One-year mortality and hospital readmission in survivors of COVID-19 critical illness—a population-based cohort study

Objectives — To evaluate 1-year outcomes (mortality, and recurrent hospital and ICU readmission) in adult survivors of COVID-19 critical illness compared with survivors of critical illness from non-COVID-19 pneumonia.

Design — Population-based retrospective observational cohort study.

Setting — Province of Ontario, Canada.

Patients — Six thousand ninety-eight consecutive adult patients (≥ 18 yr old) from 102 centers, admitted to ICU with COVID-19 (from January 1, 2020, to March 31, 2022), and surviving to hospital discharge.

Interventions — None.

Measurements and main results — The primary outcome was 1-year mortality. We also evaluated the number of emergency department (ED) visits, hospital readmissions, and ICU readmissions over this same time period. We compared patients using overlap propensity score-weighted, cause-specific proportional hazard models. Mean age was 59.6 years and 38.5% were female. Of these patients, 1610 (26.4%) and 375 (6.1%) were readmitted to hospital and ICU, respectively, and 917 (15.0%) died within 1 year. Compared with survivors of critical illness from non-COVID-19 pneumonia (n = 2568), those who survived COVID-19 critical illness had a lower risk of ED visit (hazard ratio [HR], 0.65 [95% CI, 0.60–0.71]), hospital readmission (HR, 0.56 [95% CI, 0.51–0.62]), ICU readmission (HR, 0.44 [95% CI, 0.37–0.53]), and mortality (HR, 0.67 [95% CI, 0.58–0.78]) within 1 year.

Conclusions — Risk of ED visit, hospital readmission, ICU readmission, and mortality within 1 year of discharge among survivors of COVID-19 critical illness was lower than survivors of critical illness from non-COVID-19 pneumonia.