SNAPPE-II Score Performed Poorly in Predicting Neonatal Morbidity and Mortality in Very Preterm Infants

Aim: The aim of this study was to evaluate the validity of SNAPPE-II score as a predictor of neonatal morbidity (necrotizing enterocolitis (NEC), chronic lung disease (CLD) and severe intraventricular hemorrhage (IVH)) and mortality in a level 3 NICU. Methods: We included prospectively preterm infants with a gestational age of ≤32 weeks and/or birth weight of <1500g, born between June 2017 and May 2018. ROC analysis was used to identify the best cut-off point of SNAPPE-II for predicting morbidity and mortality.

Results: A total of 117 preterm infants were included in this study. Mean gestational age (±SD) was 28.1 (±2.7) weeks, with a mean birth weight (± SD) of 1180 (±405)g.

ROC curve for predicting mortality, area under the curve (AUC) was 0.85 (95%CI 0.74-0.95) which is considered good. The best cut-off SNAPPE-II score for predicting death was >41, with low positive predictive value (PPV) of 23%, high negative predictive value (NPV) of 98%, sensitivity of 77%, and specificity of 78%. On the ROC curve analysis for neonatal morbidity, the best discriminative cut-off value for SNAPPE-II for NEC was 37 (sensitivity 75%; specificity 71%; PPV 16%; NPV 97% (AUC 0.79, 95% CI= 0.66-0.92)), 31 for IVH (sensitivity 71%; specificity 62%; PPV 19%; NPV 94% (AUC 0.75, 95% CI= 0.60-0.90)), and 29 for CLD (sensitivity 71%; specificity 60%; PPV 17%; NPV 92% (AUC 0.73, 95% CI= 0.60-0.84)).

Conclusion: Our results revealed that SNAPPE-II score is a poor predictor of morbidity and mortality in very preterm infants. However, the high NPV of this score can be useful to predict infants who are at a lower risk of mortality and morbidity. A new scoring system, with better predictive values of neonatal outcome in modern tertiary NICUs is required to predict the outcomes of extremely preterm and low birth weight infants surviving today.