Anticholinergic medication use and falls in Australian residential aged care: a retrospective multisite cohort study

Associations between anticholinergic load and falls remain understudied in residential aged care facilities (RACFs).

To examine associations between anticholinergic load and falls in the first year after entry to an RACF.

We aggregated routinely collected data from 27 RACFs in New South Wales, Australia. Anticholinergic load and falls were repeatedly measured for one year after residents first entered an RACF. Thirteen 28-day review periods were set. Associations between anticholinergic load in a review period and any falls in the next review period were examined, comprising 12 repeated measurements of associations. We included new residents aged ≥ 65 years, who entered an RACF between 1 July 2014 and 2 September 2021. Six scales were used: Anticholinergic Cognitive Burden (ACB), Anticholinergic Drug Scale (ADS), Anticholinergic Loading Scale (ALS), Anticholinergic Risk Scale (ARS), Chew's list, and Clinician-rated Anticholinergic Score (CrAS). We used mixed-effect logistic regression models, adjusting for potential confounders. Facility was used as a cluster variable.

For the 2300 residents (67.7% females), there were steady increases in mean anticholinergic load from the first to the 12th review period. Per one-point higher anticholinergic load was associated with an increased risk of falls, adjusted odds ratios: 1.08 (95% confidence interval[CI] 1.04, 1.12) using ACB, 1.11 (95%CI 1.06, 1.15) using ADS, 1.15 (95%CI 1.10, 1.21) using ALS, 1.10 (95%CI 1.04, 1.17) using ARS, 1.18 (95%CI 1.09, 1.27) using Chew's list, and 1.14 (95%CI 1.10, 1.19) using CrAS.

Anticholinergic scales may be useful to inform falls prevention programs for new RACF residents.