Delirium in elderly patients: Prospective prevalence across hospital services

Objectives This study aimed to determine the 1-year prevalence of delirium and the impact of hospitalization characteristics on delirium across 34 services. Methods In this prospective cohort study of elderly in-patients (>65 years, N = 10,261), delirium was determined with the Delirium Observation Screening Scale (DOS) and the Intensive Care Delirium Screening Checklist (ICDSC) in a single sample over one year. We calculated univariate and multiple logistic regression analyses to understand the power of association between delirium, 34 services, sociodemographic, and admission/discharge factors. Results The prevalence of delirium across all included services was 32%. The odds of developing delirium was highest for intensive care units (ICU, 83.3%, OR 12.34), high for intermediate care units (IMC, 39.8%, OR 1.42) and medical services (34.2%, OR 1.19), and lower for surgical services (28.7%, OR 0.72). Compared with patients without delirium, patients with delirium were older (76.6 vs. 75 years), hospitalized twice as long (14.3 vs. 7.7 days), more commonly had pre-existent dementia (OR 11.98), and were more likely to die in-hospital (OR 24.20) and be admitted from (OR 2.75–2.97) and discharged to institutions (OR 1.66–3.97). Conclusion This study elaborated on the 1-year prevalence of delirium across 34 services and confirmed previous pooled findings in addition to providing new insights regarding the course of hospitalization in elderly patients