The 10+1 Santorini Conference

Several national surveys have reported wide variation in reference intervals across healthcare centers in certain regions, even those using the same analytical platform and reagents for the same assay.There is a high risk of inappropriate test result interpretation when reference intervals are not appropriately harmonized.The Canadian Society for Clinical Chemistry (CSCC) Working Group on Reference Interval Harmonization was established in 2015 to develop evidence-based harmonized/common reference intervals and support their implementation in laboratories across Canada.Harnessing the power of big data, laboratory results were collected across populations and testing platforms to derive common adult RIs for 16 biochemical markers.A novel comprehensive approach was established, including: (1) analysis of big data from community laboratories across Canada; (2) statistical evaluation of age, sex, and analytical differences; (3) derivation of hRIs using the refineR method; and (4) verification of proposed harmonized reference intervals across nine laboratories with different instrumentation using serum and plasma samples collected from healthy Canadian adults.Harmonized RIs were calculated for all assays using the refineR method, except free thyroxine.Derived harmonized reference intervals met proposed verification criterion across nine laboratories and five manufacturers for alkaline phosphatase, albumin (BCG), chloride, LDH, magnesium, phosphate, potassium (serum), total protein (serum).Further investigation is needed for select analytes due to lower verification in one or more laboratory (albumin (BCP), calcium, total CO2, total bilirubin, sodium) or concern regarding harmonized reference intervals that were considered too wide (alanine aminotransferase, creatinine, TSH).In this presentation, we will discuss the work completed by the Working Group on Reference Interval Harmonization in Canada, challenges encountered, and future plans to support implementation.