Visual assessment of jaundice has long been used to gauge newborns’ risk for significant hyperbilirubinemia, but without strong evidence for the accuracy of this practice, Dr. Ron Keren of The Children’s Hospital of Philadelphia and his team note.
To investigate, the researchers had experienced nurses use the 5-point Kramer scale to rate the extent of cephalocaudal jaundice in 522 infants before discharge from the hospital. The nurses’ appraisals were paired with bilirubin measurements obtained within 8 hours of the visual assessment.
Most of the assessments were done when the infants were between 40 and 53 hours old.
Correlation between the nurses’ ratings and actual bilirubin concentration was moderate, the researchers found. Correlations were weaker for newborns less than 38 weeks gestational age (rho = 0.29) than for infants born at or beyond 38 weeks gestation (rho = 0.53).
Twenty infants developed bilirubin levels exceeding or within 1 mg/dL of the phototherapy threshold. According to the article, while the odds of significant hyperbilirubinemia increased by roughly 60% with each incremental increase in jaundice grade, “as a continuous predictor…jaundice grade had poor overall discriminatory power.”
In contrast, a complete absence of jaundice was 95% sensitive and 99% specific for ruling out a likelihood of serious bilirubin elevation, leading the research team to write that “infants with absolutely no jaundice have a very low risk of developing significant hyperbilirubinemia.”
Regarding the absence of jaundice, however, the authors caution that the negative predictive value might be lower in populations with a higher percentage of infants with hyperbilirubinemia.
Also, they note, none of the assessments in this study were done in infants less than 26 hours old. “Absence of jaundice in an infant discharged before 24 hours of age does not rule out the development of significant hyperbilirubinemia, and predischarge bilirubin screening is especially useful in that setting,” the investigators point out.
Finally, they conclude, “lack of visible jaundice prior to discharge does not obviate the need for the recommended early post-discharge follow-up by primary care pediatricians.”