Low complication rates mask a high burden of severe morbidity: Analysis of 968 consecutive surgical procedures.

BACKGROUND: Complication incidence alone may inadequately reflect surgical quality in heterogeneous healthcare systems. This study evaluated postoperative outcomes, complication severity, and failure-to-rescue (FTR) within a mixed healthcare system using Clavien-Dindo classification and risk-adjusted analysis. METHODS: A retrospective cohort study of 968 consecutive general surgical procedures performed across three institutions between 2015 and 2025 was conducted. Procedures included elective and emergency surgery across multiple surgical specialties. Postoperative complications were classified using Clavien-Dindo criteria. Severe complications were defined as grade III-V events. Multivariable logistic regression analysis was performed to identify independent predictors of severe postoperative complications. Model discrimination, calibration, and internal validation were assessed using AUC-ROC, Hosmer-Lemeshow testing, Brier score, and bootstrap resampling. RESULTS: Overall complication incidence was 2.8%, with severe complications (Clavien-Dindo III-V) accounting for 85.2% of adverse events. Emergency surgery was associated with higher complication rates and greater complication severity. The overall FTR rate was 11.1%. In multivariable analysis, higher ASA classification (OR 3.08, 95% CI 1.70-5.61; p < 0.001), emergency surgery (OR 5.45, 95% CI 1.70-17.48; p = 0.004), operative time (OR 1.11 per 10-min increase, 95% CI 1.04-1.19; p = 0.003), and male sex (OR 7.02, 95% CI 1.57-31.39; p = 0.011) were independently associated with severe postoperative complications. Healthcare setting was not independently associated after adjustment. The model demonstrated good discrimination and calibration (AUC-ROC 0.895; optimism-corrected AUC 0.870). CONCLUSIONS: In this mixed healthcare system, low overall complication rates coexisted with a disproportionately high burden of severe postoperative morbidity. Risk-adjusted analysis suggests that patient condition, emergency surgical burden, and operative factors exert greater influence on severe complications than healthcare setting alone. Integrating complication severity and FTR analysis may provide a more meaningful assessment of surgical quality in heterogeneous healthcare environments.