Disparities in Postoperative Mortality Among Working-Age Adults by Insurance Status Using South Korean National Health Insurance Service Data

This study investigated the association between insurance status and postoperative mortality using South Korean national data. The data included 540 422 patients aged 20 to 64 treated at 958 facilities. To calculate odds ratios (ORs) for in-hospital and 30-day mortality post-admission, generalized estimating equation (GEE) logistic regression was used. Significantly lower ORs for in-hospital mortality (0.55) and 30-day mortality post-admission (0.59) were found among subscribers with "employee insured" status than among those who were self-employed or Medical Aid beneficiaries. Significantly higher ORs for in-hospital mortality (1.45) and 30-day mortality post-admission (1.46) were observed among those with a <25% premium than in those with a ≥75% premium. The risk of both in-hospital and 30-day post-admission mortality consistently increased with declining socioeconomic status, confirming the presence of inequality.