UC Irvine

Importance: There are approximately 3.5 million people aged 90+ in the United States; they are the fastest growing segment of the aging population. The cognitive health complications facing the oldest-old are unique in complexity. Many medications have anticholinergic properties; the general view is that anticholinergic-induced cognitive impairment is reversible upon drug discontinuation. Studies suggest that anticholinergic use is associated with dementia risk in the younger-old (65-75 years). It is not clear if these relationships persist in advanced age.

Objective: To examine weather anticholinergic use is associated with risk of incident dementia in people aged 90+.

Design: Prospective population-based cohort using data from the participants of the 90+ Study.

Participants: We studied 704 participants without dementia. We also examined dementia risk between individuals with normal or abnormal cognition.

Exposure: Anticholinergic use was assessed at baseline. The Cerner Multum™Lexicon database and The American Geriatrics Society (AGS) 2015 Beers Criteria were used to classify medications.

Outcome Measures: Incident dementia using standardized diagnostic criteria. We used multivariable Cox-proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) using age as the time scale.

Results: There was no significant risk of dementia associated with anticholinergic use after adjustment for education, diabetes, stroke and heart disease (HR=0.997, 95% CI:0.737-1.349) among individuals aged 90+. Similarly, no associations were found when analyses were restricted to individuals with abnormal (HR=0.998, 95%CI:0.693-1.437) or normal cognition (HR=0.690, 95%CI:0.353-1.346) at baseline.

Conclusion: Use of anticholinergic medication does not appear to be associated with risk of dementia in the oldest-old.