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116 calculators match

Most used

21
MELD-NaAssesses the severity of chronic liver diseaseChild-Pugh ScoreAssesses the prognosis of chronic liver disease, mainly cirrhosisFIB-4 IndexLiver fibrosis scoring indexAPRIAST to platelet ratio — liver fibrosisMaddrey's DFAlcoholic hepatitis severityGlasgow-BlatchfordUpper GI bleed risk stratificationGAHSGlasgow alcoholic hepatitis scoreMontreal IBDIBD classification — CD & UCMayo ScoreUlcerative colitis activityBISAP ScoreBedside index for severity of pancreatitisCLIF-SOFAOrgan failure scoring in cirrhosisAlcohol ContentStandard drinks & alcohol grams calculatorAARC-ACLFAcute-on-chronic liver failure gradePELD / CR ScorePediatric end-stage liver diseaseHarvey-BradshawCrohn's disease activity indexCTSICT severity index — pancreatitisRockall ScoreGI bleed rebleeding & mortality riskCAGEAlcohol use disorder screening (4 questions)MELD 3.0Updated MELD — sex-inclusive formulaAUDIT ScoreAlcohol use disorders identification testVOCAL-Penn ScorePost-operative mortality risk in cirrhosis surgery

Liver & Cirrhosis

17
ALBI GradeAlbumin-bilirubin liver function grade in HCCUKELD ScoreUK model for end-stage liver diseaseMELD-XIMELD excluding INR — for anticoagulated patientsWest Haven CriteriaHepatic encephalopathy gradingMilan CriteriaLiver transplant eligibility in hepatocellular carcinomaLI-RADS v2018 (CT/MRI)Liver observation category from size, APHE and major featuresBCLC StagingHepatocellular carcinoma stage and treatment allocationSimplified AIH CriteriaSimplified criteria for autoimmune hepatitisRevised Original AIH ScoreIAIHG 1999 comprehensive autoimmune hepatitis scoreSAAGSerum-ascites albumin gradient — cause of ascitesR FactorHepatocellular vs cholestatic pattern in liver injuryCLIF-C ACLFMortality prediction in acute-on-chronic liver failureKing's College CriteriaTransplant criteria in acute liver failureGALAD ScoreHCC detection from gender, age, AFP-L3, AFP and DCPMetroticket 2.0AFP-adjusted up-to-seven for HCC transplant eligibilityRUCAMCausality in drug- and herb-induced liver injuryBaveno VII CriteriacACLD, CSPH and sparing screening endoscopy

Fibrosis & MASLD

8
NAFLD Fibrosis ScoreAdvanced fibrosis probability in MASLD/NAFLDBARD ScoreBMI, AST/ALT ratio, diabetes — MASLD fibrosisFatty Liver IndexPredicts hepatic steatosis from routine labsFibrotic NASH Index (FNI)At-risk NASH probability from AST, HbA1c and HDLNAFLD Activity Score (NAS)Histologic activity grade — steatosis, inflammation, ballooningMEFIB IndexMRE + FIB-4 rule for significant fibrosis (≥F2) in MASLDFAST ScoreFibroScan-AST — at-risk NASH from LSM, CAP and ASTSAFE ScoreSteatosis-Associated Fibrosis Estimator for MASLD in primary care

Pancreas & Biliary

8
Ranson's CriteriaAcute pancreatitis severity at 48 hoursGlasgow-Imrie CriteriaAcute pancreatitis severity — the PANCREAS criteriaHAPSHarmless acute pancreatitis scoreTokyo Guidelines — CholangitisTG18 diagnosis and severity grade for acute cholangitisTokyo Guidelines — CholecystitisTG18 diagnosis and severity grade for acute cholecystitisBiliary Pain (Rome IV)Rome IV — defining biliary-type pain before interventionFunctional Pancreatic SODRome IV — pancreatic sphincter of Oddi disorderRevised Atlanta ClassificationAcute pancreatitis severity — mild, moderately severe, severe

IBD

9
Truelove & Witts CriteriaAcute severe ulcerative colitis — admission decisionUCEISUlcerative colitis endoscopic index of severitySCCAISimple clinical colitis activity index — symptoms onlyCDAICrohn's disease activity index — the trial standardSES-CDEndoscopic severity in Crohn's diseasePUCAIPaediatric ulcerative colitis activity indexTravis (Oxford) CriteriaDay 3 colectomy risk in acute severe ulcerative colitisHo IndexDay 3 steroid failure risk in acute severe ulcerative colitisRutgeerts ScorePostoperative Crohn's recurrence at ileocolonoscopy

GI Bleeding

7
EVendo ScorePredicts oesophageal varices needing treatmentForrest ClassificationPeptic ulcer bleeding — rebleeding risk at endoscopyAIMS65 ScoreUpper GI bleed mortality — five bedside criteriaOakland ScoreSafe-discharge risk for acute lower GI bleedingABC ScoreAge, blood tests, comorbidities — GI bleed mortalitySarin ClassificationEndoscopic classification of gastric varicesEGUS (Gastric Ulcer)Malignancy risk in a gastric ulcer, and who needs repeat endoscopy

Alcohol

2
ABIC ScoreAge, bilirubin, INR, creatinine — alcoholic hepatitisLille ModelSteroid response at day 7 in alcoholic hepatitis

Upper GI

4
Chicago Classification v4.0Oesophageal motility pattern from high-resolution manometryLA Classification (Oesophagitis)Los Angeles grade A–D for erosive oesophagitisPrague C & M CriteriaCircumferential and maximal extent of Barrett's oesophagusEREFS (Eosinophilic Oesophagitis)Endoscopic reference score — oedema, rings, exudates, furrows, stricture

Colorectal

3
Boston Bowel Prep ScaleColonoscopy preparation adequacy by segmentStool Osmotic GapOsmotic vs secretory diarrhoea from stool electrolytesATLAS Score (C. difficile)Predicted response to therapy in Clostridioides difficile infection

Functional GI

37
Bristol Stool ScaleStool form types 1–7 and colonic transitRome IV Criteria for IBSIrritable bowel syndrome diagnosis and subtypeFunctional ConstipationRome IV — two of six items, IBS excludedOpioid-Induced ConstipationRome IV — constipation tied to opioid therapyFunctional DiarrhoeaRome IV — loose stools without predominant painFunctional Bloating / DistensionRome IV — bloating without other bowel disorder criteriaUnspecified Functional Bowel DisorderRome IV — bowel symptoms fitting no other categoryCentrally Mediated Abdominal Pain (CAPS)Rome IV — continuous pain unrelated to gut eventsNarcotic Bowel SyndromeRome IV — opioid-induced hyperalgesia of the gutFaecal Incontinence (Rome IV)Rome IV — the criteria, and why nobody is askedFunctional Anorectal PainLevator ani, unspecified pain and proctalgia fugaxFunctional Defecation DisordersRome IV — dyssynergia and inadequate propulsionInfant RegurgitationRome IV — the happy spitter, and the alarm features that rule it outInfant ColicRome IV — recurrent unexplained crying in a well infant under 5 monthsInfant DyscheziaRome IV — straining before a soft stool, and why not to intervenePaediatric Functional ConstipationRome IV — two of six over one month, with overflow soiling as a criterionToddler's DiarrhoeaRome IV functional diarrhoea of childhood — painless, thriving childPaediatric Cyclic Vomiting SyndromeRome IV — both age bands, with different criteria for eachPaediatric Rumination SyndromeRome IV — infant and child/adolescent criteriaFunctional Nausea & Vomiting (Children)Rome IV — two separate disorders that can be met togetherAerophagiaRome IV — distension that increases through the dayPaediatric Functional DyspepsiaRome IV — four times a month, with PDS and EPS subtypingPaediatric Irritable Bowel SyndromeRome IV — plus the constipation clause clinicians missAbdominal MigraineRome IV — stereotypical incapacitating episodes weeks apartFunctional Abdominal Pain — NOSRome IV — the residual category, reached after the other threeNonretentive Faecal IncontinenceRome IV — soiling without retention, where laxatives make it worseFunctional DyspepsiaRome IV — with PDS and EPS subtypingRumination SyndromeRome IV — effortless regurgitation without retchingCyclic Vomiting SyndromeRome IV — stereotypical episodic vomitingCannabinoid HyperemesisRome IV — CVS pattern relieved by cannabis cessationChronic Nausea & VomitingRome IV — chronic nausea and vomiting syndromeBelching DisordersRome IV — supragastric vs gastric belchingFunctional HeartburnRome IV — heartburn with normal acid exposureReflux HypersensitivityRome IV — normal acid exposure, positive symptom associationFunctional Chest PainRome IV — non-cardiac, non-reflux chest painGlobusRome IV — painless lump-in-throat sensationFunctional DysphagiaRome IV — dysphagia with normal endoscopy and manometry
  1. Calculators
  2. /
  3. FAST Score
Fibrosis & MASLD

FAST Score

FibroScan-AST — at-risk NASH from LSM, CAP and AST

Liver stiffness measurement by vibration-controlled transient elastography (FibroScan).

Controlled attenuation parameter from the same FibroScan examination.

Serum aspartate aminotransferase.

Combines two readings from a single FibroScan (liver stiffness and CAP) with serum AST. Enter LSM and CAP from the same VCTE examination.

When to use
Use it in a patient with metabolic (MASLD/NAFLD) liver disease who is having, or can have, a FibroScan, when the question is whether they have the active, fibrotic form of the disease worth treating rather than simple steatosis. It is well suited to a hepatology or specialist metabolic clinic where FibroScan is on hand, as a one-stop test that turns a stiffness reading, a CAP and an AST into a single actionable probability. It is not a first-line population screen — it needs the machine — it does not stage fibrosis precisely, and it is validated in metabolic liver disease rather than in viral or alcohol-related disease.
Why use it
Because the phenotype that treatment and trials target — at-risk NASH — is defined by activity and fibrosis together, and most non-invasive tools measure only one of them. FIB-4 and the NAFLD Fibrosis Score estimate fibrosis; CAP alone estimates fat; neither tells you whether inflammatory activity and fibrosis coexist. FAST was derived directly against the composite at-risk-NASH endpoint using data a FibroScan visit already produces, so it identifies, at the point of care and without a biopsy, the patients in whom that combination is present. In its global validation it excluded at-risk NASH with a negative predictive value of 0.94, which is the argument for it: a cheap, same-visit way to stand down most of the people who do not need a biopsy.
Formula, evidence and interpretation

About the FAST Score (FibroScan-AST)

The FAST (FibroScan-AST) score combines two readings from a single FibroScan — liver stiffness (LSM) and the controlled attenuation parameter (CAP) — with serum AST to estimate the probability of at-risk (fibrotic) NASH: steatohepatitis with a NAFLD activity score of at least 4 and fibrosis of at least F2. It returns a value from 0 to 1. At or below 0.35 at-risk NASH is effectively ruled out (sensitivity 0.90; negative predictive value up to 0.94 on external validation); at or above 0.67 it is ruled in (specificity 0.90); the 0.35–0.67 grey zone needs further assessment. FAST captures both fibrosis (through stiffness) and activity (through CAP and AST) in one visit, which is what a fibrosis-only score such as FIB-4 cannot do.

On this page

  • Formula
  • Interpreting the result
  • Inputs
  • What it returns
  • How it is calculated
  • Facts & figures
  • Evidence
  • How it compares
  • Pearls & pitfalls
  • Critical actions
  • Why it exists
  • About the creator
  • Limitations
  • If you are the patient
  • FAQ
  • Related calculators
  • References

Formula

FAST = eˣ / (1 + eˣ), where x = −1.65 + 1.07·ln(LSM) + 2.66×10⁻⁸·CAP³ − 63.3·AST⁻¹
LSM
Liver stiffness in kPa. Natural log, coefficient 1.07.
CAP
Controlled attenuation parameter in dB/m. Enters cubed, coefficient 2.66×10⁻⁸.
AST
U/L. Enters as its reciprocal (1/AST), coefficient −63.3.
  • LSM is in kPa, CAP in dB/m and AST in U/L — the coefficients are calibrated to those units and no conversion is applicable.
  • CAP enters as a cube, so a modest change in CAP produces a larger change in the score than its small coefficient suggests; reliable CAP acquisition matters.
  • AST enters as a reciprocal, so the score is most sensitive to AST at low values and flattens as AST rises.
  • A published correction to the original paper affected only the Table 2 column labels (specificity/sensitivity for the rule-in zone); the formula itself was unchanged.

Interpreting the result

Read FAST as a triage probability with three exits. At or below 0.35 the negative predictive value is high — 0.85 in the derivation cohort and 0.94 in external validation — so at-risk NASH can be excluded and the patient managed for metabolic risk with reassessment over time. At or above 0.67 the specificity is 0.90, and the patient should move toward specialist assessment, consideration of treatment or a trial, and definitive staging where needed. Between 0.35 and 0.67 — where roughly a third of patients land — the score is uninformative and a further test is required; treating that grey zone as negative is the characteristic error. Because the rule-in positive predictive value is well below certainty, a high FAST identifies whom to investigate, not a diagnosis.

ScoreBandWhat it meansAction
≤ 0.35Rule-out zoneAt-risk NASH unlikely — sensitivity 0.90; NPV 0.85 (derivation), 0.94 (validation)Manage metabolic risk factors; reassess over time. No immediate biopsy
0.35–0.67IndeterminateGrey zone — around a third of patients. FAST neither excludes nor confirms at-risk NASHProceed to a further test (MRI-based assessment, or biopsy where it changes management)
≥ 0.67Rule-in zoneAt-risk NASH likely — specificity 0.90; PPV 0.83 (derivation)Specialist referral; consider treatment or trial assessment and definitive staging

What the FAST Score needs (3 inputs)

Liver stiffness / LSM (kPa)
Liver stiffness by vibration-controlled transient elastography (FibroScan). It enters as a natural logarithm and is the fibrosis component of the score. LSM is confounded by obesity, ascites, food intake and acute hepatitis.
CAP (dB/m)
The controlled attenuation parameter from the same FibroScan examination, a measure of hepatic fat. It enters as a cube (CAP³) with a very small coefficient, so the score is sensitive to CAP measurement quality and to the probe used.
AST (U/L)
Serum aspartate aminotransferase, entering as its reciprocal (AST⁻¹) — the activity/injury component. Any non-NASH cause of a raised AST will move the score.

What it returns

FAST score
A probability between 0 and 1 of at-risk (fibrotic) NASH. It is not a fibrosis stage and not a NAFLD activity score.
Risk zone
Rule-out (≤ 0.35), indeterminate (0.35–0.67) or rule-in (≥ 0.67). Roughly a third of patients fall in the grey zone.

How it is calculated

FAST is a logistic regression that deliberately draws one variable from each axis of at-risk NASH. Liver stiffness represents fibrosis; CAP represents steatosis; AST represents hepatocellular injury and, by proxy, inflammatory activity. Combining a fibrosis marker with two activity/fat markers lets a single score estimate the composite histological target — NASH with NAS ≥ 4 and F ≥ 2 — that neither a stiffness reading nor a blood test achieves alone. The unusual shapes of the terms (a cubed CAP, a reciprocal AST) are simply the transformations that best fitted the data in the derivation cohort; they are empirical, not mechanistic, which is why measurement quality in each component feeds directly through to the result.

Facts & figures

Diagnostic thresholds
ThresholdPurposePerformance
≤ 0.35Rule out at-risk NASHSensitivity 0.90; NPV 0.85–0.94
0.35–0.67Indeterminate≈ one-third of patients; further testing
≥ 0.67Rule in at-risk NASHSpecificity 0.90; PPV 0.83

Target is at-risk (fibrotic) NASH: histological NASH with NAS ≥ 4 and fibrosis ≥ F2.

Evidence base
SourceCohortDiscrimination
Newsome 2020 (derivation)350, UK, biopsy-provenAUROC 0.80
Newsome 2020 (global validation)1,026 across 7 cohortsAUROC 0.85
Ravaioli 2023 (meta-analysis)12 studies, 5,835 participantsPooled sensitivity and specificity 0.89

Evidence

Derivation — UK biopsy cohort

2020 · n = 350

350 patients with suspected NAFLD undergoing liver biopsy with contemporaneous FibroScan (LSM and CAP) and AST. Logistic regression against biopsy-defined at-risk NASH (NASH, NAS ≥ 4, fibrosis ≥ F2) selected LSM, CAP and AST for the FAST score.

AUROC 0.80. At ≤ 0.35, sensitivity 0.90 and NPV 0.85; at ≥ 0.67, specificity 0.90 and PPV 0.83.

Global external validation

2020 · n = 1,026

Seven independent international cohorts totalling 1,026 patients, applying the fixed 0.35 and 0.67 thresholds.

AUROC 0.85; negative predictive value 0.94 at the 0.35 rule-out threshold, confirming strong exclusion performance across populations.

Systematic review and meta-analysis

2023 · n = 5,835

Ravaioli and colleagues pooled 12 observational studies of biopsy-proven NAFLD (5,835 participants).

Pooled sensitivity and specificity both 0.89, supporting good overall performance for non-invasive identification of fibrotic NASH.

How it compares

FAST Score vs Fibrotic NASH Index (FNI)

Same target, different inputs — both estimate at-risk NASH, but FNI needs only bloods while FAST needs a FibroScan, so FNI screens broadly and FAST confirms more accurately where elastography is available.

FNI (AST, HbA1c, HDL) is a blood-only score that can be run across a whole clinic's records; FAST adds the accuracy of liver stiffness and CAP at the cost of needing the machine. A sensible pathway runs a blood-based score such as FNI or FIB-4 first, then FAST on those who remain, reserving MRI-based tests or biopsy for the FAST grey zone.

Open the Fibrotic NASH Index (FNI) calculator →

FAST Score vs FIB-4

They answer different questions — FIB-4 estimates advanced fibrosis from bloods, FAST estimates at-risk NASH from a FibroScan plus AST — so FIB-4 triages fibrosis risk cheaply and FAST characterises the active fibrotic phenotype.

FIB-4 is the guideline first-line rule-out for advanced fibrosis and needs nothing but a blood panel. FAST targets the activity-plus-fibrosis composite and requires elastography. They are complementary steps rather than competitors: FIB-4 to decide who needs elastography, FAST to characterise those who reach it.

Open the FIB-4 calculator →

FAST Score vs MEFIB index

Both use elastography, but FAST relies on the widely available FibroScan while MEFIB relies on MRE and reached a higher positive predictive value head-to-head — access versus accuracy.

In a direct comparison, MEFIB (MRE plus FIB-4) identified treatment candidates with a higher positive predictive value for significant fibrosis than FAST, reflecting MRE's superior accuracy. FAST's advantage is deployability: FibroScan is far more available and cheaper than MR elastography, so FAST is the more practical of the two where MRI capacity is limited.

Open the MEFIB index calculator →

Pearls & pitfalls

  • FAST estimates at-risk NASH, a combination of activity and fibrosis — it is not a fibrosis stage and answers a different question from FIB-4 or a stiffness reading alone.
  • CAP enters cubed, so the score is sensitive to CAP measurement quality and to the probe (M vs XL); an unreliable CAP undermines the result.
  • LSM is confounded by obesity, ascites, recent food and acute hepatitis; a spuriously high stiffness inflates the score.
  • AST enters as a reciprocal, so the score responds sharply to AST at low values — small AST differences matter more there than at high values.
  • Roughly a third of patients fall in the 0.35–0.67 grey zone, where the score is uninformative; do not read that as negative.
  • The rule-in positive predictive value is 0.83, not certainty — a high FAST is a trigger for assessment, not a diagnosis.
  • It requires a FibroScan with CAP, so it cannot be run from bloods alone the way FIB-4 or FNI can.

Critical actions

  • Use a technically adequate FibroScan — reliable LSM and CAP with an appropriate probe — before trusting the score.
  • Act on the grey zone with a further test rather than filing an indeterminate result as normal.
  • At rule-in, refer for specialist assessment and consider treatment or trial eligibility and definitive staging.
  • Check that a raised AST has a plausible hepatic explanation, since AST is one of the three inputs.
  • Treat the metabolic drivers at every score level; a low FAST does not make obesity or diabetes benign.
  • Record LSM, CAP and AST alongside the score so the result can be re-checked and reproduced.

Why this score exists

FAST was designed to answer a question FibroScan alone could not: not 'how stiff is the liver' but 'does this person have the active, fibrotic disease that treatment targets'. Its authors combined the two FibroScan outputs with AST precisely because at-risk NASH is a composite of steatosis, activity and fibrosis, and no single reading captures all three. They also fixed the two thresholds — a low one for exclusion and a high one for confirmation — accepting a wide indeterminate band in between rather than forcing a binary call, which reflects an honest view that a same-visit score should be trusted at its extremes and deferred to further testing in the middle.

About the creator

  • Philip N. Newsome

    First author, 2020 derivation study

    Led the multicentre derivation combining liver stiffness, controlled attenuation parameter and AST to identify fibrotic steatohepatitis.

  • Stephen A. Harrison

    Senior author

    Also first author of the much simpler BARD score, twelve years earlier.

Limitations

  • It requires a FibroScan with a reliable CAP, so it cannot be computed from blood tests alone and is unsuitable as a population-wide screen.
  • Liver stiffness is confounded by obesity, ascites, food intake and acute hepatitis, any of which can distort the score.
  • CAP enters cubed and is the least standardised of the inputs, making the score sensitive to CAP measurement quality and probe choice.
  • Around a third of patients fall in the indeterminate grey zone, where the score provides no answer.
  • The rule-in positive predictive value is 0.83, so a high score identifies whom to investigate rather than establishing a diagnosis.
  • It was derived and validated in metabolic (MASLD/NAFLD) liver disease and should not be transferred to viral or alcohol-related disease without dedicated evidence.

If you are the patient

The FAST score is a way of combining a liver scan with a blood test to see whether fatty liver disease has become the more serious, active and scarring type that may need treatment. It uses two numbers from a FibroScan — one for how stiff the liver is (a sign of scarring) and one for how much fat is in it — together with a liver enzyme called AST from a blood test. Added together in a formula, these give a score between 0 and 1. A low score (0.35 or under) means the serious form is unlikely, and the focus stays on healthy-lifestyle changes and managing weight, blood sugar and cholesterol. A high score (0.67 or above) means it is likely, and you would usually see a liver specialist and may need more tests. A score in between is common and means the test could not tell, so another test is needed — not bad news in itself, just a sign that more information is required. The scan needs to be done well for the number to be reliable, which is why it is usually done in a specialist clinic.

Frequently asked questions

What is the FAST score?#

The FAST (FibroScan-AST) score is a non-invasive test that combines liver stiffness (LSM) and the controlled attenuation parameter (CAP) from a FibroScan with serum AST to estimate the probability of at-risk (fibrotic) NASH — steatohepatitis with a NAFLD activity score of at least 4 and fibrosis of at least F2. It is used to identify patients with the active, fibrotic form of metabolic fatty liver disease.

What FAST score is reassuring?#

A FAST score at or below 0.35 is the rule-out result: at-risk NASH is unlikely, with a negative predictive value of 0.85 in the derivation cohort and 0.94 in external validation. There is no single 'normal' value — the score is a probability, and the reassuring band is defined by that 0.35 threshold.

What does a FAST score above 0.67 mean?#

It falls in the rule-in zone, where specificity is 0.90 — at-risk NASH is likely and specialist assessment, treatment or trial consideration, and definitive staging are warranted. It is not a diagnosis: the positive predictive value at this threshold was 0.83, so it identifies whom to investigate rather than confirming the disease outright.

How is FAST different from FIB-4?#

FIB-4 estimates advanced fibrosis (stage F3–F4) from blood values alone, whereas FAST estimates at-risk NASH — a combination of disease activity and fibrosis — and needs a FibroScan as well as AST. They answer different questions, so a patient can be low-risk on one and not the other. FIB-4 is the cheap first-line fibrosis rule-out; FAST characterises the active fibrotic phenotype.

Why does the FAST calculator need a FibroScan?#

Two of its three inputs — liver stiffness and CAP — come from a vibration-controlled transient elastography (FibroScan) examination and cannot be obtained from blood tests. That is what lets FAST capture fibrosis and fat directly, but it also means the score can only be calculated when a FibroScan has been performed, unlike blood-only scores such as FIB-4 or the Fibrotic NASH Index.

Does FAST replace a liver biopsy?#

It reduces the need for one. FAST excludes at-risk NASH cheaply at the low threshold and flags likely cases at the high threshold, so many patients avoid biopsy. Those in the 0.35–0.67 grey zone, and some at rule-in, still need further assessment — MRI-based testing or biopsy — to confirm the phenotype and stage fibrosis.

Related calculators

  • Fibrotic NASH Index (FNI) — At-risk NASH probability from AST, HbA1c and HDL
  • FIB-4 Index — Liver fibrosis scoring index
  • MEFIB Index — MRE + FIB-4 rule for significant fibrosis (≥F2) in MASLD
  • NAFLD Fibrosis Score — Advanced fibrosis probability in MASLD/NAFLD
  • NAFLD Activity Score (NAS) — Histologic activity grade — steatosis, inflammation, ballooning
  • SAFE Score — Steatosis-Associated Fibrosis Estimator for MASLD in primary care

References

Original / primary reference

  1. Newsome PN, Sasso M, Deeks JJ, et al. FibroScan-AST (FAST) score for the non-invasive identification of patients with non-alcoholic steatohepatitis with significant activity and fibrosis: a prospective derivation and global validation study. Lancet Gastroenterol Hepatol. 2020;5(4):362-373.

Validation

  1. Ravaioli F, Dajti E, Mantovani A, et al. Diagnostic accuracy of FibroScan-AST (FAST) score for the non-invasive identification of patients with fibrotic non-alcoholic steatohepatitis: a systematic review and meta-analysis. Gut. 2023;72(7):1399-1409.
  2. Tamaki N, Imajo K, Sharpton S, et al. Magnetic resonance elastography plus Fibrosis-4 versus FibroScan-aspartate aminotransferase in detection of candidates for pharmacological treatment of NASH-related fibrosis. Hepatology. 2022;75(3):661-672.

Clinical practice guidelines

  1. Berzigotti A, Tsochatzis E, Boursier J, et al. EASL Clinical Practice Guidelines on non-invasive tests for evaluation of liver disease severity and prognosis – 2021 update. J Hepatol. 2021;75(3):659-689.
  2. EASL-EASD-EASO Clinical Practice Guidelines on the management of metabolic dysfunction-associated steatotic liver disease (MASLD). J Hepatol. 2024;81(3):492-542.
  3. Rinella ME, Neuschwander-Tetri BA, Siddiqui MS, et al. AASLD Practice Guidance on the clinical assessment and management of nonalcoholic fatty liver disease. Hepatology. 2023;77(5):1797-1835.

Further reading

  1. Kleiner DE, Brunt EM, Van Natta M, et al. Design and validation of a histological scoring system for nonalcoholic fatty liver disease (NAS). Hepatology. 2005;41(6):1313-1321.
  2. Tavaglione F, De Vincentis A, Jamialahmadi O, et al. Development and Validation of a Score for Fibrotic Nonalcoholic Steatohepatitis (FNI). Clin Gastroenterol Hepatol. 2023;21(6):1523-1532.e1.

Last updated July 30, 2026. Clinical knowledge base written and curated by GastroAGI Team from primary medical literature.

Written from primary literature and not yet independently clinically reviewed.

For use by qualified healthcare professionals. This calculator supports clinical judgement and does not replace it.