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.