Establishment of sex-specific reference intervals for PIVKA-II in Southwest China: A real-world data analysis

Objective We aim to establish the sex-related reference intervals (RIs) of PIVKA-II in southwest China by indirect method with the real-world data. Methods Between 29 July 2016 and 5 February 2024, PIVKA-II test data were collected from 120,780 healthy adult participants (aged 18 to 97 years) in the Laboratory Information System (LIS) of West China Hospital to establish reference intervals. Additionally, a validation group comprised of 2068 healthy adults was evaluated using the same detection algorithm and platform. Following the CLSI EP28-A3 guideline, Box-Cox transformation was applied for normal transformation, and outliers were identified using the Tukey method. Furthermore, we employed the standard normal deviate test (z-test) recommended by Harris and Boyd to determine whether to stratify reference intervals by age and sex subclasses. Results We successfully established population-specific RI for PIVKA-II in southwest China using an indirect method. By utilizing a robust dataset and conducting rigorous statistical analyses, we delineated sex-specific RIs, with values of 0–35 mAU/mL for males and 0–29 mAU/mL for females according to the normal distribution method, and 0–32 mAU/mL for males and 0–28 mAU/mL for females using the non-parametric method. These intervals are more suitable for the local population than those derived from manual methods. Conclusion These RIs provide valuable guidance for the accurate interpretation of PIVKA-II levels in the local population.