A Mediation Analysis Examining High Risk, Anticholinergic Medication Use, Delirium, and Dementia After Major Surgery

Area of Science:

• Geriatric Medicine
• Neuroscience
• Pharmacology

Background:

• Anticholinergic medications are known to cause cognitive impairment in older adults.
• The use of these medications in major surgery patients and their link to delirium and dementia is not well understood.

Purpose of the Study:

• To determine the prevalence of high-risk anticholinergic medication use in patients undergoing major surgery.
• To investigate the relationship between anticholinergic use, delirium, and the development of dementia post-surgery.

Main Methods:

• Retrospective cohort study of 39,665 patients over 50 undergoing inpatient surgery (2013-2019).
• Primary exposure: doses of anticholinergic medications during hospitalization.
• Primary outcome: new diagnosis of dementia at 1-year post-surgery. Analyzed using regression and mediation analysis.

Main Results:

• 91% of patients received anticholinergic medications; 19.1% received six or more doses.
• High anticholinergic doses were associated with increased odds of dementia at 1-year (OR 2.7).
• Postoperative delirium mediated 57.6% of the association between anticholinergic medications and dementia.

Conclusions:

• High-dose anticholinergic use is prevalent in major surgery patients.
• Anticholinergic medications are associated with a higher risk of developing dementia, partly mediated by delirium.
• Strategies to reduce anticholinergic use may improve cognitive outcomes after surgery.