Validation of transcutaneous bilirubinometry during phototherapy for detection and monitoring of neonatal jaundice in a low-income setting

Background: Severe neonatal jaundice (SNJ) and the associated long-term health sequelae are a significant problem in low-income countries (LIC) where measurement of total serum bilirubin (TSB) is often unavailable. Transcutaneous bilirubinometry (TcB) provides the opportunity for non-invasive, point-of-care monitoring. Few studies have evaluated its agreement with TSB levels during phototherapy in LIC. Aim: To determine agreement between TcB and TSB during phototherapy in a Haitian newborn population and to establish whether TcB can be safely used to guide treatment during phototherapy when TSB is unavailable. Methods: A single-centre prospective study (February to May 2017) in Cap Haitien, northern Haiti was undertaken. Newborns <7 days of age with clinically detected jaundice were eligible for inclusion. A TcB device (JM-103) was used to screen for newborn jaundice along with a parallel TSB. A strip of black tape was placed across the sternum during phototherapy and uncovered for subsequent TcB measurements. Decisions about phototherapy treatment were based upon UK National Institute of Clinical Excellence (NICE) threshold criteria. Paired TSB and TcB measurements were compared using Bland-Altman methods. Results: The final analysis included 70 parallel TSB/TcB measurements from 35 infants within the first 5 days of life. Nineteen (54.3%) were male and 12 (34.3%) were <35 weeks. Thirty-two (91.4%) were receiving phototherapy. There was good agreement between TSB and TcB. Compared with TSB, TcB tended to over-estimate bilirubin (mean difference 11.1 mu mol/L, 95% CI -10.2-32.5 mu mol/L). However, at higher bilirubin levels (>250 mu mol/L), TcB tended to under-estimate bilirubin compared with TSB and the difference increased. Conclusion: In an LIC setting in which serum bilirubin testing is not commonly available, TcB demonstrates good agreement with TSB and can be safely used to guide jaundice treatment during phototherapy but can lead to over-treatment at lower bilirubin levels and are more inaccurate at higher levels. For TcB levels >250 mu mol, confirmation with serum bilirubin should be performed, if available, to avoid under-estimation.