Anticholinergic Burden in Older Adult Inpatients: Patterns from Admission to Discharge and Associations with Hospital Outcomes

M Herrero-Zazo , E Bines , R Berry , D Bhattarcharya , Phyo K Myint, VL Keevil * (Corresponding Author)

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

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Background: Anticholinergic medications are associated with adverse outcomes in older adults and should be prescribed cautiously. We describe the Anticholinergic Risk Scale (ARS) scores of older inpatients and associations with outcomes.

Methods: We included all emergency, first admissions of adults ⩾65 years old admitted to one hospital over 4 years. Demographics, discharge specialty, dementia/history of cognitive concern, illness acuity and medications were retrieved from electronic records. ARS scores were calculated as the sum of anticholinergic potential for each medication (0 \u003d limited/none; 1 \u003d moderate; 2 \u003d strong and 3 \u003d very strong). We categorised patients based on admission ARS score [ARS \u003d 0 (reference); ARS \u003d 1; ARS \u003d 2; ARS ⩾ 3] and change in ARS score from admission to discharge [admission and discharge ARS \u003d 0 (reference); same; decreased; increased]. We described anticholinergic prescribing patterns by discharge specialty and explored multivariable associations between ARS score categories and mortality using logistic regression [odds ratios (ORs), 95% confidence intervals (CIs)].

Results: From 33,360 patients, 10,183 (31%) were prescribed an anticholinergic medication on admission. Mean admission ARS scores were: Cardiology and Stroke \u003d 0.56; General Medicine \u003d 0.78; Geriatric Medicine \u003d 0.83; Other medicine \u003d 0.81; Trauma and Orthopaedics \u003d 0.66; Other Surgery \u003d 0.65. Mean ARS did not increase from admission to discharge in any specialty but reductions varied significantly, from 4.6% (Other Surgery) to 27.7% (Geriatric Medicine) (p \u003c 0.001). The odds of both 30-day inpatient and 30-day post-discharge mortality increased with admission ARS \u003d 1 (OR \u003d 1.21, 95% CI 1.01–1.44 and OR \u003d 1.44, 1.18–1.74) but not with ARS \u003d 2 or ARS ⩾ 3. The odds of 30-day post-discharge mortality were higher in all ARS change categories, relative to no anticholinergic exposure (same: OR \u003d 1.45, 1.21–1.74, decreased: OR \u003d 1.27, 1.01–1.57, increased: OR \u003d 2.48, 1.98–3.08).

Conclusion: The inconsistent dose–response associations with mortality may be due to confounding and measurement error which may be addressed by a prospective trial. Definitive evidence for this prevalent modifiable risk factor is required to support clinician behaviour-change, thus reducing variation in anticholinergic deprescribing by inpatient speciality.
Original languageEnglish
Pages (from-to)1-13
Number of pages13
JournalTherapeutic Advances in Drug Safety
Early online date6 May 2021
Publication statusPublished - 2021

Bibliographical note

The authors would like to thank the clinical informatics team at Cambridge University’s Hospital for their help in data extraction from the EHR.

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: VLK is funded by a Medical Research Council (MRC)/National Institute for Health Research (NIHR) Clinical Academic Research Partnership grant (CARP; grant code: MR/T023902/1). MHZ acknowledges support from the NIHR Cambridge Biomedical Research Centre (BRC-1215-20014). The views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care or the MRC


  • anticholinergic medication
  • deprescribing
  • mortality
  • older adults


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