title: Frequency of neonatal bilirubin testing and hyperbilirubinemia in a large health maintenance organization.
abstract: OBJECTIVE
  To determine the frequency and interhospital variation of bilirubin testing and identified hyperbilirubinemia in a large health maintenance organization.
  
  
  METHODS
  Retrospective cohort study.
  
  
  METHODS
  Eleven Northern California Kaiser Permanente hospitals.
  
  
  METHODS
  A total of 51,387 infants born in 1995-1996 at >/= 36 weeks' gestation and >/= 2000 g.
  
  
  METHODS
  Bilirubin tests and maximum bilirubin levels recorded in the first month after birth.
  
  
  RESULTS
  The proportion of infants receiving >/= 1 bilirubin test varied across hospitals from 17% to 52%. The frequency of bilirubin levels >/= 20 mg/dL (342 micromol/L) varied from .9% to 3.4% (mean: 2.0%), but was not associated with the frequency of bilirubin testing (R(2) = .02). Maximum bilirubin levels >/= 25 mg/dL (428 micromol/L) were identified in.15% of infants and levels >/= 30 mg/dL (513 micromol/L) in .01%.
  
  
  CONCLUSIONS
  Significant interhospital differences exist in bilirubin testing and frequency of identified hyperbilirubinemia. Bilirubin levels >/=20 mg/dL were commonly identified, but levels >/= 25 mg/dL were not.
authors.affiliation: Department of Epidemiology and Biostatistics, School of Medicine, University of California, San Francisco, California 94143, USA. newman@itsa.ucsf.edu
authors.forename: T B
authors.initials: TB
authors.lastname: Newman
authors.forename: G J
authors.initials: GJ
authors.lastname: Escobar
authors.forename: V M
authors.initials: VM
authors.lastname: Gonzales
authors.forename: M A
authors.initials: MA
authors.lastname: Armstrong
authors.forename: M N
authors.initials: MN
authors.lastname: Gardner
authors.forename: B F
authors.initials: BF
authors.lastname: Folck
mesh_terms: D002140:California / Q000453:epidemiology; D005006:Ethnicity; D005260:Female; D006279:Health Maintenance Organizations; D006801:Humans; D006932:Hyperbilirubinemia / Q000453:epidemiology* / Q000517:prevention & control*; D007231:Infant, Newborn; D008297:Male; D008403:Mass Screening / Q000706:statistics & numerical data*; D012189:Retrospective Studies