BiliChek transcutaneous bilirubin meter overestimates serum bilirubin as measured by the Doumas reference method

Objectives: To determine the relationship between BiliChek TcB (Respironics, Marietta GA) and Doumas reference serum or plasma total bilirubin (TSB). Design and methods: Pooled samples with values assigned by the Doumas reference method were used to establish the relationship between a local laboratory and reference Doumas TSB. We then established the relationship between TcB and TSB in the 3. months before and after reassignment of calibrator setpoints undertaken to match the local laboratory to Doumas reference bilirubin values. Results: Before calibrator setpoint reassignment TSB as measured in our laboratory overestimated Doumas reference bilirubin. After calibrator adjustment laboratory TSB was within 1.7-6.8μmol/L (0.1-0.4. mg/dL) of Doumas reference values. Mean bias between BiliChek TcB and TSB was 42.8 ± 22.2 μmol/L (2.5 ± 1.3 mg/dL) (n=94) before and 49.6 ± 22.2 μmol/L (2.9 ± 1.3 mg/dL) (n=115) after calibration adjustment. Conclusions: BiliChek TcB significantly overestimates TSB as measured by the Doumas reference method.