title: Comparison of transcutaneous and plasma bilirubin measurement.
abstract: OBJECTIVE
  To compare transcutaneous bilirubin measurements made using Bilicheck equipment with assays of capillary plasma using the Unistat bilirubinometer (Leica).
  
  
  METHODS
  Two hundred concomitant assays were performed (transcutaneous and in plasma), and the correlation and level of agreement between them was calculated. An assessment was also made of the influence of birth weight, skin color, gestational age, postnatal age and phototherapy.
  
  
  RESULTS
  The linear correlation coefficient was 0.92, and the mean difference between assays was 0.72 (+/-1.57) mg/dL, with a 95% confidence interval from -2.42 to +3.86. The best of a series of ROC curves demonstrated that transcutaneous assays at 14 mg/dL offer the best sensitivity (88.2%) and specificity (97.8%), with a positive predictive value of 78.9%, negative predictive value of 98.9 and are below the curve of 0.98.
  
  
  CONCLUSIONS
  Assays performed using Bilicheck can be substituted for capillary plasma assays up to 14 mg/dL. Above this level the device should only be used for screening for patients whose bilirubin should be assayed in blood.
authors.affiliation: Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil. mgcleite@terra.com.br
authors.forename: Maria das Graças da Cunha
authors.initials: Md
authors.lastname: Leite
authors.forename: Valéria de Araújo
authors.initials: Vde A
authors.lastname: Granato
authors.forename: Fernando Perazzini
authors.initials: FP
authors.lastname: Facchini
authors.forename: Sérgio Tadeu Martins
authors.initials: ST
authors.lastname: Marba
mesh_terms: D001663:Bilirubin / Q000097:blood*; D002196:Capillaries; D006801:Humans; D051556:Hyperbilirubinemia, Neonatal / Q000097:blood / Q000175:diagnosis*; D007231:Infant, Newborn; D015997:Neonatal Screening / Q000379:methods; D010789:Phototherapy; D011237:Predictive Value of Tests; D012372:ROC Curve; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D040521:Subcutaneous Tissue
chemical_list: D001663:Bilirubin