The Role of Cognitive Impairment in the Use of the Diskus Inhaler

Abstract Background and Purpose Drugs delivered by metered-dose inhalers and dry powder inhalers (DPIs) are a mainstay in the treatment of chronic lung disease; however, previous studies suggest cognitive impairment hinders proper use of inhalers. The purpose of this study was to determine the relationship between the score on the Mini-Mental State Exam (MMSE) and the ability of nursing facility residents to complete the steps required for proper use of a multiunit-dose DPI (Diskus). Methods Nursing facility residents who had never used a multiunit-dose DPI (Diskus), who scored between 10 and 24 inclusive on the MMSE, and who were able to hold a breath for 10 seconds were recruited for an observational study to test their ability to use a placebo-loaded Diskus when supervised and assisted by personnel trained in the proper use the Diskus. Ability to use the DPI was assessed by the Diskus Evaluation Rating Scale (DERS), an instrument developed specifically for this study. Possible scores on the DERS ranged from 0 to 19, with a score of 0 indicating no limitations in any of the steps involved in using the Diskus and 19 indicating inability to do any of the steps after 3 supervised attempts. Results Forty Diskus-naïve nursing facility residents (86 ± 9 years of age; 32 women) with MMSE scores between 10 and 24 inclusive and the ability to hold a breath for 10 seconds were enrolled in the study. Mean MMSE scores were 17.4 ± 4.2, whereas the mean score on the DERS was 5.1 ± 3.2 (range 1–16). After controlling for age, gender, and education, a significant inverse relationship was noted between scores on the MMSE and the DERS such that for every 1-point increase on the MMSE, the subject's DERS score decreased by 0.345 points ( P = .003). Overall, 38 of the 40 subjects with MMSE scores between 10 and 24 inclusive were able to use the Diskus successfully. Conclusion For MMSE scores, the better the performance on the MMSE, the better the performance on the DERS. More important, 95% of the subjects in this study could use the Diskus successfully when properly supervised. In contrast to earlier studies, these findings suggest that a multiunit-dose DPI can be prescribed as one component of the regimen for chronic lung disease in patients with substantial cognitive impairment.