A Novel Icterometer for Hyperbilirubinemia Screening in Low-Resource Settings

Abstract

BACKGROUND: Severe neonatal hyperbilirubinemia (>20 mg/dL) affects ∼1 million infants annually. Improved jaundice screening in low-income countries is needed to prevent bilirubin encephalopathy and mortality. METHODS: The Bili-ruler is an icterometer for the assessment of neonatal jaundice that was designed by using advanced digital color processing. A total of 790 newborns were enrolled in a validation study at Brigham and Women’s Hospital (Boston) and Sylhet Osmani Medical College Hospital (Sylhet, Bangladesh). Independent Bili-ruler measurements were made and compared with reference standard transcutaneous bilirubin (TcB) and total serum bilirubin (TSB) concentrations. RESULTS: Bili-ruler scores on the nose were correlated with TcB and TSB levels (r = 0.76 and 0.78, respectively). The Bili-ruler distinguished different clinical thresholds of hyperbilirubinemia, defined by TcB, with high sensitivity and specificity (score ≥3.5: 90.1% [95% confidence interval (CI): 84.8%–95.4%] and 85.9% [95% CI: 83.2%–88.6%], respectively, for TcB ≥13 mg/dL). The Bili-ruler also performed reasonably well compared to TSB (score ≥3.5: sensitivity 84.5% [95% CI: 79.1%–90.3%] and specificity 83.2% [95% CI: 76.1%–90.3%] for TSB ≥11 mg/dL). Areas under the receiver operating characteristic curve for identifying TcB ≥11, ≥13, and ≥15 were 0.92, 0.93, and 0.94, respectively, and 0.90, 0.87, and 0.86 for identifying TSB ≥11, ≥13, and ≥15. Interrater reliability was high; 97% of scores by independent readers fell within 1 score of one another (N = 88). CONCLUSIONS: The Bili-ruler is a low-cost, noninvasive tool with high diagnostic accuracy for neonatal jaundice screening. This device may be used to improve referrals from community or peripheral health centers to higher-level facilities with capacity for bilirubin testing and/or phototherapy.