Clinical Outcomes and Mortality Following Delirium: A Five-Year Follow-Up Study on Hospitalized Patients

Background: Delirium is a common neuropsychiatric syndrome among hospitalized patients and has been associated with increased short- and long-term mortality. However, data on long-term outcomes and prognostic significance remain limited, particularly in Middle Eastern populations. Methods: This prospective observational cohort study was conducted at a tertiary care hospital in Riyadh, Saudi Arabia. Adult patients admitted to medical, surgical, and intensive care units (ICUs) underwent standardized clinical neuropsychiatric assessment for delirium. Five-year follow-up data were obtained from electronic health records and phone follow-up with patients/caregivers. Clinical outcomes and survival were compared between patients with and without baseline delirium. Kaplan-Meier survival analysis assessed five-year survival, and Cox regression explored the association between delirium and time-to-death adjusting for medical/psychiatric morbidity. Results: Among 278 patients, 71 (25.5%) were diagnosed with delirium during initial hospitalization. At five years, 51 patients (18.3%) had died. Patients with delirium had higher mortality (35.2% vs. 12.6%, p < 0.001), reduced five-year survival, and greater cumulative ward and ICU stays. In Cox regression including 50 deaths with complete data, delirium at initial assessment was associated with a higher hazard of death during follow-up (HR 1.93, 95% CI 1.06-3.55). Older age per year (HR 1.02, 95% CI 1.00-1.04), kidney disease (HR 2.12, 95% CI 1.20-3.75), and psychiatric disorders (HR 2.16, 95% CI 1.17-3.97) were independently associated with a higher hazard of death. Conclusions: Delirium was associated with increased five-year mortality and adverse long-term clinical outcomes. These findings support the prognostic significance of delirium in hospitalized patients.