May 13, 1996

Characteristics Predicting Incorrect Metered-Dose Inhaler Technique in Older Subjects

Author Affiliations

From the School of Pharmacy, University of North Carolina, Chapel Hill (Drs Gray and Williams and Mr Pulliam); Clinical Research, Glaxo Inc, Research Triangle park, NC (Drs Sirgo and Bishop); and School of Medicine, University of North Carolina, and Department of Medicine, University of North carolina Hospitals, Chapel Hill (Dr Donohue). Dr Gray is now with the School of Pharmacy, University of Washington, Seattle. Deceased.

Arch Intern Med. 1996;156(9):984-988. doi:10.1001/archinte.1996.00440090084008

Objective:  To determine whether cognitive status, hand strength, and demographic variables are predictive of correct use of metered-dose inhalers by older subjects.

Methods:  Clinic patients (n=29) and healthy volunteers (n=42) older than 50 years with no previous or limited metered-dose inhaler use were enrolled. After cognitive Mini—Mental State Examination) and hand strength assessments, subjects received extensive instruction in proper metered-dose inhaler technique. Technique was independently assessed by two evaluators immediately after instruction and 1 week later. Correct technique was defined as (1) activating the canister in the first half of inhalation, (2) continuing to inhale slowly and deeply, and (3) holding breath at full inspiration (5 seconds). Data for the two subject groups were pooled for analyses.

Results:  The mean age of the subjects was 69.77 years. Forty subjects (56%) demonstrated correct metered-dose inhaler technique at 1 week. Logistic regression showed that hand strength measurement (odds ratio, 0.68; 95% confidence interval, 0.55 to 0.84), Mini—Mental State Examination score less than 24 (odds ratio, 3.66; 95% confidence interval, 1.07 to 12.4). and male gender (odds ratio, 5.01; 95% confidence interval, 1.07 to 23.5) were significant predictors of incorrect inhaler use. Correct use of the metered-dose inhaler was unrelated to age, education, or subject status.

Conclusions:  Clinicians should consider cognitive status and hand strength when metered-dose inhaler therapy is initiated for an older adult. Patients with cognitive impairment and hand strength deficits may require more extensive training, frequent follow-up, or alternative dosage forms.(Arch Intern Med. 1996;156:984-988)