Racial and Ethnic Inequalities Among Survivors of Critical Illness in the MIMIC-IV Database

Background Racial and ethnic disparities in healthcare outcomes are well-documented, but less is known about how these disparities manifest among survivors of critical illness. We examined whether Black and Hispanic ICU survivors experience different rates of 90-day and 1-year mortality and hospital readmission compared to White survivors, and whether these associations vary by age or Medicaid insurance status. Methods We conducted a retrospective cohort study using the Medical Information Mart for Intensive Care-IV (MIMIC-IV) database. Primary outcomes were 90-day and 1-year mortality; secondary outcomes included 90-day and 1-year hospital readmissions. We used Cox proportional hazards, Accelerated Failure Time (AFT), and Fine-Gray competing risk models, adjusting for age, sex, and Medicaid status. Prespecified subgroup analyses were performed among patients aged ≥60 and those admitted to surgical ICUs. Results Among 46 640 ICU survivors (mean age 63.2 years; 55.6% male; 11.8% Black; 4.6% Hispanic), Black patients had lower survival at 90 days (absolute difference (AD): −0.85% (95% CI: −1.47%, −0.23%) and 1 year (AD: −1.42% (−2.46%, −0.40%) compared to White patients. Hispanic patients had higher survival (90-day AD: 1.33% (0.39%, 2.31%); 1-year AD: 2.31% (0.67%, 4.03%). Differences were more pronounced among patients ≥60 years. Black (1-year SDHR: 1.29 (1.23, 1.34)) and Hispanic patients (SDHR: 1.22 (1.14, 1.30)) had higher readmission rates. Medicaid coverage was more common among Black (aOR: 2.26 (2.10, 2.43)) and Hispanic patients (aOR: 4.23 (3.82, 4.68)). Adjustment for Medicaid was associated with smaller survival differences between Black and White patients, with limited effect on other estimates. Conclusions In this cohort, Black ICU survivors had lower long-term survival, and both Black and Hispanic patients had higher readmission rates compared to White patients. Differences were more pronounced among older adults. Variation in Medicaid coverage may contribute to observed disparities and warrants further investigation.