Anticholinergic Exposure During Rehabilitation: Cognitive and Physical Function Outcomes in Patients with Delirium Superimposed on Dementia

Objectives: We examined the association between anticholinergic medication exposure and subsequent cognitive and physical function in patients with delirium superimposed on dementia during rehabilitation. We also examined length of stay and discharge disposition by anticholinergic medication exposure. Design: In this secondary analysis we used control group data from an ongoing randomized clinical trial. Setting/Participants: Participants with delirium and dementia were enrolled at admission to post-acute care. These 99 participants had a mean age of 86.11 (+/- 6.83) years; 67.6% were women; 98% were Caucasian; and 33% were positive for at least one APOE e4 allele. Measures: We obtained daily measures of cognitive and physical function using: Digit Span; memory, orientation and attention items from the Montreal Cognitive Assessment; CLOX; the Confusion Assessment Method; and the Barthel Index. Anticholinergic medication exposure was measured weekly using the Anticholinergic Cognitive Burden Scale. Results: Using multilevel models for time we found that greater use of clinically relevant anticholinergic medications in the previous week reduced cognitive and physical function, as measured by Digit Span Backwards and the Barthel index, in the current week. There was no effect of anticholinergic medication use on delirium severity, and APOE status did not moderate any outcomes. Greater use of clinically relevant anticholinergic medications was related to longer length of stay but not discharge disposition. Conclusions: For vulnerable older adults, anticholinergic exposure represents a potentially modifiable risk factor for poor attention, working memory, physical function, and greater length of stay during rehabilitation.