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

Abstract

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.