Implementation of a reformulated Roche® bilirubin Gen.3 reagent did not affect the relationship between BiliChek transcutaneous and Roche total serum bilirubin

Abstract Objective Determine whether introduction of a reformulated bilirubin reagent, the Roche bilirubin Gen.3 assay, changed the relationship between BiliChek transcutaneous bilirubin (TcB) and total serum bilirubin (TSB). Design and methods TcB results from term infants in the level 1 nursery obtained within one hour of a TSB were reviewed over two periods, six months before and after the conversion from the previous generation Roche bilirubin reagent to the new Roche Gen.3 bilirubin assay. TcB measurements were performed using BiliChek transcutaneous devices (Respironics, Marietta GA). Distribution of TSB results, and TcB minus TSB bias, were compared before and after introduction of the reformulated Roche bilirubin Gen.3 assay. Median and interquartile range (IQR) TSB values and bias were calculated. A statistical difference between median TSB values and bias were assessed using Man-Whitney test. Results A total of 301 paired TcB and TSB results were obtained, 172 before and 129 after implementation of the reformulated Roche bilirubin Gen.3 reagent. Median (IQR) TSB was 7.8 (6.8–8.7)mg/dL (133.3 (116.3–148.8) μmol/L) before and 7.6 (6.7–8.4)mg/dL (130 (114.6–143.6)μmol/L) after implementation of the reformulated reagent ( p  = .1373). Median (IQR) bias between TcB and TSB was 2.9 (2.2–3.7) mg/dL (49.6 (37.6–63.3)μmol/L) before the reformulated reagent was implemented; and did not change at 2.9 (2.1–3.9) mg/dL (49.6 (35.9–66.7)μmol/L) after implementation ( p  = .8242). Conclusion Implementation of the reformulated Roche bilirubin Gen.3 reagent did not affect the relationship between BiliChek transcutaneous and total serum bilirubin; thus no changes were needed to the neonatal TcB screening protocol as a result of the new bilirubin reagent.