Long-Term Outcomes in ICU Patients with Delirium: A Population-based Cohort Study

Am J Respir Crit Care Med. 2021 Aug 15;204(4):412-420. doi: 10.1164/rccm.202002-0320OC.


Rationale: Delirium is common in the ICU and portends worse ICU and hospital outcomes. The effect of delirium in the ICU on post-hospital discharge mortality and health resource use is less well known. Objectives: To estimate mortality and health resource use 2.5 years after hospital discharge in critically ill patients admitted to the ICU. Methods: This was a population-based, propensity score-matched, retrospective cohort study of adult patients admitted to 1 of 14 medical-surgical ICUs from January 1, 2014, to June 30, 2016. Delirium was measured by using the 8-point Intensive Care Delirium Screening Checklist. The primary outcome was mortality. The secondary outcome was a composite measure of subsequent emergency department visits, hospital readmission, or mortality. Measurements and Main Results: There were 5,936 propensity score-matched patients with and without a history of incident delirium who survived to hospital discharge. Delirium was associated with increased mortality 0-30 days after hospital discharge (hazard ratio, 1.44 [95% confidence interval, 1.08-1.92]). There was no significant difference in mortality more than 30 days after hospital discharge (delirium: 3.9%, no delirium: 2.6%). There was a persistent increased risk of emergency department visits, hospital readmissions, or mortality after hospital discharge (hazard ratio, 1.12 [95% confidence interval, 1.07-1.17]) throughout the study period. Conclusions: ICU delirium is associated with increased mortality 0-30 days after hospital discharge.

Keywords: critical care; delirium; mortality.

Publication types

  • Multicenter Study
  • Observational Study

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Alberta / epidemiology
  • Critical Illness
  • Delirium / mortality*
  • Facilities and Services Utilization / statistics & numerical data*
  • Female
  • Follow-Up Studies
  • Humans
  • Intensive Care Units*
  • Male
  • Middle Aged
  • Patient Discharge
  • Prognosis
  • Propensity Score
  • Retrospective Studies
  • Survival Analysis
  • Young Adult