Evaluation of the use of inhaled medications by hospital inpatients with chronic obstructive pulmonary disease.

Background: The prevalence of chronic obstructive pulmonary disease (COPD) is increasing. Patients with COPD are treated with a variety of inhaled medications. Previous studies evaluating inhaler technique have had varied results but have generally found high rates of misuse of these devices. There is a paucity of studies of inhaler technique focusing on North American patients with COPD who have been admitted to hospital.

Objective: To evaluate the inhaler technique of patients with COPD who have been admitted to hospital and to identify baseline patient characteristics and/or inhaler devices associated with poor inhaler technique.

Methods: Patients with a diagnosis of COPD who were admitted to the hospitalist or internal medicine service at a tertiary care hospital in British Columbia between October 2010 and April 2011 were identified. After giving informed consent, recruited patients demonstrated their inhaler technique, which was evaluated with standardized checklists. Errors in technique were categorized as either noncritical or critical. Critical errors were defined as those resulting in little or no medication reaching the lungs.

Results: Thirty-seven patients (mean age 78 years) participated in the study. Twenty-two (59%) of the patients made critical errors while demonstrating their inhaler technique. Patients using metered-dose inhalers were more likely to make a critical error than patients using other inhalers (13/14 [93%] versus 9/23 [39%]; relative risk 2.38, p = 0.002). On average, 26% of the steps for using an inhaler were performed incorrectly. Twenty-three (62%) of the patients reported having received previous counselling on inhaler technique, but only 13 (57%) of these 23 patients had received such counselling in the previous 6 months.

Conclusions: More than half of the patients in this study misused their inhaler devices, and many made critical errors that would result in inadequate amounts of drug reaching the lung. Many of the patients were not receiving regular counselling on appropriate inhaler technique. Health care professionals should be aware of poor inhaler technique, should routinely evaluate their patients' inhaler technique, and should provide counselling.