Blood tests are fundamental to modern medicine, and are typically interpreted against broad reference ranges, based on population averages. Yet this standard approach overlooks a crucial point — many blood measurements (biomarkers) are highly individualized and regulated around unique stable values called setpoints, which differ between people. For many people, their ‘normal’ blood values fall within a narrow range — one that is much smaller than the population-based reference range1. Writing in Nature, Foy et al.2 present evidence that underscores the importance of these personalized setpoints, analysing decades of blood-test data across nine key parameters. The authors’ findings suggest that integrating personalized reference intervals into clinical diagnostics could bring about a new level of precision medicine.
Competing Interests
S.J.R.M. received research grants, research support, consultancy fees and lecture fees from diagnostic companies, including Roche Diagnostics, Abbott Laboratories and Werfen, all paid to his employer (Maastricht University Medical Center), and unrelated to the topic discussed in this manuscript. K.M.A. has served on advisory boards for Roche Diagnostics, Radiometer, Siemens Healthineers and SpinChip, and received consultant honoraria from CardiNor, lecturing honorarium from Siemens Healthineers, Roche Diagnostics, Mindray and Snibe Diagnostics and research grants from Siemens Healthineers and Roche Diagnostics. K.M.A. is also Associate Editor of Clinical Biochemistry and Chair of the IFCC Committee of Clinical Application of Cardiac Bio-markers.