Japanese Anticholinergic Risk Scale and Domain-Specific Functional Outcomes in Older Poststroke Patients

International anticholinergic burden scales may incompletely capture country-specific prescribing patterns and drug availability. Although the Japanese Anticholinergic Risk Scale (JARS) reflects Japanese clinical practice, its prognostic relevance in poststroke patients remains unclear. We examined whether JARS was associated with functional outcomes across activities of daily living (ADL), cognition, swallowing, nutrition, and muscle strength in older patients after stroke.

This retrospective cohort study enrolled consecutive patients aged ≥ 65 years undergoing poststroke rehabilitation. Anticholinergic burden was assessed using JARS at admission. The primary outcome was Functional Independence Measure (FIM)-motor at discharge. Secondary outcomes were FIM-cognitive, Food Intake Level Scale, Geriatric Nutritional Risk Index (GNRI), and handgrip strength at discharge. Multivariable linear regression was performed for total JARS and, as an exploratory analysis, psychotropic drug-derived JARS, with adjustment for relevant covariates. p-values were adjusted across the five outcomes using the Benjamini-Hochberg false discovery rate (FDR) procedure.

Among 747 patients (median age, 80.0 years; 51% men), 484 (64.8%) had a JARS score of ≥ 1. Total JARS was not associated with discharge FIM-motor score (B = 0.032, 95% CI -0.799 to 0.862), FIM-cognitive score, FILS, or handgrip strength. However, higher total JARS was negatively associated with GNRI at discharge in the primary analysis (B = -0.603; 95% CI, -1.061 to -0.146; FDR-adjusted p = 0.049) although this association did not remain statistically significant in the modified-JARS sensitivity analysis (B = -0.666; 95% CI, -1.179 to -0.154; FDR-adjusted p = 0.055). Psychotropic drug-derived JARS was associated with lower FIM-cognitive score (B = -0.800; 95% CI, -1.318 to -0.282; FDR-adjusted p = 0.013), but not with the other outcomes after FDR adjustment.

JARS was not associated with discharge ADL, swallowing, or muscle strength. A modest association with nutritional risk was observed in the primary analysis, although this finding should be interpreted cautiously because statistical significance was not retained in the modified-JARS sensitivity analysis. Psychotropic drug-derived JARS was associated with cognitive level. These findings support domain- and drug-class-specific interpretation of anticholinergic burden.