Deliriogenic Medication Prescribing and Delirium in Hospitalized, Non-Critically Ill Older People

Objective Describe the incidence of delirium and associated outcomes among hospitalized, non-critically ill older people. Design Single-center, retrospective chart review. Setting A 217-bed academic teaching hospital in Cambridge, Massachusetts affiliated with Harvard Medical School. Patients People 65 years of age or older, admitted to a general medicine unit between January 1 and August 31, 2021, who were prescribed one or more deliriogenic medications prior to or during admission. Interventions Patient electronic medical records were reviewed for deliriogenic medications prescribed and administered during admission and associated clinical outcomes. Results The percentage of patients who developed delirium was 13% overall. The most implicated deliriogenic medications were benzodiazepines, antipsychotics, and histamine-2 receptor antagonists (H2RAs). Seventy-three percent of deliriogenic home medications were continued upon admission. Subgroup analyses of those with delirium had a mean length-of-stay of 20 days compared with 6 days in those who did not develop delirium. Those with delirium tended to have more deliriogenic medications used during admission. Conclusion This review describes the incidence of delirium for non-critically ill older people who were prescribed at least one deliriogenic medication. Of all the deliriogenic agents reviewed, moderate quality clinical evidence supports the association between use and development of delirium except for H2RAs, which have low-quality evidence. Pharmacist-driven efforts to deprescribe deliriogenic medications in at-risk patient populations may be better focused on agents with higher-quality evidence.