Will the Bili-ruler Rule?

Novel, Low-cost Device Highly Accurate at Screening Newborn Jaundice

Neonatal hyperbilirubinemia affects up to 80% of newborns in their first week of life. Each year, approximately one million infants around the world are affected with severe hyperbilirubinemia. When diagnosed early, it is usually treatable with high-intensity phototherapy. Left undiagnosed or untreated, the condition can cause irreversible brain damage or even death. Such complications often arise in low- and middle-income countries (LMICs), where one-third of infants die from the condition.

In these countries, a major challenge in managing hyperbilirubinemia is the failure to recognize its severity before the onset of irreversible symptoms. However, in a recent issue of Pediatrics, researchers from Brigham and Women’s Hospital reported the design and validation of the Bili-ruler, a tool for frontline health workers to screen for hyperbilirubinemia in low-resource settings.

Transcutaneous bilirubin instruments are available in high-income settings, but they cost over $7,000 and are thus not affordable in most low-income settings.

If a baby with hyperbilirubinemia is not diagnosed, or diagnosed too late, there are few options that can be done before the effects become permanent, say the researchers.

To address this, they designed the Bili-ruler to improve identification of clinically severe hyperbilirubinemia among newborns in low-resource settings. The portable, handheld “ruler” measures the degree of jaundice by using six color strips arranged in a stepwise gradient of yellow shades.

The user presses the Bili-ruler against the infant’s skin, and views the underlying skin tone through a circular window enclosed by a uniform color strip. The process is repeated for all six colors, then the user selects the score that corresponds to whichever color most closely matches the infant’s skin tone.

To validate the Bili-ruler across diverse populations, the researchers recruited a total of 790 newborns younger than 28 days from Brigham and Women’s Hospital and the Sylhet Osmani Medical College Hospital, in Sylhet, Bangladesh.

The team used the Bili-ruler to assess for jaundice together with clinical measures of transcutaneous bilirubin (TcB) and total serum bilirubin (TSB) levels. Bili-ruler measurements were obtained from the forehead, nose, abdomen, palms, or soles of the feet, without previous knowledge of bilirubin levels. The scores were then compared with TcB and TSB.

The Bili-ruler demonstrated high diagnostic accuracy and validity, with strongest positive correlations between measurements taken on the nose with bilirubin concentrations measured by both TcB and TSB. Also, the nose measurements had high validity, sensitivity, and specificity for identifying hyperbilirubinemia of several different thresholds.

Results seemed consistent between infants of varying skin tones, an important consideration for Bili-ruler use in multi-ethnic populations. But as the largest populations validated were south Asian and white, the researchers hope to expand the Bili-ruler’s validation among other ethnicities, specifically Hispanic and black populations.

Source: EurekAlert!, May 20, 2019