 out of 63 COPD patients and in two out of 12 ACOS patients. Airway obstruction was more severe in COPD patients as compared with controls (mean FEV1 and FEV1% predicted both P<0.0001). Average response to salbutamol was significantly lower in COPD patients compared with asthma controls (P<0.0001). Reversibility was equally often found in smokers as in never-smokers (33% vs 34%). Nonreversible COPD patients had higher mean weight, body mass index, and FEV1/FVC compared with reversible COPD patients. Most patients preferred Easyhaler and defined its use as simpler and more effective than use of a pMDI. Never-smokers and patients with asthma experienced Easy-haler somewhat easier to use than smokers and patients with COPD. In conclusion, a substantial part of patients with COPD or ACOS showed reversibility to salbutamol dry powder inhaler. Nonreversible patients with COPD were characterized by higher weight and body mass index, and a higher FEV1/FVC ratio. Most patients preferred Easyhaler compared with a pMDI.