The FIB-4 index-a common blood-based screening tool for liver fibrosis-shows poor accuracy in patients with metabolic dysfunction-associated steatotic liver disease (MASLD), according to a new study across Belgian and Dutch primary care clinics.
MASLD, affecting nearly one-third of the global population, can silently progress from fat accumulation to cirrhosis and liver cancer. Early detection of fibrosis stage F2 or higher is critical, yet current guidelines rely heavily on FIB-4 as a first-line screen.
FIB-4 uses age, AST, ALT, and platelet count-routine lab values-but researchers found only slight agreement between its results and liver stiffness measurements from vibration-controlled transient elastography (VCTE) in 1,285 participants.
False positives were rampant: over 81% of referrals in patients under 65 based on FIB-4 ≥1.3 were not confirmed by VCTE. False negatives also rose with age-8.8% in younger adults, 18.5% in those over 65.
Accuracy suffered most in high-risk groups like those with type 2 diabetes or obesity. Alternative age-based cut-offs offered minimal improvement.
While useful for population-level trends, FIB-4’s limitations in individual risk assessment could lead to missed diagnoses or unnecessary specialist referrals-highlighting the urgent need for better non-invasive MASLD screening tools.