Thirty-day mortality among patients with acute delirium in the emergency department

The number of visits to the emergency department (ED) is growing among older patients. Older people are at risk of acute delirium, which is associated with mortality. Our primary objective was to determine the 30-day mortality outcome between older patients with and without acute delirium.

From August 2018 to October 2019, we conducted a prospective cohort study in the ED of a tertiary care and university hospital. Patients over the age of 65 years who presented to the ED were included in the study. Within the first 12 h after the ED visit, delirium was assessed by using the Thai version of the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU). We collected data on 30-day mortality, ED LOS, hospital length of stay (LOS), and the 30-day ED revisit rate.

We enrolled 173 patients in this study; 49 (28%) patients had acute delirium according to the CAM-ICU. The overall 30-day mortality was 4% (7/173). Delirium had no effect on 30-day mortality (adjusted odds ratio [OR], 2.15; 95% confidence interval [CI], 0.37-12.55; P = 0.40). Delirium was not associated with hospital LOS (adjusted mean difference -18.83 h; 95% CI, -71.94-34.28; P = 0.49) and the 30-day ED revisit rate (adjusted OR, 1.55; 95% CI, 0.59-4.11; P = 0.37). However, an increasing trend in ED LOS was observed (adjusted mean difference 16.39 h; 95% CI, -0.160-32.96; P = 0.05).

We found insufficient evidence to establish an association between delirium and 30-day mortality, hospital LOS, or 30-day emergency department revisits.

The trial was retrospectively registered in the Thai Clinical Trial Registry, identification number TCTR2021082700 on August 27, 2021.