Evaluation of transcutaneous bilirubinometry in preterm neonates

Transcutaneous Bilirubin Accuracy Before, During, and After Phototherapy: A Meta-Analysis

CONTEXT

Transcutaneous bilirubinometry (TcB) is used as a valid screening to identify neonates requiring measurement of total serum bilirubin (TSB) before phototherapy. Its use during and after phototherapy is not advised yet because of unknown reliability.

OBJECTIVES

To determine the agreement of TcB and TSB measurements before, during, and after phototherapy.

DATA SOURCES

PubMed Medline, Cochrane Library, and references of eligible studies were searched.

STUDY SELECTION

Prospective and retrospective cohort and cross-sectional studies reporting Bland-Altman statistics of paired TcB and TSB measurements in term and preterm newborns.

DATA EXTRACTION

Meta-analysis was performed using the Mantel-Haenszel weighted approach. The agreement between TcB and TSB in μmol/L was described by pooled mean differences (MDs) and limits of agreement (LoA).

RESULTS

Fifty-four studies were included. The pooled MD before phototherapy is 2.5 μmol/L (LoA -38.3 to 43.3). The pooled MD during phototherapy is -0.3 μmol/L (LoA -34.8 to 34.2) on covered skin and -28.6 μmol/L (LoA -105.7 to 48.5) on uncovered skin. The pooled MD after phototherapy is -34.3 μmol/L (LoA -86.7 to 18.1) on covered skin and -21.1 μmol/L (LoA -88.6 to 46.4) on uncovered skin. Subgroup analysis revealed the best agreement at the forehead. We did not find any difference in agreement between term and preterm neonates.

LIMITATIONS

Language restriction.

CONCLUSIONS

TcB measurements before and during phototherapy on covered skin show good agreement compared with TSB in term and preterm newborns. More studies are needed to evaluate the accuracy after phototherapy.

Demystifying non-invasive approaches for screening jaundice in low resource settings: a review

All national and international pediatric guidelines universally prescribe meticulous bilirubin screening for neonates as a critical measure to mitigate the incidence of acute bilirubin encephalopathy (ABE) and Kernicterus. The prevailing gold standard for jaundice detection in neonates necessitates invasive blood collection, followed by subsequent biochemical testing. While the invasive procedure provides dependable bilirubin measurements and continues to be the sole gold standard diagnostic method for assessing bilirubin concentration. There exists a pressing need to innovate non-invasive screening tools that alleviate the sampling stress endured by newborns, mitigate iatrogenic anemia, and expedite the turnaround time for obtaining results. The exploration of non-invasive modalities for bilirubin measurements is gaining momentum, driven by the overarching goal of minimizing the number of pricks inflicted upon neonates, thereby rendering screening a swift, efficient, comfortable, and dependable process. This comprehensive review article delves extensively into the array of non-invasive approaches and digital solutions that have been proposed, implemented, and utilized for neonatal bilirubin screening, with a particular emphasis on their application in low-resource settings. Within this context, the review sheds light on the existing methodologies and their practical applications, with a specific focus on transcutaneous bilirubin meters. Moreover, it underscores the prevailing open challenges in this domain and outlines potential directions for future research endeavors. Notably, the review underscores the imperative need for robust educational programs targeted at both families and healthcare personnel to expedite the process of seeking timely care for neonatal jaundice. Additionally, it underscores the necessity for the development of enhanced screening and diagnostic tools that can offer greater accuracy in clinical practice.

Transcutaneous bilirubinometry versus total serum bilirubin measurement for newborns

BACKGROUND

Jaundice is a very common condition in newborns, affecting up to 60% of term newborns and 80% of preterm newborns in the first week of life. Jaundice is caused by increased bilirubin in the blood from the breakdown of red blood cells. The gold standard for measuring bilirubin levels is obtaining a blood sample and processing it in a laboratory. However, noninvasive transcutaneous bilirubin (TcB) measurement devices are widely available and used in many settings to estimate total serum bilirubin (TSB) levels.

OBJECTIVES

To determine the diagnostic accuracy of transcutaneous bilirubin measurement for detecting hyperbilirubinaemia in newborns.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL and trial registries up to 18 August 2022. We also checked the reference lists of all included studies and relevant systematic reviews for other potentially eligible studies.

SELECTION CRITERIA

We included cross-sectional and prospective cohort studies that evaluated the accuracy of any TcB device compared to TSB measurement in term or preterm newborn infants (0 to 28 days postnatal age). All included studies provided sufficient data and information to create a 2 × 2 table for the calculation of measures of diagnostic accuracy, including sensitivities and specificities. We excluded studies that only reported correlation coefficients.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the eligibility criteria to all citations from the search and extracted data from the included studies using a standard data extraction form. We summarised the available results narratively and, where possible, we combined study data in a meta-analysis.

MAIN RESULTS

We included 23 studies, involving 5058 participants. All studies had low risk of bias as measured by the QUADAS 2 tool. The studies were conducted in different countries and settings, included newborns of different gestational and postnatal ages, compared various TcB devices (including the JM 101, JM 102, JM 103, BiliChek, Bilitest and JH20-1C) and used different cutoff values for a positive result. In most studies, the TcB measurement was taken from the forehead, sternum, or both. The sensitivity of various TcB cutoff values to detect significant hyperbilirubinaemia ranged from 74% to 100%, and specificity ranged from 18% to 89%.

AUTHORS' CONCLUSIONS

The high sensitivity of TcB to detect hyperbilirubinaemia suggests that TcB devices are reliable screening tests for ruling out hyperbilirubinaemia in newborn infants. Positive test results would require confirmation through serum bilirubin measurement.

Transcutaneous bilirubin levels in extremely preterm infants less than 30 weeks gestation

OBJECTIVE

The primary objective of this study was to determine the relationship between transcutaneous bilirubin (TcB) levels and total serum bilirubin (TSB) levels in extremely preterm infants.

STUDY DESIGN

We conducted a prospective multicenter study of extremely preterm infants less than 30 weeks gestation in California. Difference between paired TcB and TSB values were compared based on gestational age, birth weight, maternal race/ethnicity, chronological age as well as during and after phototherapy.

RESULTS

TSB values ranged from 0 to 12.6 mg/dl and the TcB values ranged from 0 to 14.2 mg/dl. TSB was predicted with a high degree of accuracy at TSB = 2.37 + 0.54 (TcB) with r = 0.786. There was good correlation across gestational age, birth weight, race/ethnic, chronological age subgroups as well as during and after phototherapy.

CONCLUSION

Our study supports the use of TcB as a screening tool for monitoring jaundice in extremely preterm infants.

Transcutaneous Bilirubin Monitoring in Preterm Infants of 23 to 34 Weeks' Gestation

OBJECTIVE

 The study aimed to evaluate the validity of transcutaneous bilirubin (TcB) measurements at three sites in premature infants born at 23^0/7 to 34^6/7 weeks' gestational age (GA) compared with total serum bilirubin (TSB) measurements.

STUDY DESIGN

 A prospective study was conducted at Banner - University Medical Center Phoenix, where informed consent was obtained from the infant's parent or legally authorized representative. Cohort A was comprised of infants 23^0/7 to 28^6/7 weeks' GA and Cohort B contained subjects 29^0/7 to 34^6/7 weeks' GA. Baseline TSB measurements were collected at approximately 24 hours of life, as the standard of care and the TcB measurements were obtained from the sternum, interscapular, and buttock areas at approximately ± 30 minutes from collection of the TSB. Statistical analysis of measurements including sensitivity, specificity, positive, and negative predictive values, and the area under the receiver operator characteristic curve (AUROC) were performed.

RESULTS

 A total of 166 infants were included in the study population. Cohort A consisted of 41 subjects and Cohort B contained 125 subjects. The results showed that baseline TcB measurements from the interscapular area were the most sensitive and specific with TSB levels >5.0 mg/dL in Cohort A. Baseline TcB measurements from the sternum demonstrated greatest sensitivity and specificity when the TSB level was >8.0 mg/dL in Cohort B. In general, each of the three sites in both cohorts demonstrated excellent AUROCs and negative predictive values.

CONCLUSION

 The use of a TcB meter in preterm infants can be a reliable noninvasive screening tool for hyperbilirubinemia, and it may be beneficial in decreasing painful stimuli and iatrogenic blood loss when used as an adjunct to TSB monitoring.

KEY POINTS

· Interscapular TcB is sensitive/specific in 23 to 29 weeks' GA.. · Sternal TcB is sensitive/specific in 29 to 35 weeks' GA.. · TcB readings are reliable in preterm infants.. · TcB is reliable when serum bilirubin is >5.0 mg/dL..

Reliability of transcutaneous bilirubin determination based on skin color determined by a neonatal skin color scale of our own

Measurement of transcutaneous bilirubin (TcB) is widely used to estimate serum bilirubin (SB). However, its reliability depending on skin tone is still controversial. Ethnic classification does not correlate well with skin tone. We aimed to determine the reliability of transcutaneous bilirubin in a multiethnic population based on skin color according to our neonatal skin color scale. We conducted a prospective, observational study comparing SB and TcB among different skin colors. With the blood sample routinely obtained at 48-72 h for the screening of inborn errors of metabolism, we determined SB and TcB with a jaundice meter. We obtained data from 1359 newborns (color 1 337, color 2 750, color 3 249, color 4 23) and analyzed 1549 dyads SB/TcB. Correlation between TcB and serum bilirubin was very good (R² = 0.908-0.956), globally and by color group, with slight differences between darker and lighter skin colors. Bland-Altman plots showed different mean bias depending on skin color. Conclusions: Our study not only supports the reliability of TcB to assess SB regardless of skin color, but also supports the fact that TcB tends to overestimate SB in a higher degree in dark-skinned neonates. This may help reduce the number of blood samples for newborns. What is Known: • Jaundice meters are extensively used to diagnose neonatal hyperbilirubinemia, although controversies exist on their reliability depending on skin color. • Only a few studies have analyzed their accuracy in multiethnic populations, but none has used a validated neonatal skin color scale. What is New: • We verified correlation between serum and transcutaneous bilirubin in a multiethnic population depending on skin color after classifying our neonates into color groups with our own validated neonatal skin color scale.

Noninvasive methods for bilirubin measurements in newborns: A report

New technologies have become available for noninvasive assessments of neonatal hyperbilirubinemia. Our objective is to review the noninvasive methods for measuring bilirubin in the newborn. We searched relevant literature from 1966 to January 1, 2020, which included cross-sectional studies to define the accuracy of any noninvasive methods for measuring or estimating total serum/plasma bilirubin (TB) levels in newborns. We identified and included 83 relevant studies of direct visual assessment, icterometry, mobile phone applications, and transcutaneous bilirubinometry (TcB). Compared with laboratory TB measurements, visual assessment was the least accurate and least reliable (r: 0.37 to 074), while TcB was the most accurate, but not always near-equivalent (r: 0.45 to 0.99). The sensitivity and specificity of TcB cut-off values to detect significant hyperbilirubinemia (TB>95th percentile for age in hours) ranged from 74% to 100% and 18% to 89%, respectively.

Drive-through transcutaneous bilirubin screening for neonatal jaundice: A safe and efficient system during the COVID-19 pandemic

The coronavirus disease 2019 (COVID-19) cases was on an increasing trend, including in Malaysia. The Malaysian Ministry of Health had implemented a range of measures, such as the use of masks and social distancing, to reduce the risk of transmission. Traditionally, newborns are evaluated for neonatal jaundice using visual assessment, a capillary heel prick and serum bilirubin (SB) sampling in primary health-care clinics. This approach requires the physical presence of both parents and their newborns in the primary health-care clinics, causing crowding and increasing the risk of COVID-19 infections. To alleviate crowding, we implemented the transcutaneous bilirubin drive-through (DT) service, which is an established, non-invasive, painless and rapid method to determine the bilirubin levels. Throughout the screening, both parents and baby will be confined to their car. A total of 1842 babies were screened in our DT setting from April to July 2020. Of the total babies, 298 (16.1%) required venesection for SB measurement and 85 required admission for phototherapy. None with severe jaundice were missed since the implementation of this service. The average test duration per neonate was less than 5 min, while conventional venous bilirubin laboratory testing required an average of 1.5 h per neonate. The cost of the SB laboratory test and consumables was approximately USD 5 per test, with an estimated cost savings of USD 7720. DT screening may be introduced in health-care settings to reduce crowding and eliminate the need of painful blood sampling in newborns.

The forehead is a better site than the sternum to check transcutaneous bilirubin during phototherapy in sick infants

Background

To confirm the accuracy of transcutaneous bilirubin (TcB) in the neonatal intensive care unit both with and without phototherapy, and compare forehead and sternum as the TcB assessment site.

Methods

We simultaneously assessed the total serum bilirubin (TSB) and TcB at the forehead and sternum, using a JM-103 bilirubinometer. We analyzed the correlation between the TSB and TcB assessed at the forehead and sternum, with measurements classified as ‘without phototherapy’ (before phototherapy and > 24 hours after phototherapy discontinuation) and ‘with phototherapy’ (after 24 hours of phototherapy).

Results

There were 1,084 paired forehead and sternum TcB measurements, with the corresponding TSB measurement, from 384 infants. Their mean gestational age of 35.4 ± 3.2 weeks (62% were preterm) and a mean birth weight of 2434 ± 768 grams, and TSB was 6.61 ± 3.56 mg/dL. Without phototherapy, TcB values at the forehead and sternum were correlated well to the TSB value (r = 0.925 and 0.915, respectively). With phototherapy, TcB values at the forehead and sternum were significantly correlated with the TSB value, but TcB at the forehead (r = 0.751) was a better match to the TSB than was TcB at the sternum (r = 0.668). Additionally, Bland-Altman plots showed a greater degree of underestimation of the TSB by TcB at the sternum with phototherapy.

Conclusions

TcB was more accurate in infants not receiving phototherapy. During phototherapy, it is better to assess TcB at the forehead rather than at the sternum.

Rate of rise of total serum bilirubin in very low birth weight preterm infants

BACKGROUND

To assess the postnatal rate of rise (ROR) of total serum bilirubin (TSB) in very low birth weight (VLBW) preterm infants, to determine risk factors associated with a rapid rise (>90th percentile), and to compare ROR and hour-specific TSB at postnatal 12-48 h with data of term infants retrieved from the literature.

METHODS

Retrospective analysis of 2430 routine TSB concentrations obtained between birth and initiation of phototherapy in 483 VLBW infants.

RESULTS

TSB increased by a median (interquartile range) ROR of 0.15 (0.11-0.19) mg/dL/h. The 50th percentile of TSB was below the 40th percentile of (near-)term counterparts at 12-48 h. TSB ROR correlated with the age at initiation (R_S = -0.687; p < 0.001) and the duration (R_S = 0.444; p < 0.001) of phototherapy. ROR >90th percentile (>0.25 mg/dL/h) was associated with lower gestational ages [27.2 (25.4-29.3) vs. 28.4 (26.4-30.4) weeks], lower birth weights [978 (665-1120) vs. 1045 (814-1300) g], and lower 5-min Apgar scores [7 (7-8) vs. 8 (7-9)].

CONCLUSION

ROR of TSB is an indicator for early and prolonged phototherapy. While hour-specific TSB and ROR at 12-48 h are lower than those reported for (near-)term infants, TSB appears to rise more rapidly in infants with low gestational age, low birth weight, and low 5-min Apgar score.

The accuracy of transcutaneous bilirubinometry in preterm infants

OBJECTIVE

To evaluate the correlation between total serum and transcutaneous bilirubin and to determine the reliability of transcutaneous bilirubinometry for screening and monitoring of neonatal jaundice among preterms.

STUDY DESIGN

Ninety nine infants with gestational ages ≤34 weeks were prospectively enrolled. Babies were classified into three groups as; 24-28, 29-31, and 32-34 weeks. Total serum bilirubin and simultaneous transcutaneous bilirubin were measured before the onset of phototheraphy, during and at 24 h after discontinuing phototherapy.

RESULTS

Total serum bilirubin significantly correlated with transcutaneous bilirubin in the whole cohort (r = 0.867, p < 0.001) and in each group before, during and after phototheraphy. Hypotension was the only variable which effects the difference between two methods at postnatal first day of life (p = 0.039).

CONCLUSION

Transcutaneous bilirubin levels were highly correlated with total serum bilirubin levels even in 24-28 GW babies. Transcutaneous bilirubin may be useful for screening and monitoring of jaundice in very preterm newborns.

Comparison of Diagnostic Accuracy of Different Sites for Transcutaneous Bilirubin Measurement in Early Preterm Infants

OBJECTIVE

To evaluate correlation of transcutaneous bilirubin (TcB) measured at different body sites with serum total bilirubin (TSB) in early preterm infants.

METHODS

This hospital based prospective comparative study was carried out in the Department of Pediatrics, SMS Medical College, Jaipur between April 2015 to March 2016. Early preterm infants with gestational age ≤ 34 weeks in whom clinical jaundice was significant mandating TSB measurement were included in the study. Study subjects who met the inclusion criteria were chosen consecutively. Neonates in whom phototherapy was already initiated and those with poor perfusion (capillary refill time > 3 s) were excluded from the study. All the measurements were carried out within first postnatal week. Transcutaneous bilirubin was measured from three sites: forehead, sternum and interscapular region and within 15 min of TcB measurement, blood samples were taken and serum bilirubin level was calculated.

RESULTS

Correlation coefficients of transcutaneous bilirubin measured from forehead, sternum and interscapular sites were 0.82, 0.84 and 0.86 respectively. TcB measured from all the three sites correlated significantly with serum bilirubin (p < 0.001), but the correlation was best at interscapular site. Sensitivity, specificity and false negative rates were calculated with respect to starting phototherapy. Interscapular site had the highest sensitivity and lowest false negative rate (87.6 and 12.4% respectively) as compared to forehead (79.2 and 20.8% respectively) and sternum (87.1 and 12.9% respectively).

CONCLUSIONS

Transcutaneous bilirubin measurement is an acceptable method for identification of hyperbilirubinemia requiring treatment in early preterm newborns. The authors recommend interscapular region as a reliable site in infants of gestational age ≤34 wk for measuring transcutaneous bilirubin.

A Novel Non-invasive Technique of Measuring Bilirubin Levels Using BiliCapture

OBJECTIVES

In preterm infants, hyperbilirubinemia is common and can impair the central nervous system. The tests available for measuring bilirubin is to collect blood from heel pricking and occasionally taking blood samples from inserted cannulas, which is painful. Therefore, there is a need to develop a non-invasive device to detect bilirubin levels in newborns and interpret the severity of jaundice.

METHODS

We conducted a cross-sectional study of 100 neonates. Patient data was collected between June 2015 and December 2016 from King Khalid Hospital at Al-Majma'ah, Saudi Arabia, and Alpine Hospital, Gurgaon, India. The mean gestational age of neonates was 39.0 weeks. Total bilirubin was measured using a transcutaneous bilirubinometer on the forehead and obtaining optical imaging through scanning of conjunctiva of eyes, also referred to as BiliChek and BiliCapture, respectively. Later the blood samples were obtained from these patients and tested in the laboratory to determine total serum bilirubin (TSB) levels.

RESULTS

The concentration of bilirubin as measured from serum, BiliChek, and BiliCapture were 10.7±2.0, 11.6±2.7, and 13.1±2.3 mg/dL, respectively. Correlation was high between TSB and BiliChek (r2 = 0.88) and between TSB and BiliCapture (r2 = 0.73). The Bland-Altman plots showed good agreement when comparing bilirubin values for both BiliChek and BiliCapture devices. Bilirubin measurement was further checked for the sensitivity and specificity and was 88.0% and 76.0% using BiliChek and 92.0% and 75.6% using BiliCapture, respectively.

CONCLUSIONS

The optical imaging of conjunctiva for bilirubin assay is a safe alternative to a laboratory bilirubin assay and transcutaneous bilirubinometer BiliChek.

Transcutaneous bilirubinometer use and practices surrounding jaundice in 150 California newborn intensive care units

OBJECTIVES

Transcutaneous bilirubin measurements (TcBs) provide a noninvasive method for screening infants for hyperbilirubinemia and have been used extensively in term and late preterm newborns in well baby nurseries, offices, and outpatient clinics. Several studies have also demonstrated the utility of TcBs as a screening tool for infants > 28 weeks' gestation and their ability to reduce the need for blood sampling. The objectives of this study are to identify how often TcBs are used among California Newborn Intensive Care Units (NICUs) in preterm, late preterm and term infants, and other aspects of jaundice management.

METHODS

We conducted a survey on TcB use and practices relating to jaundice management in 150 California NICUs between April and October 2016.

RESULTS

TcB screening is routinely used in 28% (42/150) of NICUs. Only 7% (11/150) of NICUs use TcB in preterm infants < 28 weeks. Practice varied similarly across NICU levels of care. Among the subset of NICUs that responded to questions related to phototherapy and screening practices, prophylactic phototherapy was used in 38% (23/59) and 90% (55/61) screened for glucose-6-phosphate dehydrogenase deficiency based on race, ethnicity, and/or family history.

CONCLUSION(S)

Despite studies validating the accuracy of TcB in preterm infants > 28 weeks, only 28% of California NICUs routinely use TcB devices. TcB screening in infants < 28 weeks gestation is not widely used and no recommendation can be made in this regard until there is more experience with its application using a standardized protocol in these infants and on a large scale.

Agreement test of transcutaneous bilirubin and bilistick with serum bilirubin in preterm infants receiving phototherapy

Background

This study compares the minimally invasive Bilistick and a noninvasive method with standard Total Serum Bilirubin (TSB) measurement in preterm newborns receiving phototherapy. We assess the agreement of Transcutaneous Bilirubinometer (TcB) and Bilistick bilirubin measurements with standard TSB measurement in preterm infants receiving phototherapy.

Methods

Bilirubin was measured by using TcB and Bilistick in 94 preterm infants in RSCM Jakarta Neonatal Ward from October 2016 to March 2017, with gestational ages of < 35 weeks, before phototherapy and after 24 and 48 h of phototherapy.

Results

There was significant correlation before, at 24 and 48 h of phototherapy between TSB and either TcB (r = 0.874; r = 0.889; r = 0.878 respectively; p < 0.0001), or Bilistick (r = 0.868; r = 0.877; r = 0.918 respectively; p < 0.0001). The mean difference and limits of agreement before, at 24 and 48 h of phototherapy between TcB and TSB were 0.81 ± 1.51 mg/dL (− 2.14 to 3.77 mg/dL); 0.43 ± 1.57 mg/dL (− 2.66 to 3.51 mg/dL); 0.41 ± 1.58 mg/dL (− 2.69 to 3.50 mg/dL), respectively. For Bilistick they were − 1.50 ± 1.47 mg/dL (− 4.38 to 1.38 mg/dL); − 1.43 ± 1.47 mg/dL (− 4.32 to 1.46 mg/dL); − 1,15 ± 1.31 mg/dL (− 3,72 to 1,42 mg/dL), respectively.

Conclusions

Both methods are reliable for measuring TSB before, during, and after phototherapy in preterm infants. TcB tends to overestimate while Bilistick underestimates TSB.

Comparison of Transcutaneous and Serum Bilirubin Measurements in Neonates 30 to 34 Weeks' Gestation Before, During, and After Phototherapy

BACKGROUND

The use of noninvasive, transcutaneous bilirubin monitoring (TcB) as a jaundice screen in full-term infants is well established; however, there is a paucity of research evaluating the use of TcB in premature infants.

PURPOSE

To compare agreement and consistency of transcutaneous and serum bilirubin measurements in a multiracial premature infant population ranging from 30 to 34(Equation is included in full-text article.)weeks' gestation before, during, and after phototherapy.

METHODS

Forty-five neonates, 30 to 34(Equation is included in full-text article.)weeks' gestation, were enrolled in this prospective, correlational study over a 12-month period. One set of paired transcutaneous and serum bilirubin measurements, per neonate, was obtained before phototherapy, during therapy, and after phototherapy. Exclusion criteria included neonates with positive direct coombs test or evidence of hemolytic disease, major congenital anomalies, hydrops fetalis, and those not expected to survive.

RESULTS

There was a strong, positive correlation between TcB and total serum monitoring (TSB) measurements obtained pretherapy (r = 0.797, P < .001). A moderate correlation was noted between TcB and TSB measurements obtained during therapy (r = 0.588, P < .001). A strong correlation was noted between TcB and TSB measurements obtained posttherapy (r = 0.869, P < .001). There were no significant differences between paired samples across time (F = 0.891, P = .41, partial η = 0.01). The TSB measurements were consistently lower than TcB pretherapy, during, and posttherapy.

IMPLICATIONS FOR PRACTICE

The TcB measurements provide a reliable estimation, generally within 2 to 3 mg/dL of TSB levels, in premature infants 30 to 34(Equation is included in full-text article.)weeks' gestation.

IMPLICATIONS FOR RESEARCH

Investigation of consumption of time and nursing personnel required to perform TcB testing, compared with TSB testing, is indicated. Cost analyses comparing TcB-driven screening protocols and interval TSB measurements, among premature infants, are indicated. As newer generations of TcB devices are approved for use, additional studies using mixed-race populations of premature infants will be necessary to continue to evaluate the reliability and validity of this screening tool within the everyday neonatal intensive care unit.

Early predictive value of cord blood bilirubin and dynamic monitoring of transcutaneous bilirubin for hyperbilirubinemia of newborns

Objective

To study the early predictive value of cord blood bilirubin and dynamic monitoring of transcutaneous bilirubin for hyperbilirubinemia of newborns.

Methods

389 newborns delivered from June 2014 to December 2015 were enrolled as the research subjects; detailed records were made about the general data of newborns and mothers, and after cord blood bilirubin being graded, the incidence of hyperbilirubinemia was counted, and the prediction efficiency of cord blood bilirubin was analyzed by receiver operator characteristic (ROC) curve. At the same time, the transcutaneous bilirubin was detected continuously when the neonate was born and 24 h, 48 h and 72 h after birth, and the relativity between transcutaneous bilirubin at 72 h and serum bilirubin was analyzed.

Results

No significant difference was found in the hyperbilirubinemia group and the non-hyperbilirubinemia group concerning general data of the newborns and their mothers. With the concentration of cord blood bilirubin increased, the incidence of hyperbilirubinemia also increased; separate prediction of hyperbilirubinemia by cord blood bilirubin showed a sensitivity and specificity of 71.4% and 65.6% respectively, and they need further dynamic monitoring. The daily mean of transcutaneous bilirubin in hyperbilirubinemia group was significantly higher than that in non-hyperbilirubinemia group at 24 h, 48 h and 72 h, and the measurement value of transcutaneous bilirubin at 72 h had a high correlation with serum bilirubin. When transcutaneous bilirubin value is higher than 18, the incidence of hyperbilirubinemia should be considered.

Conclusions

The increase of cord blood bilirubin effectively predict the occurrence of neonatal hyperbilirubinemia. There is a good correlation between levels of transcutaneous bilirubin and serum bilirubin. Moreover, combined detection of transcutaneous bilirubin and cord blood bilirubin can significantly improve the prediction accuracy of hyperbilirubinemia.

Patched Skin Bilirubin Assay to Monitor Neonates Born Extremely Preterm Undergoing Phototherapy

OBJECTIVE

To verify the reliability and safety of transcutaneous bilirubin (TcB) measurements in patched skin areas in neonates born extremely preterm under phototherapy.

STUDY DESIGN

Sixty neonates (<30 weeks' gestation) receiving phototherapy were enrolled and TcB was measured via a second-generation transcutaneous bilirubinometer in patched skin areas (of at least 2.5 cm diameter). Total serum bilirubin (TSB), lactate, pH, hemoglobin, and skin temperature were measured within 10 minutes of the TcB assay. Clinicians were blinded to TcB values, and clinical decisions about phototherapy were made with the TSB measurement only.

RESULTS

TcB and TSB significantly were correlated (r = 0.84; P <.001), even after adjustment for hemoglobin, pH, lactate, gestational and postnatal age (standardized β = 0.8; P <.001; adjusted R² = 0.75), or treatment duration (standardized β = 0.8; P <.001; adjusted R² = 0.7). When the Bland-Altman analysis was used, TcB overestimated TSB at high values (mean difference TSB - TcB: -2.8 [2.4] mg/dL). If clinicians used the TcB only, no neonate would have had phototherapy stopped prematurely, and 21 (35%) would have continued phototherapy when it could have been stopped.

CONCLUSIONS

The correlation between TSB and TcB (measured in patched skin areas) was comparable with that obtained in more mature neonates, and it was not influenced by clinical variables or factors affecting skin bilirubin passage. TcB overestimated TSB, and this may expose infants born preterm to unnecessary phototherapy, although it could spare approximately 65% of TSB assays.

Defining the limitations of transcutaneous bilirubin measurement in late preterm newborns

OBJECTIVE

The objective of this study is to determine the impact of postnatal age on the bias between transcutaneous (TcB) and total serum bilirubin (TSB), and evaluate a TcB screening protocol.

STUDY DESIGN

Preterm and term infants had paired TcB and TSB performed on days 1 to 3 of life; a subset of preterm infants had measurements on days 4 to 7. Sensitivity and specificity of TcB (plotted on an age-specific TSB nomogram) for prediction of high-intermediate (HIR) or high-risk TSB were calculated.

RESULTS

Median TcB bias was 2.6 and 2.5 mg dl^-1 for term and preterm infants in the first 3 days of life, respectively. However, median bias was 2.2 mg dl^-1 for preterm infants at 4 to 7 days of life. TcB in preterm infants predicted HIR or high-risk TSB with 94% sensitivity and 56% specificity.

CONCLUSION

TcB screening protocols developed for term infants can be used for late preterm infants in the first 3 days of life.

Diagnosis Accuracy of Transcutaneous Bilirubinometry in Very Preterm Newborns

BACKGROUND

Transcutaneous bilirubin (TcB) is a validated test for systematic screening of neonatal hyperbilirubinemia and monitoring term and near-term infants under phototherapy.

OBJECTIVES

To evaluate TcB diagnostic accuracy for very preterm neonates.

METHODS

Total serum bilirubin (TSB) and TcB measurements were performed prospectively in a multicenter sample of newborns <30 weeks of gestational age (GA). TcB sensitivity, specificity, predictive values, and likelihood ratios for the detection of neonates requiring phototherapy were calculated over the first 15 days of life, with or without phototherapy, with the expectation of achieving a detection rate of hyperbilirubinemia of over 95%. The potential influence of neonatal characteristics on the discordance between TcB and TSB in very preterm newborns was analyzed using multivariate multilevel logistic regression analyses.

RESULTS

Altogether, 481 measurements were analyzed in 167 preterm patients. Mean GA was 27.6 ± 1.6 weeks. The rates of newborns requiring phototherapy were 52% in the first 3 days, 16% from the 4th to the 7th day, and 2% during the second week. Diagnostic performance was similar among babies with or without phototherapy. TcB sensitivity decreased over time from 100% (93.9-100.0) to 50% (1.3-98.7). Specificity showed an inverse evolution from 14.8% (7.0-26.2) to 80.7% (72.2-89.2). The best performance was that of negative predictive values which varied from 95.5 to 100.0. False negatives were rare throughout the study (0.8% of measurements). In a multivariate analysis, the only factor significantly influencing discordance between TcB and TSB was postnatal age. We did not find any impact of GA and skin color.

CONCLUSION

Among very preterm babies, TcB measurements might be useful for screening for neonatal jaundice in the first 2 weeks of life. In case of a TcB value below the phototherapy threshold, invasive TSB quantification could be unnecessary, with potential avoidance of blood drawing.

Clinical utility of transcutaneous bilirubinometer (TcB) in very low birth weight (VLBW) infants

OBJECTIVE

This is a comprehensive study designed to evaluate the clinical usefulness of transcutaneous bilirubinometry (TcB) in very low birth weight (VLBW) newborns of African American (AA) descent.

METHODS

TcB was conducted at the anterior superior iliac spine (ASIS), temporal region and sternum within 2 h of total serum bilirubin (TSB) measurements in newborns born at ≤32 weeks' gestation prospectively. Average (AVG) TcB levels were also calculated. The relationships between TSB and TcB levels were analyzed using non-parametric Spearman bivariate correlations, a Bland-Altman plot procedure and a decision tree (DT) analysis.

RESULTS

One hundred newborns and 555 TSB data points were available. Eighty-nine percent of the newborns were AA. A significant correlation (P<0.0001) was observed between TSB and TcB values obtained at the ASIS (r=0.73), sternum (0.73), temporal region (0.61) and AVG (0.77). The Bland-Altman plot revealed a good agreement between AVG TcB values and TSB values. A DT analysis indicated that AVG TcB was also found to be the most significant predictor of TSB values in both the no phototherapy (PT) and biliblanket subgroups.

CONCLUSION

TcB can be used reliably in VLBW AA newborns in the absence of overhead PT. The use of TcB in monitoring jaundice in VLBW newborns would help decrease the number of blood draws and cost of care.

Screening for Hyperbilirubinemia in Japanese Very Low Birthweight Infants Using Transcutaneous Bilirubinometry

OBJECTIVES

To assess the accuracy of transcutaneous bilirubin (TcB) measurements at 5 different body sites in Japanese very low birthweight (VLBW) infants and to determine a cut-off value of TcB to detect total serum/plasma bilirubin (TB) levels ≥10 mg/dL (171 μM).

STUDY DESIGN

In a prospective multicenter study, 85 Japanese VLBW infants were enrolled from 5 neonatal intensive care units during the study period. A total of 383 blood samples from infants not receiving phototherapy or ≥24 hours postphototherapy were analyzed. TcB was measured at the forehead, sternum, upper back, lower abdomen, and waist within 1 hour of blood collection. Linear regression analysis and Bland-Altman plots were used to compare TcB values at each site with TB levels. The TcB cut-off value for detecting TB ≥10 mg/dL was determined by receiver operating characteristics curve analysis.

RESULTS

TcB significantly correlated with TB, but the coefficient of determination varied among the sites (forehead: 0.5294, sternum: 0.6488, upper back: 0.6321, lower abdomen: 0.5430, waist: 0.7396). At a TcB value ≥8, the sensitivity was 100% at the sternum and upper back, 85% at the waist, 84% at the forehead, and 64% at the lower abdomen to detect TB ≥10 mg/dL.

CONCLUSIONS

In Japanese VLBW infants, the accuracy of TcB measurements varies according to body site. TcB ≥8 on the sternum or upper back is more reliable than that on the forehead, lower abdomen, or waist to detect TB levels ≥10 mg/dL.

Screening neonatal jaundice based on the sclera color of the eye using digital photography

A new screening technique for neonatal jaundice is proposed exploiting the yellow discoloration in the sclera. It involves taking digital photographs of newborn infants' eyes (n = 110) and processing the pixel colour values of the sclera to predict the total serum bilirubin (TSB) levels. This technique has linear and rank correlation coefficients of 0.75 and 0.72 (both p<0.01) with the measured TSB. The mean difference ( ± SD) is 0.00 ± 41.60 µmol/l. The receiver operating characteristic curve shows that this technique can identify subjects with TSB above 205 µmol/l with sensitivity of 1.00 and specificity of 0.50, showing its potential as a screening device.

Transcutaneous bilirubin levels in newborns <35 weeks' gestation

OBJECTIVE

In infants <35 weeks' gestation, we sought to define the transcutaneous bilirubin (TcB) levels at which a total serum bilirubin (TSB) level suggesting the need for phototherapy is unlikely to occur and a TSB measurement can, therefore, be avoided.

STUDY DESIGN

Nursing staff performed 896 TcB measurements within 1 h of a TSB on 225 neonates 26 0/7-34 6/7 weeks' postmenstrual age (PMA). Generalized linear models were fit with generalized estimating equations (GEEs) to model the probability of having a TSB level at or above the phototherapy initiation cutpoint as a function of the TcB; these methods allow for multiple tests per infant.

RESULTS

The mean difference between TcB and TSB measurements was <1 mg dl(-1) for each PMA category. When the TcB was at least 3 mg dl(-1) below the TSB cutpoint for phototherapy, there was a ⩾98% probability that the TSB was not at, or above, the recommended phototherapy level. The single exception to this was a phototherapy level of 6 mg dl(-1) for infants of 28 0/7-29 6/7 weeks' PMA, where a TcB of 4 mg dl(-1) below the phototherapy level (ie a TcB ⩽2 mg dl(-1)) was necessary to achieve ⩾98% probability.

CONCLUSION

Our data support the use of routine TcB screening for infants 28-34 6/7 weeks' gestation. TcB screening in the neonatal intensive care unit can identify infants who require a TSB to confirm or exclude the need for phototherapy.

Transcutaneous bilirubinometry

Although the modern era of transcutaneous bilirubin monitoring (TcB) began only about 35 years ago, this screening tool is now widely used in newborn nurseries and outpatient clinics, offices, and emergency departments to obtain a rapid and non-invasive estimate of the degree of hyperbilirubinemia. TcB devices have become more sophisticated, and major breakthroughs include the following: (a) ability to report a bilirubin value rather than an index value, (b) enhanced correction for chromophores other than bilirubin, and (c) technologic improvements including interface with electronic medical records. Good agreement with laboratory bilirubin measurement has been demonstrated, and the ability of TcB screening to predict and decrease the incidence of subsequent hyperbilirubinemia has been well-documented. To date, it has not been shown that this screening results in improved long-term outcomes.

Influence of skin colour on diagnostic accuracy of the jaundice meter JM 103 in newborns

AIM

To assess the diagnostic accuracy of the JM 103 as a screening tool for neonatal jaundice and explore differential effects based on skin colour.

METHODS

We prospectively compared the transcutaneous bilirubin (TcB) and serum bilirubin (TSB) measurements of newborns over a 3 month-period. Skin colour was assigned via reference colour swatches. Diagnostic measures of the TcB/TSB comparison were made and clinically relevant TcB cut-off values were determined for each skin colour group.

RESULTS

451 infants (51 light, 326 medium and 74 dark skin colour) were recruited. The association between TcB and TSB was high for all skin colours (rs>0.9). The Bland-Altman analysis showed an absolute mean difference between the two measures of 13.3±26.4 µmol/L with broad limits of agreement (-39.4-66.0 µmol/L), with TcB underestimating TSB in light and medium skin colours and overestimating in dark skin colour. Diagnostic measures were also consistently high across skin colours, with no clinically significant differences observed.

CONCLUSIONS

The JM 103 is a useful screening tool to identify infants in need of serum bilirubin, regardless of skin colour. The effect of skin colour on the accuracy of this device at high levels of serum bilirubin could not be assessed fully due to small numbers in the light and dark groups.

Transcutaneous bilirubinometry is not influenced by term or skin color in neonates

BACKGROUND

The utility of transcutaneous bilirubin measurements (TcB) in screening for hyperbilirubinemia in preterm infants (<34 weeks) and in non-white infants remains a matter of debate.

AIM

To evaluate accuracy of TcB in preterm and term infants of different ethnic backgrounds, using a second generation bilirubinometer.

STUDY DESIGN

The Draeger JM-103® device was used to measure TcB. Eighty five measurements of TcB and total serum bilirubin (TSB) were retrospectively compared. Neonates were stratified into groups according to gestational age: <34 weeks (group 1, n=44) and >34 weeks (group 2, n=41), and according to ethnic origin: Caucasians (group A, n=49) and non-Caucasians (group B, n=36). Statistical analysis, using Pearson's correlation coefficient (r) and Bland-Altman analysis were performed to evaluate correlation and agreement between TSB and TcB values. Multiple linear regression was used to control for confounders for TSB values.

RESULTS

Correlation between TSB and TcB was high. Pearson's correlation coefficients were over 0.9 in all groups (0.910, 0.908, 0.916 and 0.934, p<0.0001 in groups 1, 2, A, and B respectively). Bland-Altman plots showed acceptable and close limits of agreements (56.8/-57.7, 54.2/-67.2, 57.7/-55.8, and 51.3/-69.9μmol/L in groups 1, 2, A and B respectively) with a trend for TcB to overestimate TSB in groups 2 and B. Birth term and skin color were not identified as confounding factors for predicting TSB in multiple linear regression.

CONCLUSIONS

TcB measurements using the Draeger JM-103® device correlate significantly with TSB, regardless of term and skin color. Transcutaneous bilirubinometry seems to be a safe and cost-effective screening method for severe hyperbilirubinemia in newborns of different terms and ethnic origins.

Interscapular site for transcutaneous bilirubin measurement in preterm infants: a better and safer screening site

OBJECTIVE

To prevent bilirubin induced brain injury in the newborn, repeated blood withdrawals are necessary to ascertain bilirubin levels and institute care. Noninvasive, painless and bloodless screening using transcutaneous bilirubinometry is the standard of care for term and near term neonates but there is still debate about its use with preterm neonates. The aims of this study were to determine how transcutaneous bilirubin (TcB) level measured from the interscapular site related to total serum bilirubin (TSB) level and to compare performance of TcB from the forehead, sternum and interscapular sites in identifying preterm neonates in need of phototherapy.

STUDY DESIGN

This was a cross sectional study conducted at Groote Schuur level III neonatal unit. Over a 5-month period 122 consecutive preterm neonates <35 weeks gestational age were enrolled. TcBs were measured over the forehead, sternum and interscapular area. Pearson's correlation coefficients and differences between TSB and TcBs were computed. P-value <0.05 was considered significant.

RESULT

The median gestational age of the study participants was 31 weeks (range: 24 to 34 weeks), the median TSB level was 81.5 μmol l(-1) (range: 25 to 229 μmol l(-1)) and 45% had a TSB at the phototherapy threshold. The correlation coefficients for TcBs ranged from 0.859 to 0.929 (P<0.001). The difference between TSB and TcBs ranged from -86 to +51 μmol l(-1). With respect to initiating phototherapy, the interscapular site had the highest sensitivity of 94% and lowest false negative rate of 6%.

CONCLUSION

Using transcutaneous bilirubinometry, the interscapular site is superior and safer for screening preterm neonates.

Accuracy of transcutaneous bilirubin measurement in preterm low-birth-weight neonates

The objective of this study was to evaluate the correlation and agreement between transcutaneous and serum bilirubin among preterm low-birth-weight neonates. Neonates born at <35 weeks of gestation with birth weight <2,000 g were enrolled prospectively. Transcutaneous bilirubin (TcB) was measured at forehead, sternum, and abdomen at 24 ± 6 and 72 ± 12 h after birth and when icterus involved arms or legs (Kramer zone 4-5). Serum total bilirubin (STB) was measured by microbilimeter (STB-M) at all these time-points and by high-performance liquid chromatography (STB-H) at one randomly chosen time-point. A total of 1,619 observations were made in 256 neonates (median gestation, 34 weeks (IQR, 32-35), birth weight 1,522 ± 288 g). Overall there was excellent correlation and agreement between TcB and STB-M with TcB on forehead being most accurate (r = 0.84, mean difference, 0.3 ± 1.9 mg/dL) followed by TcB on abdomen (r = 0.73, mean difference, 1.5 ± 2.6 mg/dL) and sternum (r = 0.72, mean difference, 1.5 ± 2.6 mg/dL). TcB performed well at all three points of measurement with best correlations being observed at icterus level 4/5. Correlation between TcB and STB-H measured by high-performance liquid chromatography was less strong but significant (r = 0.59 to 0.69 at different time points of measurement).

CONCLUSIONS

TcB has good correlation and agreement with STB in preterm low-birth-weight neonates born at ≥28 weeks of gestation.

Reliability of transcutaneous bilirubin devices in preterm infants: a systematic review

BACKGROUND AND OBJECTIVE

Transcutaneous bilirubin (TcB) devices are widely used for the estimation of serum bilirubin levels in term and near-term infants. Our objective was to review the diagnostic accuracy of TcB devices in preterm infants.

METHODS

Medline, Embase, Cochrane library, Cumulative Index to Nursing and Allied Health Literature, and Scopus were searched (from database inception date until December 2012). Additional citations were identified by using the bibliographies of selected articles and from conference proceedings. The studies were included if they compared TcB with total serum bilirubin in preterm infants before phototherapy and presented data as correlation coefficients or as Bland-Altman difference plots. Data were extracted by 1 reviewer and checked for accuracy by the second reviewer. An assessment tool (quality assessment of diagnostic accuracy studies) was used for risk of bias assessments.

RESULTS

Twenty-two studies met the inclusion criteria; 21 studies reported results as correlation coefficients, with pooled estimates of r = 0.83 for each site of measurement. Pooled estimates in infants <32 weeks' gestation were similar to the overall preterm population (r = 0.89 [95% confidence interval: 0.82-0.93]). For the 2 commonly used TcB devices (ie, JM103 and BiliCheck), the results were comparable at the forehead site, although the JM103 device exhibited better correlation at the sternum. Analysis of the Bland-Altman plots (13 studies) revealed negligible bias in measurement at the forehead or sternum site by using either the JM-103 or BiliCheck device; however, the JM-103 device exhibited better precision than the BiliCheck (SD for TcB - total serum bilirubin differences: 24.3 and 31.98 µmol/L, respectively).

CONCLUSIONS

The TcB devices reliably estimated bilirubin levels in preterm infants and could be used in clinical practice to reduce blood sampling.

Point-of-care testing: where is the evidence? A systematic survey

Point-of-care testing (POCT) has had rapid technological development and their use is widespread in clinical laboratories to assure reduction of turn-around-time and rapid patient management in some clinical settings where it is important to make quick decisions. Until now the papers published about the POCT have focused on the reliability of the technology used and their analytical accuracy. We aim to perform a systematic survey of the evidence of POCT efficacy focused on clinical outcomes, selecting POCT denoted special analytes characterized by possible high clinical impact. We searched in Medline and Embase. Two independent reviewers assessed the eligibility, extracted study details and assessed the methodological quality of studies. We analyzed 84 studies for five POCT instruments: neonatal bilirubin, procalcitonin, intra-operative parathyroid hormone, troponin and blood gas analysis. Studies were at high risk of bias. Most of the papers (50%) were studies of correlation between the results obtained by using POCT instruments and those obtained by using laboratory instruments. These data showed a satisfactory correlation between methods when similar analytical reactions were used. Only 13% of the studies evaluated the impact of POCT on clinical practice. POCT decreases the time elapsed for making decisions on patient management but the clinical outcomes have never been adequately evaluated. Our work shows that, although POCT has the potential to provide beneficial patient outcome, further studies may be required, especially for defining its real utility on clinical decision making.

Measuring transcutaneous bilirubin: a comparative analysis of three devices on a multiracial population

Background

Hyperbilirubinemia can lead to potentially irreversible bilirubin-induced neurotoxicity. Transcutaneous bilirubin (TcB) determination has become a valuable aid in non invasive screening of neonatal jaundice.

The aim of this study is to compare the performance of three most widespread transcutaneous bilirubinometers on a multiracial population of term and late pre-term neonates.

Methods

Bilirubin concentration was determined using traditional photometric determination and transcutaneously with Bilicheck, BiliMed and JM-103, in random order.

Total serum bilirubin (TSB) was determined over a wide concentration range (15,8–0,7 mg/dl) with a mean of 9,5 mg/dl. Related TcB values using Bilicheck (TcB-BC), BiliMed (TcB-BM), and JM-103 (TcB-JM) are reported in Table 1.

Results

A multiracial population of 289 neonates was enrolled with a gestational age ranging from 35 to 41 weeks; birth weight ranging from 1800to 4350 grams; hours of life ranging from 4 to 424. In the total study population correlation analysis using Pearson coefficients showed good results for Bilicheck (r = 0.86) and JM-103 (r = 0.85) but poor for BiliMed (r = 0,70). Similar results were found for the non-Caucasian neonates subgroup. Bilicheck and JM-103 had a greater area under the curve than BiliMed when TSB =14 mg/dl was chosen as a threshold value both for the total study population and the non-Caucasian subgroup.

Conclusions

Bilicheck and JM-103, but not BiliMed, are equally reliable screening tools for hyperbilirubinemia in our multiracial neonatal population.

Is it worthwhile using a transcutaneous bilirubinometer in the nursery?

Jaundice is a potential threat to neonatal health and/or life. The advantages and limitations of transcutaneous determination of bilirubin concentration and current devices are briefly discussed in this paper.

Assessing jaundice in infants of 35-week gestation and greater

PURPOSE OF REVIEW

In 2004, the American Academy of Pediatrics officially recommended universal predischarge risk assessment for severe neonatal hyperbilirubinemia with the goal of minimizing subsequent risk of chronic bilirubin encephalopathy (formerly known as kernicterus). In this article, we review recent research regarding jaundice predischarge risk assessment, current expert recommendations for universal predischarge bilirubin screening, and concerns expressed in the literature regarding these recommendations.

RECENT FINDINGS

A group of experts have recently recommended universal predischarge bilirubin screening to identify newborns at risk for developing severe neonatal hyperbilirubinemia. In contrast, the United States Preventive Services Task Force states that there is insufficient evidence to make this recommendation. Transcutaneous bilirubinometry has emerged as a noninvasive, quick method to screen for neonatal hyperbilirubinemia, although refinement and validation of transcutaneous bilirubin nomograms are needed. Newer studies suggest that the combined use of a predischarge bilirubin and gestational age risk assessment offers a simple, objective, and accurate way to identify infants at risk for subsequent, severe hyperbilirubinemia.

SUMMARY

All newborns should be systematically assessed for risk of developing severe hyperbilirubinemia prior to hospital discharge. Although limited data exist to recommend its use universally, predischarge bilirubin screening should be considered given recent expert opinion. The role of transcutaneous bilirubinometry remains promising, although further research evaluating and validating its use in varied and diverse populations is imperative. Combined models of risk assessment may offer the best approach to identifying infants at risk for subsequent, severe hyperbilirubinemia.