Prevalence and predictors of anticholinergic agents in elderly outpatients with dementia.

Background: Anticholinergic medications, although frequently used in elderly populations, are associated with cognitive impairment and constitute significant concern for patients with dementia.

Objective: The purpose of our study was to examine patterns and predictors of prescribing anticholinergic agents for elderly outpatients with dementia.

Methods: We combined data from the 2006-2007 National Ambulatory Medical Care Survey and the outpatient department component of National Hospital Ambulatory Medical Care Survey to analyze patient visits by elderly persons (aged ≥65 years) with dementia. Anticholinergic drugs were identified using the Anticholinergic Drug Scale, which classifies anticholinergic drugs into four levels (0-3) in increasing order of anticholinergic activity. Descriptive analysis using sampling weights was used to evaluate patterns of anticholinergic drug prescription, especially prescribing of medications with clinically significant anticholinergic activity (ie, levels 2 or 3). Multiple logistic regression was used in the conceptual framework of the Andersen Behavioral Model to examine the predisposing, enabling, and need factors associated with prescribing of medications with clinically significant anticholinergic activity.

Results: According to the national surveys there were a total of 6.8 million (95% CI, 5.27-8.44 million; 0.32%) ambulatory care visits for dementia. Approximately 43% (42.86%; 95% CI, 35.24-50.48) of these visits involved prescribing at least one anticholinergic drug; and 10.07% of visits involved prescribing levels 2 or 3 anticholinergic medications. The predisposing factor, age (75-84 years; odds ratio [OR] = 0.25; 95% CI, 0.07-0.87), and the need factors, acetylcholinesterase inhibitor use (OR = 0.25; 95% CI, 0.07-0.86) and comorbid mood disorders (OR = 0.12; 95% CI, 0.02-0.73), were associated with decreased likelihood of prescribing medications with clinically significant anticholinergic activity. The need factor total number of medications prescribed (OR = 1.45, 95% CI, 1.20-1.75) increased the likelihood of these prescriptions being administered.

Conclusions: One in 10 outpatient visits by elderly persons with dementia involved prescribing medications with clinically significant anticholinergic activity. Given their adverse cognitive effects, there is a strong need to optimize anticholinergic drug prescribing in vulnerable elderly outpatients with dementia.