Routine laboratory model for identifying significant fibrosis in chronic hepatitis B

Figure 1 Construction of the development, external validation, and exploratory cohorts. The development cohort was derived from two tertiary hospitals in Zhejiang Province, and an independent biopsy-confirmed cohort from the First Affiliated Hospital of Zhejiang University served as external validation. A population-based exploratory cohort was obtained from National Health and Nutrition Examination Survey 2011-2020 and included individuals with evidence of hepatitis B virus exposure. Because liver biopsy is unavailable in National Health and Nutrition Examination Survey, fibrosis status was approximated using a conservative aspartate aminotransferase to platelet ratio index/fibrosis-4-based algorithm. After data harmonization and exclusion of participants with missing key variables or other causes of liver disease, the final cohorts were used for model development and evaluation. HBV: Hepatitis B virus; NHANES: National Health and Nutrition Examination Survey; APRI: Aspartate aminotransferase to platelet ratio index; AST: Aspartate aminotransferase; FIB-4: Fibrosis-4; ALT: Alanine aminotransferase; PLT: Platelet.