Healthcare & Clinical
NAFLD Fibrosis Score (NFS) Noninvasive MASLD Liver Fibrosis Formula
Calculate Paul Angulo’s validated NAFLD Fibrosis Score NFS = -1.675 + 0.037*Age + 0.094*BMI + 1.13*IFG_DM + 0.99*(AST/ALT) - 0.013*Platelets - 0.66*Albumin to rule out (< -1.455) or rule in (> 0.675) F3–F4 advanced liver fibrosis.
Screen metabolic fatty liver (NAFLD / MASLD) for F3–F4 bridging fibrosis using routine clinic labs!
Liver biopsy cannot be performed on hundreds of millions of adults with metabolic dysfunction-associated steatotic liver disease (MASLD / NAFLD). Paul Angulo et al. (2007, Hepatology) derived and validated the noninvasive 6-variable NAFLD Fibrosis Score: NFS = -1.675 + 0.037 * Age (yr) + 0.094 * BMI (kg/m^2) + 1.13 * IFG_or_Diabetes (1 if Yes, 0 if No) + 0.99 * (AST / ALT) - 0.013 * Platelets (x10^9/L) - 0.66 * Albumin (g/dL)!
Notice how every physiological term tracks portal hypertension and hepatic synthetic decline: rising AST/ALT ratio, falling splenic-sequestered platelets, falling serum albumin, and insulin resistance push NFS upward! AASLD/EASL hepatology pathways apply two validated cutoffs: NFS < -1.455 excludes F3–F4 advanced fibrosis with ~93% negative predictive value (F0–F2 Low Risk), NFS > 0.675 rules in F3–F4 advanced bridging fibrosis/cirrhosis with ~90% positive predictive value, and indeterminate scores (-1.455 to 0.675) proceed to FibroScan transient elastography!
| NAFLD Fibrosis Score (NFS) Band | Histologic Fibrosis Stage | Clinical Hepatology Pathway |
|---|---|---|
| NFS < -1.455 (e.g., -3.416) | F0–F2 (Advanced Fibrosis Excluded) | Low Risk — Primary-Care Lifestyle & Periodic Repeat |
| -1.455 <= NFS <= 0.675 | Indeterminate Gray Zone | Order VCTE FibroScan or ELF Blood Panel |
| NFS > 0.675 (e.g., +1.392) | F3–F4 Advanced Fibrosis / Cirrhosis | High Risk — Refer to Hepatology Specialist |
Angulo (2007) NAFLD Fibrosis Score (NFS)
Evaluates the 6-parameter linear regression score while guarding against zero/negative labs or BMI.
=IF(OR(B2 < 18, B3 <= 10, AND(B4 <> 0, B4 <> 1), B5 <= 0, B6 <= 0, B7 <= 0, B8 <= 0), "Invalid Liver Lab Inputs", ROUND(-1.675 + 0.037 * B2 + 0.094 * B3 + 1.13 * B4 + 0.99 * (B5 / B6) - 0.013 * B7 - 0.66 * B8, 3))F3–F4 Advanced Liver Fibrosis Risk Stratification
Classifies NFS against the < -1.455 exclusion cutoff and > 0.675 high-probability F3–F4 cutoff.
=IF(OR(B2 < 18, B3 <= 10, AND(B4 <> 0, B4 <> 1), B5 <= 0, B6 <= 0, B7 <= 0, B8 <= 0), "Invalid Liver Lab Inputs", IF((-1.675 + 0.037 * B2 + 0.094 * B3 + 1.13 * B4 + 0.99 * (B5 / B6) - 0.013 * B7 - 0.66 * B8) > 0.675, "High Probability F3-F4 Advanced Fibrosis (> 0.675)", IF((-1.675 + 0.037 * B2 + 0.094 * B3 + 1.13 * B4 + 0.99 * (B5 / B6) - 0.013 * B7 - 0.66 * B8) < -1.455, "Low Risk: F0-F2 Advanced Fibrosis Excluded (< -1.455)", "Indeterminate (-1.455 to 0.675): Order FibroScan")))Try the example
Use the original values or change them to test your understanding.