Eliminating race-based reference ranges in haematology: a call to action.

In haematology, as in all of medicine, the use of reference intervals for laboratory variables is essential to define disease states and inform treatment decisions. There are many haematological variables, including haemoglobin, mean corpuscular volume, absolute neutrophil count, and iron indices, that are often reported to be different on the basis of a person's race or ethnicity. Although there are many haematological conditions with a genetic basis, such that it is appropriate to consider ancestry in the diagnostic algorithm, defining pathology on the basis of a social construct such as race is unacceptable. The inclusion of separate thresholds or simple statements that so-called normal values vary by race further validates the common misperception that there are physiological differences between Black and white patients. These statements might have downstream effects on diagnostic and treatment decisions that exacerbate existing racial health disparities. In this Viewpoint, we argued for the removal of race-based reference intervals across haematology.