B-132 Within limits - is my thyroid just plump, or are these reference intervals telling me something?

Abstract

Abstract Background Replacing immunoassay equipment brings challenges in the implementation of reference intervals (RIs). In 2023, Cork University Hospital (CUH) replaced Abbott Architect immunoassay analysers with Beckman Coulter DxI 9000 units. The manufacturer’s recommended reference intervals were applied as the DxI 9000 is new to the market. CUH reports ≈100,000 immunoassay results per month. Methods A minimum of 45 adult patient samples were run on the Abbott and Beckman Coulter platforms for each of sixteen analytes as part of method verification following the requirements of ISO 15189 and CLSI. The slope and intercept of the Passing-Bablok regression analyses were used to transform the Abbott RI and the newly modelled RIs compared to those provided by Beckman Coulter. Results Conclusions: While the manufacturer’s RI was adopted initially, the modelled data have shown that for three analytes (PTH, HCG, Free T4) the modelled RI differs significantly from the manufacturer’s. This was judged by how patients would theoretically be classified. For these assays it is necessary to closely monitor patients in the initial three months post-go-live to ensure that the RIs are clinically acceptable. A comprehensive dialogue was undertaken with clinicians before and after the implementation to ensure they were aware of the changes. All modelling was performed on adult patient data. However, CUH has a large paediatric patient cohort, and for this group, the same RI transformations were performed, and discussions were held with paediatric teams. Introducing new platforms and RIs requires careful planning, education and an open dialogue with clinicians to ensure no compromise to patient care. RIs should be reviewed frequently for appropriateness.