Health disparities of critically ill children according to poverty: the Korean population-based retrospective cohort study.

Background There is a lack of nationwide studies on critically ill patients' health disparity under the National Health Insurance (NHI) system. We evaluated health disparities in intensive care unit (ICU) admission, outcomes, and readmission in impoverished children. Methods We conducted a retrospective cohort study using a national database from the Korean NHI and Medical Aid Program (MAP). MAP supports the population whose household income is lower than 40% of the median Korean household income. We defined poverty as being a MAP beneficiary and compared the poverty and non-poverty groups. Patients between 28 days and 18 years old who were admitted to the ICU were included. Hospital mortality and readmission were analyzed with adjustment for patient characteristics, hospital type, and management procedures. Results Out of 17,893 patients, 1153 (6.4%) patients were in poverty. The age-standardized ICU admission rate was higher in the poverty group (126.9 vs. 80.2 per 100,000 person-years). There was more age-standardized mortality in the poverty group (11.8 vs. 4.3 per 100,000 person-years). Patients in the poverty group did not have a statistically different risk of adjusted in-hospital mortality to those in the non-poverty group (odds ratio: 1.15, confidence interval [CI]: 0.84-1.55) but had a higher readmission rate (hazard ratio 1.25, CI 1.09-1.42). Conclusion Under the NHI system, the disparity in pediatric critical care outcomes according to poverty is not definite, but the healthcare disparity in pre- and post-hospital care is a concern. Further studies are required to improve pre- and post-hospital healthcare quality of impoverished children.