A predictive scoring system for small diaphragmatic defects in infants with congenital diaphragmatic hernia

Purpose To develop a predictive score for small diaphragmatic defects in infants with congenital diaphragmatic hernia (CDH) for determining thoracoscopic surgery indication. Methods The Japanese CDH Study Group cohort was randomly divided into derivation (n = 397) and validation (n = 396) datasets. Using logistic regression, a prediction model and weighted scoring system for small diaphragmatic defects were created from derivation dataset and validated with validation dataset. Results Six weighted variables were selected: no hydramnios, 1 point; 1 min Apgar score of 5-10, 1 point; apex type of the lung (left lung is detected radiographically in apex area), 1 point; oxygenation index < 8, 1 point; abdominal nasogastric tube (tip of the nasogastric tube is detected radiographically in the abdominal area), 2 points; no right-to-left flow of ductus arteriosus, 1 point. In validation dataset, rates of small diaphragmatic defects for Possible (0-3 points), Probable (4-5 points), and Definite (6-7 points) groups were 36%, 81%, and 94%, respectively (p < 0.001). Additionally, sensitivity, specificity, positive predictive value, and C statistics were 0.78, 0.79, 0.88, 0.76, and 0.45, 0.94, 0.94, 0.70 for Probable and Definite groups, respectively. Conclusion Our scoring system effectively predicted small diaphragmatic defects in infants with CDH.