Accepted for/Published in: JMIR Public Health and Surveillance
Date Submitted: Dec 7, 2025
Date Accepted: Aug 3, 2026
Socioeconomic and Regional Disparities in Long-term Mortality Among Intensive Care Unit Survivors: A Nationwide Cohort Study in South Korea
ABSTRACT
Background:
Long-term outcomes of intensive care unit (ICU) survivors remain a major public health concern. Despite the existence of a universal healthcare system in South Korea, socioeconomic disparities may affect post-critical illness survival.
Objective:
In this nationwide cohort study, we aimed to analyze the association between socioeconomic status (SES) and long-term mortality among ICU survivors.
Methods:
We conducted a retrospective population-based cohort study using data from the Korean National Health Insurance Service. We included adult patients (≥20 years) admitted to ICUs between 2015 and 2019 who survived to hospital discharge. Patients admitted for external reasons were excluded from the study. Post-discharge SES was evaluated using four indicators: insurance type (National Health Insurance [NHI] vs. Medical Aid [MA]), employment status, income level (quartiles), and residential area (metropolitan vs. non-metropolitan). The primary outcome was all-cause mortality up to eight years after discharge using the Kaplan–Meier method. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were estimated using multivariable time-dependent Cox proportional hazards models stratified by age (20–39, 40–64, and ≥65 years).
Results:
Among 871,366 adult ICU survivors, 9.6% were MA beneficiaries. Lower SES, defined as MA coverage, unemployment, lower income, and non-metropolitan residence, was consistently associated with higher long-term mortality. Compared with NHI enrollees, MA recipients had an aHR of 1.61 (95% CI, 1.58–1.63) among middle-aged adults and 1.54 (95% CI, 1.43–1.65) among younger adults. Dependent and self-employed household members had two- to three-fold higher mortality rates than did employee-insured individuals. Notably, a stepwise income–mortality gradient was evident across all age groups. Residents of non-metropolitan areas also demonstrated higher mortality (aHR 1.06–1.15). Younger individuals were particularly susceptible to SES.
Conclusions:
Despite the universal insurance system, socioeconomic disparities persist in the long term among ICU survivors. Ensuring equitable access to post-ICU care, income security, and employment stability is crucial for sustainable recovery. Clinical Trial: none
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