Antipsychotic Use in Hospitalized Adults: Rates, Indications, and Predictors

Abstract

Objectives: To investigate patterns and predictors of use of antipsychotics in hospitalized adults.

Design: Retrospective cohort study.

Setting: Academic medical center.

Participants: Individuals aged 18 and older hospitalized from August 2012 to August 2013, excluding those admitted to obstetrics and gynecology or psychiatry or with a psychotic disorder.

Measurements: Use was ascertained from pharmacy charges. Potentially excessive dosing was defined using guidelines for long-term care facilities. A review of 100 records was performed to determine reasons for use.

Results: The cohort included 17,775 admissions with a median age 64; individuals could have been admitted more than once during the study period. Antipsychotics were used in 9%, 55% of which were initiations. The most common reasons for initiation were delirium (53%) and probable delirium (12%). Potentially excessive dosing occurred in 16% of admissions exposed to an antipsychotic. Of admissions with antipsychotic initiation, 26% were discharged on these medications. Characteristics associated with initiation included age 75 and older (relative risk (RR) = 1.4, 95% confidence interval (CI) = 1.2-1.7), male sex (RR = 1.2, 95% CI = 1.1-1.4), black race (RR = 0.8, 95% CI = 0.6-0.96), delirium (RR = 4.8, 95% CI = 4.2-5.7), dementia (RR = 2.1, 95% CI = 1.7-2.6), admission to a medical service (RR = 1.2, 95% CI = 1.1-1.4), intensive care unit stay (RR = 2.1, 95% CI = 1.8-2.4), and mechanical ventilation (RR = 2.0, 95% CI = 1.7-2.4). In individuals who were initiated on an antipsychotic, characteristics associated with discharge on antipsychotics were age 75 and older (RR = 0.6, 95% CI = 0.4-0.7), discharge to any location other than home (RR = 2.5, 95% CI = 1.8-3.3), and class of in-hospital antipsychotic exposure (RR = 1.6, 95% CI = 1.1-2.3 for atypical vs typical; RR = 2.7, 95% CI = 1.9-3.8 for both vs typical).

Conclusion: Antipsychotic initiation and use were common during hospitalization, most often for delirium, and individuals were frequently discharged on these medications. Several predictors of use on discharge were identified, suggesting potential targets for decision support tools that would be used to prompt consideration of ongoing necessity.

Keywords: antipsychotics; delirium; hospitalization; medication use; pharmacoepidemiology.