title: Prediction and prevention of extreme neonatal hyperbilirubinemia in a mature health maintenance organization.
abstract: OBJECTIVE
  To investigate biological and health services predictors of extreme neonatal hyperbilirubinemia in a health maintenance organization.
  
  
  METHODS
  Nested case-control study.
  
  
  METHODS
  Eleven Northern California Kaiser Permanente hospitals.
  
  
  METHODS
  The cohort consisted of 51,387 newborns born at 36 weeks or later weighing 2000 g or more. Cases were newborns with peak total serum bilirubin levels greater than or equal to 428 micromol/L (> or =25 mg/dL) (n = 73). Controls were a random sample of newborns from the cohort with peak bilirubin levels less than 428 micromol/L (<25 mg/dL) (n = 423).
  
  
  METHODS
  Review of medical records and telephone interviews.
  
  
  RESULTS
  Early jaundice was most strongly associated with case status (odds ratio [OR] = 7.3). After excluding subjects with early jaundice, the strongest predictors of hyperbilirubinemia were family history of jaundice in a newborn (OR = 6.0), exclusive breastfeeding (OR = 5.7), bruising (OR = 4.0), Asian race (OR = 3.5), cephalhematoma (OR = 3.3), maternal age of 25 years or older (OR = 3.1), and lower gestational age (OR = 0.6/week). These variables identified 61% of newborns as very low risk (about 1/4200). However, the risk in the remaining 39% was still low (1/370). More cases (79%) than controls (59%) had newborn length-of-stay and follow-up consistent with the American Academy of Pediatrics guidelines, but phototherapy use within 8 hours of the time that the guidelines recommend was uncommon in both cases (26%) and controls (33%). There were no apparent cases of kernicterus.
  
  
  CONCLUSIONS
  Prevention of extreme hyperbilirubinemia may require closer follow-up than is currently recommended by the American Academy of Pediatrics and more use of phototherapy than was observed in this study. To prevent extreme hyperbilirubinemia (> or =428 micromol/L [> or =25 mg/dL]) in 1 newborn, many newborns would need to receive these interventions.
authors.affiliation: Department of Epidemiology, UCSF Box 0560, San Francisco, CA 94143, USA. newman@itsa.ucsf.edu
authors.forename: T B
authors.initials: TB
authors.lastname: Newman
authors.forename: B
authors.initials: B
authors.lastname: Xiong
authors.forename: V M
authors.initials: VM
authors.lastname: Gonzales
authors.forename: G J
authors.initials: GJ
authors.lastname: Escobar
mesh_terms: D001663:Bilirubin / Q000097:blood; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D017408:Guidelines as Topic; D006279:Health Maintenance Organizations; D006760:Hospitalization; D006801:Humans; D007231:Infant, Newborn; D007567:Jaundice, Neonatal / Q000175:diagnosis / Q000453:epidemiology / Q000517:prevention & control* / Q000628:therapy; D007902:Length of Stay; D008297:Male; D010789:Phototherapy / Q000379:methods / Q000706:statistics & numerical data; D012189:Retrospective Studies
chemical_list: D001663:Bilirubin