Three-year mortality, readmission, and medical expenses in critical care survivors: A population-based cohort study

Abstract

Background: Due to the increasing number of critical care survivors, population-based studies on the long-term outcomes after discharge are necessary to inform local decision-making.

Objectives: This study aimed to investigate mortality and its risk factors, readmissions, and medical expenses of intensive care unit survivors for 3 years after hospital discharge.

Methods: This retrospective study analysed data from the National Health Insurance Service-National Sample Cohort in Korea. Of the 195,702 patients who survived and were discharged from hospital in 2012, 2693 intensive care unit patients were assigned to the case group for the study, and the remaining 193,009 were assigned to the comparison group. The primary outcome was all-cause mortality for 3 years after discharge. Secondary outcomes were all-cause hospital readmission and medical expenses in 3 years. We analysed risk factors for mortality using the Cox proportional hazard regression. The differences in hospital readmission and medical expenses between the case and comparison groups were analysed by multivariate logistic regression and independent t-tests.

Results: The 1-year, 2-year, and 3-year cumulative mortality rates in the case group were 15.9%, 20.5%, and 24.4%, respectively, and older age, disability, medical admission, and longer hospital stay increased mortality. Almost 40% of intensive care unit survivors were readmitted to hospital within 6 months of discharge, and their odds of being readmitted were significantly higher than those of the comparison group. Medical expenses were also significantly higher in the case group, with the highest paid within 6 months.

Conclusions: Mortality, hospital readmission, and medical expenses for intensive care unit survivors were the worst within 6 months of discharge. In light of the long-term recovery trajectory of critical illness, it is necessary to investigate what factors may have contributed to the negative outcome during this period. Further research is needed to determine which services primarily contributed to the increase in medical expenses.

Keywords: Critical care outcomes; Healthcare costs; Intensive care unit; Mortality; Patient readmission.