PC3024: Transcutaneous Bilirubin Diagnostics and Newborn Racial Disparities

Background: Newborn jaundice caused by hyperbilirubinemia is one of the most common diagnoses in children worldwide. Over half of full-term newborns and 80% of pre-term newborns have symptomatic jaundice[1]. Based on current guidelines, 5-10 percent of all newborns require treatment for newborn jaundice. A much smaller fraction, about 1 in 10,000 newborns, have acute and chronic neurologic pathology related to severe hyperbilirubinemia[2].

Transcutaneous Bilirubin (TcB) measurement using commercially available point of care (POC) bilirubinometers is proven to be an effective diagnostic modality for neonatal hyperbilirubinemia.[3],[4], [5] While current technology demonstrates a high degree of correlation between measured TcB and the gold standard, total serum bilirubin (TsB) in most newborns,[6], retrospective population studies have suggested that TcB meters are less accurate for Black/African American (AA) newborns [7],[8].

Methods: We prospectively recruited two patient cohorts: 25 newborns identified by their mothers as Black/AA and 25 newborns identified as a race/ethnicity other than Black/AA. We simultaneously measured their TsBs using the clinical laboratory standard diazo reaction technique and TcBs using the Konica Minolta/Draeger JM-105. The study was performed at two sites: UCSF Levels 1 & 2 Nurseries in San Francisco, CA and the UCSF Pediatrics Clinic in Oakland, CA. Inclusion criteria included: age 1-7 days old and greater than 35 weeks gestation. Exclusion criteria included abnormal vital signs. Written consent for participation and data use/privacy was obtained from all parents of study subjects prior to enrollment.

Results: To evaluate the performance of the JM-105 as compared to the gold standard TsB laboratory test, we performed a Bland Altman analysis of agreement for both cohorts. See Figures 1 and 2. The mean difference of agreement for non-Black/AA was -0.7 mg/dL (95% limited of agreement = -4.0, 2.5). For Black/AA infants, the mean difference of agreement 0.2 mg/dL (95% limited of agreement = -3.0, 3.5).

Using multivariable regression, we demonstrated that the newborn racial identity of Black/AA predicted a 1.3 mg/dL (p < 0.006 ) of the differences between TcB and TsB.

Conclusion: Newborns identified as Black/AA were more likely to have their bilirubin overestimated using the JM-105 TcB meter as compared to non-Black/AA infants. This systematic error can result in additional blood draws, lab costs, and inpatient hospital stay. These results point to the need to improve current POC TcB technology to address this racial disparity. Innovating upon current newborn bilirubin diagnostic technology is critical from a global perspective because the highest burdens of jaundice pathology occur in geographies where many babies have darker skin tones [9]. Future research is now focused on improving in POC diagnostics such as TcB meters to optimize management of hyperbilirubinemia in newborns with diverse skin tones and racial backgrounds.