Multidimensional Reliability Assessment of the Hepato‐Renal Index for Pediatric Metabolic Dysfunction‐Associated Fatty Liver Disease Diagnosis

ABSTRACT Objective To quantitatively evaluate the agreement of the HRI measurements. Materials and Methods In 2024, 307 children underwent ultrasonography by an experienced sonographer (> 5 years). ICC assessed reproducibility between longitudinal (HRI L ) / transverse (HRI T ) planes, devices, and intra‐operator measurements. Inter‐operator reproducibility was determined by a junior sonographer in 40 children; systematic bias was quantified by Bland–Altman analysis. Results HRI measurements demonstrated high reliability: among 307 subjects, HRI L (1.39 ± 0.55) and HRI T (1.36 ± 0.67) showed no significant difference ( t = 1.29, p = 0.20; ICC = 0.84, 95% CI 0.80–0.87); in 70 subjects using different ultrasound systems, HRI (1.68 ± 0.64, 1.69 ± 0.64, 1.71 ± 0.74) exhibited no inter‐device variation ( H = 0.31, p = 0.86; ICC = 0.95, 95% CI 0.93–0.97). Intra‐operator reproducibility was consistent for Operator 1 (baseline: 1.54 ± 0.65 vs. 2‐week: 1.54 ± 0.56; t = −0.01, p = 0.99; ICC = 0.92, 95% CI 0.84–0.96) and Operator 2 (1.27 ± 0.50 vs. 1.30 ± 0.50; t = −0.62, p = 0.53; ICC = 0.86, 95% CI 0.75–0.92). Inter‐operator analyses agreed between Operator 2 baseline (1.27 ± 0.50) and Operator 1 baseline (1.31 ± 0.61; t = 0.72, p = 0.48; ICC = 0.80, 95% CI 0.65–0.89), and Operator 2 2‐week (1.30 ± 0.50) and Operator 1 baseline ( t = 0.30, p = 0.77; ICC = 0.86, 95% CI 0.75–0.92). Measurement frequency assessments revealed consistency for Operator 1 baseline (first‐three: 1.55 ± 0.58 vs. five: 1.54 ± 0.65; t = −0.18, p = 0.86; ICC = 0.91, 95% CI 0.83–0.95), Operator 2 baseline (1.19 ± 0.54 vs. 1.27 ± 0.50; t = 1.74, p = 0.09; ICC = 0.84, 95% CI 0.71–0.91), and Operator 2 2‐week (1.31 ± 0.60 vs. 1.30 ± 0.50; t = −0.27, p = 0.79; ICC = 0.87, 95% CI 0.77–0.93). Conclusion HRI demonstrates high stability and reproducibility across platforms, supporting MAFLD early diagnosis.