Degree of Discordance Between FIB-4 and Transient Elastography: An Application of Current Guidelines on General Population Cohort

Abstract

Background and Aims

In the AGA/AASLD Clinical Care Pathway, Fibrosis-4 index (FIB-4) is used to stratify patients at risk for metabolic-dysfunction-associated-steatotic liver disease (MASLD) as low-, indeterminate-, or high-risk for developing advanced liver fibrosis. We assessed the performance of FIB-4 in a general population.

Methods

Using the 2017-2020 National Health and Nutrition Examination Surveys (NHANES) dataset, we selected subjects ≥18 years who had FibroScan® data. We followed AGA/AASLD guidelines to identify subjects with characteristics that place them at risk for MASLD-associated liver fibrosis. Other causes of liver disease were excluded. Our final cohort had 3741 subjects. We then categorized these subjects based on recommended FIB-4 cutoffs. FibroScan® liver stiffness measurement (LSM) served as the outcome measurement.

Results

Amongst the 2776 (74.2%) subjects classified as low-risk by FIB-4, 277 subjects (10%) were not classified at low-risk by LSM and 75 subjects (2.7%) were classified as high-risk by LSM. Amongst the 86 subjects classified as high-risk by FIB-4, 68 subjects (79.1%) were not at high-risk by LSM and 54 subjects (62.8%) were at low-risk by LSM. Subjects misclassified by FIB-4 as low-risk were older; had a higher BMI, waist circumference, glycohemoglobin A1c level, ALT, AST, diastolic blood pressure, CAP score, white blood cell (WBC) count, alkaline phosphatase, and fasting glucose level; but had lower HDL and albumin level (all p<0.05). Misclassified subjects were also more likely to have prediabetes/diabetes.

Conclusion

Using FIB-4 in the AGA/AASLD guidelines to risk-stratify subjects at risk for MASLD-associated fibrosis results in many subjects being misclassified into the low and high-risk categories. Therefore, it may be worthwhile considering caution in interpretation and/or alternative strategies.