Anticholinergic medications are widely prescribed in older adults and contribute to cumulative anticholinergic burden, which has been associated with cognitive decline, falls, and frailty. The Anticholinergic Cognitive Burden (ACB) scale is commonly used to quantify this burden;[1,2] however, it does not include many drugs frequently prescribed in Japan. To address this limitation, the Japanese Anticholinergic Risk Scale (JARS), a Japan-specific adaptation of the ACB scale, was recently developed in 2024.
Despite increasing recognition of anticholinergic burden, its impact on lower urinary tract function, particularly voiding dynamics, remains incompletely understood. While anticholinergic medications are often assumed to increase postvoid residual (PVR) urine volume, their effect on voiding efficiency has not been well characterized. The present study aimed to evaluate the association between anticholinergic burden, assessed using JARS, and objective voiding parameters in older adults.

This cross-sectional study included residents of long-term care facilities (geriatric health services facilities) between 2019 and 2022. Anticholinergic burden was quantified using the JARS score.

Voided volume was measured using a urine collection cup at each voiding episode, and postvoid residual (PVR) volume was assessed using a portable uroflowmetry device (Lilium®) or ultrasonography. Voided volume and PVR were each measured three times, and the mean values were used for analysis. Voiding efficiency was calculated as voided volume divided by total bladder volume (voided volume + PVR).

Associations between JARS score and continuous voiding parameters were evaluated using multivariable linear regression adjusted for age and body mass index (BMI). Logistic regression analyses were performed to assess clinically relevant outcomes, including decreased voiding efficiency (<50%) and elevated PVR (>100 mL). Sensitivity analyses using median-based thresholds were also conducted.

A total of 197 participants were included. The mean age was 87.3 ± 9.0 years, and 72.0% were female. The mean number of medications was 5.7 ± 2.9. The mean voided volume was 134.3 ± 85.8 mL, mean PVR was 109.5 ± 94.1 mL, and mean voiding efficiency was 56.8 ± 21.5%. The mean JARS score was 1.41 ± 1.65 (median 1.0).

 In multivariable linear regression analyses, JARS score was not significantly associated with voided volume, PVR, or voiding efficiency. However, logistic regression analysis demonstrated that higher JARS scores were significantly associated with decreased voiding efficiency (<50%) (odds ratio [OR] 1.25, p = 0.024). This association remained significant in sensitivity analyses using median-based thresholds (OR 1.23, p = 0.044). In contrast, no significant association was observed between JARS score and elevated PVR (>100 mL) (OR 1.11, p = 0.298).

In this cohort of older adults residing in long-term care facilities, anticholinergic burden was associated with impaired voiding efficiency but not with increased postvoid residual urine volume. These findings suggest that anticholinergic medications may disrupt coordinated bladder emptying rather than simply causing urinary retention.

The lack of association with PVR, even at a clinically relevant threshold of 100 mL, indicates that conventional measures of urinary retention may underestimate the functional impact of anticholinergic burden on voiding. The consistent association observed across multiple analytical approaches, including median-based sensitivity analyses, further supports the robustness of these findings.

Anticholinergic burden in older adults is associated with impaired voiding efficiency rather than increased residual urine volume. Assessment of voiding efficiency, in addition to postvoid residual, may therefore be important when evaluating voiding dysfunction in this population.

Boustani M, Campbell N, Munger S, Maidment I, Fox C. Impact of anticholinergics on the aging brain: a review and practical application. J Am Geriatr Soc. 2008;56(3):507–514.
Campbell NL, Boustani MA, Lane KA, et al. Use of anticholinergics and the risk of cognitive impairment in an African American population. Neurology. 2010;75(2):152–159.