Regional Variations in Mortality, Surgical Treatment, and Hospitalization in Children With Congenital Diaphragmatic Hernia: A European Population‐Based Data‐Linkage Cohort Study

Purpose: To describe mortality, surgical treatment, and hospitalization patterns in children with congenital diaphragmatic hernia (CDH) using population-based data, linked to congenital anomaly registries across Europe. Methods: This cohort study used nine EUROCAT registries in five countries (Denmark, Finland, Italy, Spain, and the United Kingdom) linked to routinely collected hospital and mortality data. Children born alive with CDH between 2005 and 2014 were included and followed until age 5 in hospital data or age 10 in death data, with the final follow-up the end of 2015. Analyses were conducted for all CDH cases and separately for isolated CDH (CDH without additional major congenital anomalies). Standardized data processing and meta-analysis methods were used to generate pooled estimates of mortality, surgical interventions, and hospital stays. Results: Among 567 children with CDH, most were isolated CDH. First year survival was 74.5% for isolated CDH, ranging from 63% to 83% between registries. Similar survival was noted for all children with CDH. Most deaths occurred within the first week. Mortality rates plateaued after infancy, with no deaths recorded after age 5. The median age at surgery was approximately 2 weeks, although this varied by region. Median hospital length of stay in infancy varied from 14 to 29 days between regions. Conclusion: In children with CDH, mortality is highest in the neonatal period, with long-term survival stabilizing after infancy. No deaths occurred after age 5 years. Regional differences in mortality and surgical timing highlight the value of population-based, harmonized data for benchmarking and international comparisons.