Clinical predictive score of predischarge screening for severe hyperbilirubinemia in late preterm and term infants

Background: Early identification and appropriate follow-up of infants at risk of severe hyperbilirubinemia are part of preventing complications. This study aims to develop the clinical predictive score to predict subsequent severe hyperbilirubinemia in healthy Thai infants.

Methods: A case-control study was conducted using medical records of 147 hyperbilirubinemia cases and 147 age-matched controls among healthy late preterm and term Thai newborn infants during January 2015 and December 2016. The routinely measured TcB values at 48-54 hours of age and all predischarge clinical characteristics were collected. Multivariable logistic regression was used to find a clinical prediction model to predict subsequent severe hyperbilirubinemia within 7 days after birth which defined as a postdischarge bilirubin level exceeding the hour-specific recommended threshold for phototherapy by the American Academy of Pediatrics (AAP).

Results: The best clinical predictors for subsequent severe hyperbilirubinemia were TcB values at 48-54 hours and gestational age of infants. Predischarge TcB at 48-54 hours of life was classified into 3 levels: < 10 mg/dL, 10-12 mg/dL and > 12 mg/dL. Gestational age was categorized into 5 groups. The risk score derived from these 2 significant factors predicted subsequent severe hyperbilirubinemia with an AuROC curve of 81.0% (95% CI: 76.2-85.9%) in 3 risk group, high, moderate and low. The positive likelihood ratio for subsequent severe hyperbilirubinemia of the high-risk group (score > 5) was 4.53 (95% CI: 2.91-7.04) with specificity of 87.1%. The negative predictive value of low-risk group (score < 3) was 81%.

Conclusions: A simple predischarge prediction score using gestational age and TcB values at 48-54 hours of life was developed. This score classified late preterm and term newborn infants into 3 distinct risk levels and may be useful to identify high-risk infants for outpatient follow-up of subsequent severe hyperbilirubinemia.