Anticholinergic and central nervous system‐active drug burdens and their associations with adverse in‐hospital outcomes among older inpatients

Aim Anticholinergic (ACh) and central nervous system (CNS)‐active drug burdens may be associated with adverse outcomes in older adults. This study assessed these burdens and examined their associations with adverse in‐hospital outcomes. Methods A retrospective cross‐sectional analysis was conducted among 13 607 hospitalizations in patients aged ≥60 years in 2024. ACh burden was assessed using the 2022 CRIDECO Anticholinergic Load Scale, and the 2023 Beers Criteria were used to assess CNS‐active burden. For each exposure, hospitalizations were classified as having no, low, or high burden. The primary outcome was a composite of delirium, cognitive impairment, falls or fractures. Secondary outcomes included length of stay, in‐hospital mortality and hospitalization costs. Separate multivariable regression models were used to estimate associations with ACh and CNS‐active burdens. Results Low and high ACh burdens were identified in 30.24% and 63.65% of hospitalizations, respectively; the corresponding proportions for CNS‐active burden were 49.17% and 21.99%. Compared with no ACh burden, high ACh burden was associated with the primary outcome (adjusted odds ratio aOR 8.40; 95% confidence interval CI 3.46–20.38), whereas low ACh burden was not. Compared with no CNS‐active burden, both low (aOR 4.67; 95% CI 2.67–8.18) and high (aOR 32.64; 95% CI 19.06–55.89) CNS‐active burdens were also associated with this outcome. High burden in either group was associated with longer hospital stay, higher mortality and greater costs. Conclusions ACh and CNS‐active burdens were associated with adverse in‐hospital outcomes, supporting consideration of routine inpatient medication reviews to identify potentially harmful cumulative drug burden.