Delirium is associated with increased mortality in the geriatric population.

Objective: The aim of this study was to investigate the prevalence of delirium and its association with mortality rates in elderly inpatients.

Methods: The medical records of 1435 patients over 65 years old who were treated at a regional university hospital and were referred to the university's Consultation and Liaison Psychiatry Clinic for psychological evaluation were retrospectively analyzed. Patients with and without a diagnosis of delirium were compared. The National Survival Database was used to determine mortality rates.

Results: The prevalence of delirium was 25.5%. The delirium group was older (p < .0001) and had a larger proportion of males (p < .0001). Mortality rate was higher in the delirium group at 1, 2, 3, 4, and 5 years (p < .0001 for all). Age, gender, lower urinary system diseases, chronic liver disease, solid hematologic malignancy, infections, and Alzheimer's disease emerged as significant parameters associated with mortality. Multivariate analysis of these parameters indicated that comorbid diseases (lower urinary system diseases, chronic liver disease, solid hematologic malignancy, infections, and Alzheimer's disease) are risk factors for mortality independent of demographic data such as age and gender.

Conclusions: Independent of all other factors, delirium is associated with higher mortality risk.