Identifying newborns at risk of significant hyperbilirubinaemia: a comparison of two recommended approaches
- 1Division of General Pediatrics, Pediatric Generalist Research Group, The Children’s Hospital of Philadelphia, PA, USA
- 2Division of Biostatistics and Epidemiology, The Children’s Hospital of Philadelphia, PA, USA
- 3Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, USA
- 4Department of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Correspondence to:
Dr R Keren
The Children’s Hospital of Philadelphia, 3535 Market Street, Room 1524, Philadelphia, PA 19104, USA; kerenemail.chop.edu
- Accepted 10 September 2004
Abstract
Aims: To compare the predictive performance of clinical risk factor assessment and pre-discharge bilirubin measurement as screening tools for identifying infants at risk of developing significant neonatal hyperbilirubinaemia (post-discharge total serum bilirubin (TSB) >95th centile).
Methods: Retrospective cohort study of term and near term infants born in an urban community teaching hospital in Pennsylvania (1993–97). A clinical risk factor scoring system was developed and its predictive performance compared to a pre-discharge TSB expressed as a risk zone on a bilirubin nomogram. Main outcome measures were prediction model discrimination, range of predicted probabilities, and sensitivity, specificity, positive and negative predictive values, and likelihood ratios for various positivity criteria.
Results: The clinical risk factor scoring system developed included birth weight, gestational age <38 weeks, oxytocin use during delivery, vacuum extraction, breast feeding, and combination breast and bottle feeding. The pre-discharge bilirubin risk zone had better discrimination (c = 0.83; 95% CI 0.80 to 0.86) than the clinical risk factor score (c = 0.71; 95% CI 0.66 to 0.76) and predicted risk of significant hyperbilirubinaemia as high as 59% compared with a maximum of 44% for the clinical risk factor score. Neither the risk score nor the pre-discharge TSB risk zone predicted the outcome with ⩾0.98 sensitivity without significantly compromising specificity (0.13 and 0.21, respectively). Multi-level clinical risk factor scores and TSB risk zones produced likelihood ratios of 0.15–3.25 and 0.05–9.43, respectively.
Conclusions: The pre-discharge bilirubin expressed as a risk zone on an hour specific bilirubin nomogram is more accurate and generates wider risk stratification than a clinical risk factor score.
- AAP, American Academy of Pediatrics
- AGA, appropriate for gestational age
- BW, birth weight
- GA, gestational age
- LGA, large for gestational age
- SGA, small for gestational age
- TSB, total serum bilirubin
Footnotes
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Funding: Dr Keren was supported by grant number K23 HD043179 from the National Institute of Child Health and Human Development, Bethesda, MD, USA
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Competing interests: none declared
