Author: Brody H. Foy, Assistant Professor of Laboratory Medicine and Pathology, University of Washington

If you’ve ever had a doctor order a blood test for you, chances are that they ran a complete blood count, or CBC. One of the most common blood tests in the world, CBC tests are run billions of times each year to diagnose conditions and monitor patients’ health. But despite the test’s ubiquity, the way clinicians interpret and use it in the clinic is often less precise than ideal. Currently, blood test readings are based on one-size-fits-all reference intervals that don’t account for individual differences. I am a mathematician at the University of Washington School of Medicine, and my…