Cognitive Impairment by Montreal Cognitive Assessment Independently Predicts Incorrect Inhaler Use Among Patients with Chronic Obstructive Pulmonary Disease

Objectives: To investigate correct inhaler use in COPD patients compared among immediately after, and one month after inhaler use training, and to identify independent predictors of incorrect inhaler use at 1 month after training.Methods: This prospective study was conducted at COPD clinic, Siriraj Hospital (Bangkok, Thailand). Patients demonstrated improper inhaler use were trained face-to-face by pharmacists, and then assessed immediately after and at 1 month after training. Results: A total of 254 COPD patients (446 devices) were assessed. Incorrect technique in any step was found in 119(46.9%) patients. Sixty-six patients (101 devices) with at least one critical error in any one controller inhaler were enrolled. Mean age was 73.0±9.0 years, and 50(75.8%) patients had moderate/severe COPD. Immediately after training, all patients correctly performed all dry powder inhalers, and 88.1% correctly performed pressurized metered-dose inhaler. At 1 month, correct inhalation technique was decreased in all devices. Multivariate analysis revealed a Montreal Cognitive Assessment (MoCA) score £16 to be independently associated with a critical error at 1 month after training (adjusted odds ratio: 13.3, 95% confidence interval: 1.9-93.7; p =0.009). At 1 month, quality of life (CAT) was significantly improved (11.4±8.9 vs 8.4±5.5, p =0.018) and met minimal clinically important difference (MCID) in patients with correct technique.Conclusions: Face-to-face inhaler use training by a pharmacist improves patient performance. However, proper technique was decreased at one month, and cognitive impairment (MoCA score £16) was independently predict improper inhaler use. Cognitive function assessment, technique recheck, and repeated training should improve COPD treatment outcome.