Comparison of transcutaneous and plasma bilirubin measurement.
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.
Leite
Maria das Graças da Cunha
Md
Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brazil. mgcleite@terra.com.br
Granato
Valéria de Araújo
Vde A
Facchini
Fernando Perazzini
FP
Marba
Sérgio Tadeu Martins
ST
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
D001663:Bilirubin