Bilirubin Nomogram for Prediction of Significant Hyperbilirubinemia in North Indian Neonates.
Date
2013-04
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Objectives: (i) To construct hour-specific serum total bilirubin
(STB) nomogram in neonates born at ≥35 weeks of gestation;
(ii)To evaluate efficacy of pre-discharge bilirubin measurement in
predicting hyperbilirubinemia needing treatment.
Design: Diagnostic test performance in a prospective cohort
study.
Setting: Teaching hospital in Northern India.
Subjects: Healthy neonates with gestation ≥35 weeks or birth
weight ≥2000 g.
Intervention: Serum total bilirubin was measured in all enrolled
neonates at 24±6, 72-96 and 96-144 h of postnatal age and when
indicated clinically. Neonates were followed up during hospital
stay and after discharge till completion of 7th postnatal day.
Outcome: Key outcome was significant hyperbilirubinemia
(SHB) defined as need of phototherapy based on modified
American Academy of Pediatrics (AAP) guidelines. In neonates
born at 38 or more weeks of gestation middle line and in neonates
born at 37 or less completed weeks of gestation, lower line of
phototherapy thresholds were used to initiate phototherapy. For
construction of nomogram, STB values were clubbed in six-hour
epochs (age ± 3 hours) for postnatal age up to 48 h and twelvehour
epochs (age ± 6 hours) for age beyond 48 h. Predictive ability
of the nomogram was assessed by calculating sensitivity,
specificity, positive predictive value, negative predictive value and
likelihood ratio, by plotting receiver-operating characteristics
(ROC) curve and calculating c-statistic.
Results: 997 neonates (birth weight: 2627 ± 536 g, gestation:
37.8±1.5 weeks) were enrolled, of which 931 completed followup.
Among enrolled neonates 344 (34.5%) were low birth weight.
Rate of exclusive breastfeeding during hospital stay was more
than 80%. Bilirubin nomogram was constructed using 40th, 75th
and 95th percentile values of hour-specific bilirubin. Pre-discharge
STB of ≥95th percentile was assigned to be in high-risk zone,
between 75th and 94th centile in upper-intermediate risk zone,
between 40th and 74th centile in lower-intermediate risk zone and
below 40th percentile in low-risk zone. Among 49 neonates with
pre-discharge STB in high risk zone. 34 developed SHB (positive
predictive value: 69.4%, sensitivity: 17.1%, positive likelihood
ratio: 8.26). Among 342 neonates with pre-discharge STB in low
risk zone, 32 developed PHB (negative predictive value: 90.6%
and specificity: 42.5%, positive likelihood ratio: 0.37). Area under
curve for this risk assessment strategy was 0.73. Conclusion: Hour-specific bilirubin nomogram and STB
measurement can be used for predicting subsequent need of
phototherapy. Further studies are needed to validate performance
of risk demarcation zones defined in this hour-specific bilirubin
nomogram.
Description
Keywords
Citation
Pathak Umesh, Chawla Deepak, Kaur Saranjit, Jain Suksham. Bilirubin Nomogram for Prediction of Significant Hyperbilirubinemia in North Indian Neonates. Indian Pediatrics. 2013 April; 50(4): 383-389.