Self-reported inhaler use in patients with chronic obstructive pulmonary disease.

COPD is a common disease which is increasing in prevalence. The proportion of patients who vary their inhaler use from what is prescribed and the reasons for variance are largely unknown. The objective of this study was to determine the extent of and reported reasons for patient-reported variance in the use of inhalers prescribed for COPD. A 17-item survey was mailed to 600 ambulatory patients with spirometry-defined COPD. The survey included questions about inhaler use and reasons for using inhalers differently than prescribed. Survey responses were compared between patients reporting no variance vs. variance from prescribed instructions. Logistic regression was used to determine predictors for variance. The response rate was 45.8% (48.7% male; mean age: 73+/-8 years). Forty percent of respondents were not using inhalers as prescribed. The most common reasons were: feeling the inhalers did not help breathing (20%), forgetting to use inhalers (19%) and cost (15%). Higher education level, home oxygen use and prescriptions for ipratropium were predictors for inhaler variance. The impact of inhaler variance on morbidity of COPD should be evaluated.