Age- and Sex-Dependent Interpretation of C-Reactive Protein Cutoffs: A Sixteen-Year Large-Scale Clinical Laboratory Data Analysis

Background/Objectives: The clinical meaning of a given C-reactive protein (CRP) threshold may differ by age and sex; however, a comprehensive framework to elucidate demographic differences is lacking. We examined age- and sex-related differences in the central tendency and upper tail of the CRP distribution and their implications for fixed-threshold interpretation. Methods: We retrospectively analyzed 1,845,151 serum CRP results from 336,360 individuals at a single tertiary-care hospital. Quanti