title: Use of the complete blood cell count in late-onset neonatal sepsis.
abstract: BACKGROUND
  Late-onset sepsis is an important cause of morbidity and mortality in infants. Diagnosis of late-onset sepsis can be challenging. The complete blood cell count and differential have been previously evaluated as diagnostic tools for late-onset sepsis in small, single-center reports.
  
  
  OBJECTIVE
  We evaluated the diagnostic accuracy of the complete blood cell count and differential in late-onset sepsis in a large multicenter population.
  
  
  METHODS
  Using a cohort of all infants with cultures and complete blood cell count data from a large administrative database, we calculated odds ratios for infection, as well as sensitivity, specificity, positive and negative predictive values and likelihood ratios for various commonly used cut-off values.
  
  
  RESULTS
  High and low white blood cell counts, high absolute neutrophil counts, high immature-to-total neutrophil ratios and low platelet counts were associated with late-onset sepsis. Associations were weaker with increasing postnatal age at the time of the culture. Specificity was highest for white blood cell counts <1000/mm and >50,000/mm (>99%). Positive likelihood ratios were highest for white blood cell counts <1000/mm (4.1) and platelet counts <50,000/mm (3.5).
  
  
  CONCLUSIONS
  No complete blood cell count index possessed adequate sensitivity to reliably rule out late-onset sepsis in this population.
authors.affiliation: Department of Pediatrics, Duke University, Durham, NC 27715, USA.
authors.forename: Christoph P
authors.initials: CP
authors.lastname: Hornik
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Benjamin
authors.forename: Kristian C
authors.initials: KC
authors.lastname: Becker
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Benjamin
authors.forename: Jennifer
authors.initials: J
authors.lastname: Li
authors.forename: Reese H
authors.initials: RH
authors.lastname: Clark
authors.forename: Michael
authors.initials: M
authors.lastname: Cohen-Wolkowiez
authors.forename: P Brian
authors.initials: PB
authors.lastname: Smith
mesh_terms: D017668:Age of Onset; D019540:Area Under Curve; D001772:Blood Cell Count; D015331:Cohort Studies; D006801:Humans; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D016017:Odds Ratio; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D018805:Sepsis / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology