In settings where laboratory facilities are scarce, drawing blood for a serum bilirubin test is not always practical. A new cross-sectional study from Bhutan, published in BMC Pediatrics, examined whether two non-invasive tools, a transcutaneous bilirubinometer (TcB) and a simple icterometer, could stand in for capillary bilirubin measurement in jaundiced newborns.
The research was carried out at the Community Health Unit of Jigme Dorji Wangchuck National Referral Hospital in Thimphu between December 2021 and November 2022. Neonates presenting for postnatal care were first screened with the TcB device. Babies whose TcB values exceeded the age-specific phototherapy threshold of the American Academy of Pediatrics guideline were recruited by convenience sampling and then underwent both icterometer assessment and capillary bilirubin measurement using the Toitu BL-200 bilirubinometer, which served as the reference method.
The study enrolled 723 infants, of whom 683, or 94.5 percent, were term babies with a mean gestational age of 39.0 plus or minus 1.4 weeks. Mean capillary bilirubin was 13.8 plus or minus 2.1 mg/dL, while mean TcB was considerably higher at 20.1 plus or minus 2.4 mg/dL. The median icterometer score was 3.0, with an interquartile range of 2.5 to 3.5.
When the researchers compared how closely each screening tool tracked the reference measurement, TcB performed better. TcB showed a stronger correlation with capillary bilirubin than the icterometer did, with correlation coefficients of 0.723 versus 0.601, both statistically significant with p below 0.001. However, TcB systematically overestimated capillary bilirubin by a mean of 6.30 mg/dL, with a 95 percent confidence interval of 6.18 to 6.42 mg/dL, and the 95 percent limits of agreement ranged from 3.00 to 9.60 mg/dL.
The team also assessed how well each method discriminated between infants above and below various bilirubin thresholds using receiver operating characteristic curve analysis. The area under the curve for TcB at capillary bilirubin thresholds of 11, 13, 15, and 17 mg/dL was 0.847, 0.846, 0.891, and 0.912 respectively. The corresponding AUC values for the icterometer were lower, at 0.747, 0.765, 0.824, and 0.885.
At the highest threshold examined, 17 mg/dL, the two tools performed more comparably. An icterometer cutoff score of 3.5 or higher yielded a sensitivity of 91.2 percent and a specificity of 67.4 percent, while a Youden-derived TcB cutoff of 21.9 mg/dL or higher gave 87.7 percent sensitivity and 84.1 percent specificity. Notably, the difference in AUC between the two methods at this threshold was not statistically significant, with a delta AUC of 0.027 and a 95 percent confidence interval spanning from minus 0.027 to 0.081, and a p value of 0.331.
The authors conclude that the icterometer shows potential as a low-cost screening tool for neonatal hyperbilirubinemia, particularly in settings where TcB may not be readily available.
The study’s authors are careful to note important caveats. They state that further validation against total serum bilirubin using age- and gestational-specific thresholds is needed before the icterometer can be recommended for routine clinical implementation. The reference method used here was capillary bilirubin measured with the Toitu BL-200 device rather than total serum bilirubin, and the cohort was drawn from a single hospital unit in Thimphu using convenience sampling, which may limit how broadly the results apply.
For clinicians in resource-constrained settings, the study offers a measured but encouraging signal: a simple, inexpensive tool may help identify newborns who need closer bilirubin assessment, while acknowledging that more rigorous validation remains a prerequisite before routine use.
Subject of Research: Diagnostic accuracy of non-invasive bilirubin screening methods in jaundiced neonates in Bhutan
Article Title: Diagnostic accuracy of transcutaneous bilirubinometry and icterometry compared with capillary bilirubin measurement in neonates with jaundice in Bhutan: a cross-sectional study
Article References: Zam, C. L., Yoezer, J., Chhezom, K., Chhetri, K., & Mynak, M. L. (2026). Diagnostic accuracy of transcutaneous bilirubinometry and icterometry compared with capillary bilirubin measurement in neonates with jaundice in Bhutan: a cross-sectional study. BMC Pediatrics. https://doi.org/10.1186/s12887-026-07839-7
Image Credits: AI Generated
DOI: 10.1186/s12887-026-07839-7
Keywords: neonatal jaundice, hyperbilirubinemia, transcutaneous bilirubinometry, icterometer, capillary bilirubin, diagnostic accuracy, Bhutan, screening, cross-sectional study, pediatrics, resource-limited settings, ROC analysis
News Source: Harold Sullivan. (October 28, 2026). Icterometer shows promise as low-cost screen for newborn jaundice in Bhutan. Scienmag.
