Increased short-term mortality among patients presenting with altered mental status to the emergency department: A cohort study

Objectives: To evaluate the short-term mortality of adult patients presenting to the emergency department (ED) with altered mental status (AMS) as compared to other common chief complaints. Methods: Observational cohort study of adult patients (age ≥ 40) who presented to an academic ED over a 1-year period with five pre-specified complaints at ED triage: AMS, generalized weakness, chest pain, abdominal pain, and headache. Primary outcomes included 7 and 30-day mortality. Hazard ratios (HR) were calculated with 95% confidence intervals (CI) using Cox proportional hazards models adjusted for age, acuity level, and comorbidities. Results: A total of 9850 ED visits were included for analysis from which 101 (1.0%) and 295 (3.0%) died within 7 and 30 days, respectively. Among 683 AMS visits, the 7-day mortality rate was 3.2%. Mortality was lower for all other chief complaints, including generalized weakness (17/1170, 1.5%), abdominal pain (32/3609, 0.9%), chest pain (26/3548, 0.7%), and headache (4/840, 0.5%). After adjusting for key confounders, patients presenting with AMS had a significantly higher risk of death within 7 days of ED arrival than patients presenting with chest pain (HR 3.72, 95% CI 2.05 to 6.76, p < .001). Similarly, we found that patients presenting with AMS had a significantly higher risk of dying within 30 days compared to patients with chest pain (HR 3.65, 95% CI 2.49 to 5.37, p < .001), and headache (HR 2.09, 95% CI 1.09 to 4.01, p = .026). Differences were not statistically significant for comparisons with abdominal pain and generalized weakness, but confidence intervals were wide. Conclusion: Patients presenting with AMS have worse short-term prognosis than patients presenting to the ED with chest pain or headache. AMS may indicate an underlying brain dysfunction (delirium), which is associated with adverse outcomes and increased mortality.