NAFLD Fibrosis Score Calculator

The calculator utilizes a clinically validated regression equation that weighs multiple metabolic and biochemical parameters. First, it computes your Body Mass Index (BMI) using weight and height, and establishes the AST to ALT ratio. It then applies these derived metrics alongside age, hyperglycemia status (diabetes), platelet count, and serum albumin levels into the core formula: Score = (-1.675) + (0.037 * Age) + (0.094 * BMI) + (1.13 * Diabetes) + (0.99 * AST/ALT Ratio) - (0.013 * Platelet Count) - (0.66 * Albumin). The resulting score categorizes patients into low, indeterminate, or high risk for advanced fibrosis.

Consider a 52-year-old patient with a BMI of 31.0 kg/m2, who has Type 2 diabetes. Their laboratory panel shows an AST of 45 U/L, an ALT of 30 U/L (yielding an AST/ALT ratio of 1.5), a platelet count of 190 x 10^9/L, and a serum albumin level of 4.0 g/dL. Substituting these variables into the equation yields: Score = (-1.675) + (0.037 * 52) + (0.094 * 31.0) + (1.13 * 1) + (0.99 * 1.5) - (0.013 * 190) - (0.66 * 4.0). Calculating each component results in: -1.675 + 1.924 + 2.914 + 1.13 + 1.485 - 2.47 - 2.64 = 0.668. Because this final score exceeds the high-risk threshold of 0.675 (or falls into the indeterminate/high zone depending on precise cutoff adaptations), the clinician would recommend further diagnostic evaluation such as elastography.

Ensure that all laboratory values—especially AST, ALT, albumin, and platelet counts—are derived from recent blood draws processed by a certified diagnostic lab. When calculating your BMI, double-check your height and weight measurements to avoid skewing the metabolic component of the formula. Remember that this score is a screening aid rather than a definitive diagnosis, and any concerning results should be reviewed thoroughly with a hepatologist or primary care physician.