Trauma center level and postoperative mortality: a nationwide cohort study from South Korea.

Trauma center designation may influence surgical outcomes, but evidence from Asian trauma systems remains limited. This study examined the association between trauma center level and postoperative mortality following trauma surgery in South Korea. We conducted a nationwide cohort study using 2021 data from the Korean National Health Insurance Service. Adults (≥ 18 years) who underwent trauma surgery under general anesthesia at one of 17 designated trauma centers were included. Centers were categorized into Level A (highest), B, or C (lowest) based on a 2020 government evaluation. Primary outcomes were 90-day and 1-year all-cause mortality. Secondary outcomes included in-hospital postoperative complications. Multivariable logistic and Cox regression models were used, adjusting for demographic, clinical, and socioeconomic variables. Among 3,914 patients, 1,840 (47.0%) were treated at Level A centers, 1,749 (44.7%) at Level B, and 325 (8.3%) at Level C. Compared with Level A centers, the adjusted odds of 90-day mortality were higher in Level B (OR, 1.51; 95% CI, 1.20-1.91; P < 0.001) and Level C centers (OR, 4.16; 95% CI, 2.85-6.05; P < 0.001). One-year mortality was also higher in Level B (HR, 1.19; 95% CI, 1.02-1.39; P = 0.027) and Level C (HR, 1.91; 95% CI, 1.50-2.44; P < 0.001) centers. No significant differences in postoperative complication rates were observed. Lower-level trauma centers were associated with higher postoperative mortality after trauma surgery. These findings underscore the importance of trauma center designation and infrastructure in improving surgical outcomes and may inform national trauma system development.