Three-Month Mortality and Related Risk Factors in Delirium Patients: A Prospective Cohort Study

Abstract

Background: Delirium is a common problem in elderly patients. Recently, therapists have shifted their attention away from treatment towards prevention; therefore, investigation of related risk factors is essential in these patients. Methods: In this prospective cohort study, newly admitted elderly patients, with a Glasgow Coma Scale score above 10, were screened and enrolled. The patients were evaluated for delirium using the Neecham Confusion Scale (NCS). The risk factors included four major domains: patient characteristics (age, gender, and substance abuse), chronic diseases, acute diseases, and blood biochemical factors. Results: A total of 100 patients were assessed for delirium. The mean age of the participants was 79.9 ± 15.1 years (24% female). The proportion of in-hospital deaths was 12%, with a cumulative three-month mortality of 40%. The rate of delirium development was significantly associated with underlying factors, including cancer, hypertension, cerebrovascular accident, cirrhosis, dementia, and substance abuse. The laboratory results showed a blood urea nitrogen (BUN) level ≥ 50 mg/dL in 33% of patients with delirium. There was a significant association between BUN level and NSC score (P < 0.05). Among other laboratory variables, higher erythrocyte sedimentation rate and C-reactive protein level were significantly associated with delirium. Moreover, Kaplan-Meier survival curves for effective factors, such as drug effect, cancer, cirrhosis, dementia, and BUN, showed significant differences. Conclusions: In elderly patients, symptoms of delirium persist for three months after diagnosis. Private nursing care at home or nursing home placement, besides the assessment of delirium risk factors, is important for optimal care of elderly patients after hospitalization.