Comparison of Noninvasive, Transcutaneous Bilirubin Measurement With Conventional Total Bilirubin Testing in Near-Term and Term Newborns

Abstract

The aim of this study was to assess the performance of the BiliCheck measuring device compared with the total bilirubin measured at the laboratory analyzer (Vitros 950, Johnson & Johnson Clinical Diagnostics, Rochester, New York, USA), defined as the reference method. Transcutaneous bilirubin, using the BiliCheck, was measured in duplicate in a total of 43 near-term and term neonates at the newborn nursery. A heparinized whole-blood sample was collected almost simultaneously and sent to the laboratory for processing in duplicate using the Vitros 950. When the authors compared their results with SpectRx's (Norcross, Georgia, USA) advertising of “no bias” (posted in the company's international Web site), they show that the promise of “no bias” is untenable. Especially for bilirubin exceeding 8 mg/dL, the values obtained with the BiliCheck increasingly deviate downward. This can lead to underestimation of bilirubin when decisions are being made for or against phototherapy. The presence of this negative bias at important medical decision points may lead to the need of different cutoffs for transcutaneous and conventional bilirubin testing. Fortunately, it is well-known that the management of newborn jaundice requires phototherapy to begin at total bilirubin levels that are notably below the levels at which the kernicterus is considered an immediate threat. This safety margin makes this bias less important, and the disadvantage of using different cutoffs is counterweighted by the advantages of easy, noninvasive multiple measurements of transcutaneous bilirubin. In conclusion, the BiliCheck allows more convenient evaluation of the risk for subsequent moderate/severe hyperbilirubinemia in newborns who are candidates for early discharge from the hospital.