Establishment of gender– and age–related reference intervals for serum uric acid in adults based on big data from Zhejiang Province in China

Abstract Objectives This study utilized large-scale health examination data to explore gender– and age–specific reference intervals (RIs) for serum uric acid (UA) using indirect methods and assessed the consistency of different approaches. Methods UA data were collected from a hospital in Zhejiang Province, China. The test set covered January 2019 to December 2023, with a validation set from January to June 2024. Various methods – EP28 nonparametric (EP28-NP), parametric (EP28-P), TMC, refineR, and Kosmic – were used to establish gender– and age–specific RIs. Continuous age-based RIs were derived using the Generalized Additive Model for Location Scale and Shape (GAMLSS). Validation rates were calculated for each method using the validation set. Results Using EP28-NP as the benchmark, other methods showed similar UA RIs (bias ratios ≤0.375, except for one group), with Kosmic, refineR, and TMC yielding slightly higher values than EP28-NP and EP28-P. For males, UA RIs varied by age: 19–42 years (256–537 μmol/L), 43–66 years (235–513 μmol/L) and ≥67 years (214–515 μmol/L), with validation rates ranging from 94.05 to 96.50 %. Male continuous RIs declined from ages 20–79 and then gradually increased after age 80. For females, UA RIs were age-dependent: 19–48 years (169–374 μmol/L), 49–74 years (178–405 μmol/L), and ≥75 years (186–470 μmol/L), with validation rates ranging from 92.70 to 96.80 %. Female continuous RIs decreased from ages 20–48, then increased significantly from age 49 onward. Conclusions Three indirect methods and two EP28 methods demonstrated good consistency in establishing UA RIs. Males had higher RIs than females, and RIs showed a non-linear correlation with age.