Temporal Trends of Anticholinergic Drug Exposure Among Older Adults: A 25-Year Population-Based Study

Exposure to anticholinergic drugs is associated with adverse outcomes, particularly among older adults. Limiting the anticholinergic burden (ACB) among older patients has been advocated for decades, but reliable population-level data on temporal trends are lacking. Here, we estimated the cumulative incidence and incidence rates (IRs) of a cumulative ACB score of three or more (cACB ≥ 3) among older adults in a community-dwelling population and described the changes in IR over the past 25 years.

Within the population-based Rotterdam Study, pharmacy dispensing records were obtained from 11,038 individuals aged 65+ years from 1996 to 2020. The cACB score was calculated with the Anticholinergic Cognitive Burden Scale and supplemented with drugs on the ACB scale by the Expertisecentre PHarmacotherapy in OldeR people (EPHOR). Age- and sex-specific IRs were calculated, and non-overlapping 5-year episodes were defined to determine time trends in IRs.

The cumulative incidence of a cACB ≥ 3 was 25.3% between 1996 and 2020. Compared with 1996-2000, the IR of cACB ≥ 3 had declined by 54% between the 2016-2022 episode (IR ratio: 0.46, 95% confidence interval (CI): 0.41-0.52). Participants aged 86-90 years had more than 1.5 times the rate of a cACB ≥ 3 compared with participants aged 66-70 years (IR ratio: 1.67, 95% CI 1.46-1.91).

Exposure to anticholinergic drugs has decreased by over 50% between 1996 and 2020 in this population of community-dwelling adults. However, the oldest old had and remained to have the highest risk of a cACB ≥ 3 during our study period. Thus, prescribers and pharmacists should continue to regularly review the prescription of drugs with an ACB, especially among those vulnerable to adverse outcomes.