Risk Stratification of Long-Term Mortality in Infants with Congenital Diaphragmatic Hernia Using the National Health Insurance Service (NHIS) Data.

Background: Congenital diaphragmatic hernia (CDH) is a rare but serious congenital anomaly linked to high mortality rates and significant long-term morbidity. Although numerous prognostic factors for short-term outcomes have been identified through hospital-based studies, data on long-term mortality at the population level are limited. Specifically, nationwide assessments of long-term outcomes for infants with CDH are scarce. This study aimed to estimate the national 5-year all-cause mortality for CDH and to create a population-level risk stratification nomogram utilizing nationwide health insurance claims data. Methods: We conducted a retrospective cohort study of infants with CDH using nationwide insurance claims data from 2002 to 2016, allowing for complete 5-year follow-up. We analyzed population-level demographic and clinical proxy variables with Cox proportional hazards models and developed a nomogram for long-term mortality risk stratification. Results: Factors such as rural residence, middle-to-high SES, respiratory distress in newborns, and CHD were associated with increased 5-year mortality in infants with CDH. The claims-based nomogram, which incorporated sociodemographic and comorbidity variables, demonstrated moderate discriminatory power (AUC 0.76; C-index 0.78) for population-level risk stratification. Conclusions: This nationwide claims-based cohort study provides population-level estimates of 5-year mortality associated with CDH and introduces a nomogram that offers moderate discriminatory ability for long-term risk stratification.