Prevalence and predictors of anticholinergic medication use in elderly nursing home residents with dementia: analysis of data from the 2004 National Nursing Home Survey.

BACKGROUND

Medications with anticholinergic properties are frequently used in the elderly population. However, evidence suggests that these medications are associated with significant adverse effects and may lead to worsening of cognitive impairment, particularly in elderly patients with dementia.

OBJECTIVE

To examine the utilization of anticholinergic medications and factors associated with anticholinergic medication use in elderly nursing home patients with dementia.

METHODS

The study examined anticholinergic medication utilization for patients aged ≥65 years with dementia, using the 2004 US National Nursing Home Survey (NNHS) data. Anticholinergic drugs were identified using the Anticholinergic Drug Scale (ADS), which classifies anticholinergic drugs into four levels in increasing order of their anticholinergic activity. Descriptive analysis was conducted using sampling weights to determine the prevalence of anticholinergic medication use. Multiple logistic regression within the conceptual framework of the Andersen Behavioral Model was used to examine the factors associated with anticholinergic medication use in the study population. Use of medications with marked anticholinergic activities (ADS level 2 or 3) was the dependent variable, and independent variables were the various predisposing, enabling and need factors.

RESULTS

According to the 2004 NNHS, 509,931 (95% CI 490,160, 529,702) or 73.62% (95% CI 72.23, 75.00) of elderly patients with dementia used anticholinergic medications. The highest prevalence of anticholinergic medication use among elderly patients with dementia was seen for level-1 medications (67.96%; 95% CI 66.51, 69.41), and 21.27% (95% CI 19.93, 22.60) used ADS level-2 or level-3 medications. Multivariate regression analysis showed that the predisposing factor of age was negatively associated with the use of medications with marked anticholinergic activities (ADS level 2 or 3) and the enabling factor of Medicaid as the source of payment increased the likelihood of receiving these higher-level anticholinergics. Among the need factors, dependence in decision-making ability and behavioural symptoms decreased the likelihood of receiving higher-level anticholinergics, whereas factors such as total number of medications, depressed mood indicators and diagnoses of schizophrenia, anxiety and Parkinson's disease increased the likelihood of use of such medications.

CONCLUSIONS

Over one in five elderly nursing home residents with dementia used medications with marked anticholinergic activities. The study findings suggest the need to optimize the use of anticholinergic medications in vulnerable patients with dementia given the potentially severe adverse cognitive effects of these agents.