Overdiagnosis of Newborn Hyperbilirubinemia: A Natural Experiment in Quality Improvement Fundamentals

Two hospitals noted increased newborn hyperbilirubinemia coinciding with an undisclosed total serum bilirubin (TSB) assay change. Clinicians rapidly applied quality improvement methodologies to ascertain increased jaundice evaluations, readmissions, and possible safety issues.

In January 2020, 2 hospitals (A and B) transitioned to a new method of measuring TSB using a new clinical chemistry analyzer (Siemens Atellica CH), which measured TSB by vanadate oxidase assay instead of the previous diazo assay. Five affiliated hospitals (C-G) continued to utilize the diazo assay. This natural experiment led to a comparison of data across the 7 hospitals. We analyzed: (1) TSB levels, (2) hospital hyperbilirubinemia readmissions, and (3) paired TSB measurements comparing the diazo assay and vanadate oxidase method.

Compared to the 2019 baseline, Hospitals A and B had a significant increase in TSBs ≥17.0 mg/dl and TSBs ≥20 mg/dl in 2020; Hospitals C-G did not. Readmissions for phototherapy significantly increased in hospitals A and B in 2020 compared to 2019. Paired blood samples showed bias-elevated TSBs by vanadate assay compared to the diazo method. By 2021, the laboratory resumed processing TSB samples by diazo assay, and the frequency of elevated TSBs and hyperbilirubinemia readmissions returned to 2019 levels.

Factitious TSB elevation related to an assay change significantly increased newborn hyperbilirubinemia evaluations and phototherapy readmissions. Imbedded quality improvement methodologies of careful structure, process, and outcomes review hastened resolution.