The Prediction of Mortality Risk in Preterm Infants Hospitalized in the Neonatal Intensive Care Unit Using SNAPPE-II Score System

The physiologic status of an infant at birth and at the time of admission to hospital is influential in determining the infant outcome, which can be evaluated through scoring systems. The current study aimed at predicting the mortality risk of preterm infants with a birth weight less than 1500 g hospitalized in the neonatal intensive care unit (NICU) of Vali-e-Asr Hospital, Tehran, according to SNAPPE-II (score for neonatal acute physiology with perinatal extension-II) score. The study was conducted on 343 neonates with a birth weight less than 1500 g and a gestational age less than 32 weeks hospitalized within the first 12 hours after birth. The infants’ background data was collected through a demographic characteristics questionnaire. SNAPPE-II scoring system was also completed including items such as the lowest blood pressure, the lowest arterial oxygen pressure, the lowest body temperature, the lowest serum pH, the incidence of seizure and its frequency, and urine output. Then, the final score was calculated for each infant. The cutoff point, the area under the curve, sensitivity, specificity, and positive and negative predictive values (PPV and NPV) of the system were also calculated. The correlation between neonatal variables and the outcome neonatal mortality were evaluated. Totally, 252 infants survived 24 hours after birth, and 91 passed away within this time (26.4%). The total SNAPPE-II score was 16.94 ± 16.46 in the survivor infants and 51.6 ± 22.98 in the non-survivors. The area under the receiver operating characteristic (ROC) curve with the cutoff point of 27.5 was 0.89; the sensitivity and specificity of the system were 79% and 85%, respectively. PPV and NPV of the SNAPPE-II system were 58.9% and 93.4%, respectively. A significant correlation was observed between the outcome of neonatal death and the variables of birth weight, temperature, and mean blood pressure (P = 0.00). Since the sensitivity and specificity of the SNAPPE-II system as well as its cutoff point were appropriate in the current study, and considering the simplicity of the system and the short time it takes to be completed within the first 12 hours after the birth, this system was considered a proper predictor of death in infants with neonatal mortality risk and can be routinely implemented, while providing health and medical care for Iranian infants.