How to use it
FIB-4 is the first step in checking adults with MASLD (or risk factors for it) for advanced fibrosis (F3–F4). Enter age, AST, ALT and platelets from the same day. If you already have a FibroScan (transient elastography) or ELF result, enter it too: the second test decides the next step. CAP is shown for information but does not change it.
The metabolic risk question is optional. It only sets the repeat interval when the risk is low. If you leave it blank, both intervals are shown.
Reading the result
| FIB-4 | Risk of advanced fibrosis | Next step |
|---|---|---|
| Below 1.3 (below 2.0 at age 65 or over) | Low | Primary care. Repeat every 1–2 years with prediabetes, type 2 diabetes or 2 or more metabolic risk factors, otherwise every 2–3 years |
| 1.3 to 2.67 | Indeterminate | Transient elastography or ELF. Refer if neither is available |
| Above 2.67 | High | Refer to gastroenterology or hepatology |
| Second test | Result | Next step |
|---|---|---|
| Liver stiffness (VCTE) | Below 8 kPa | Low risk: primary care, repeat FIB-4 as above |
| 8–12 kPa | Intermediate: refer | |
| Above 12 kPa | Advanced fibrosis likely: refer | |
| 20 kPa or more | Cirrhosis likely: refer; EASL advises endoscopy for varices (also if platelets are below 150) | |
| ELF | Below 7.7 / 7.7 to below 9.8 / 9.8 or more | Low / intermediate (refer) / high (refer) |
| CAP | Below 248 / 248–287 / 288 dB/m or more | Steatosis unlikely / possible / likely |
The score is shown to 2 decimals and classified on that shown value, so 1.30 is indeterminate and 2.67 is still indeterminate. Patients can read about MASLD and these tests in the fatty liver guide.
Where guidelines differ
- Repeat interval when low risk. AASLD 2023: every 2–3 years, or every 1–2 years with prediabetes, type 2 diabetes or 2 or more metabolic risk factors. EASL 2024 and the Canadian Association of Radiologists (CAR 2025): every 1–3 years. Diabetes Canada 2025: every 1–2 years in diabetes. The tool follows AASLD, which agrees with Diabetes Canada for people with diabetes.
- When to refer on liver stiffness. AASLD 2023 and CAR 2025 call 8–12 kPa intermediate; EASL 2024 and Diabetes Canada 2025 refer everyone at 8 kPa or more. Either way, 8 kPa or more leads to referral (CAR says referral “may be appropriate” at 8–12).
- FIB-4 above 2.67. EASL, Diabetes Canada and CAR refer directly. AASLD says “consider referral” and still lists a second test. If a second test is low risk but FIB-4 is above 2.67, the tool calls it discordant and still suggests referral or discussion.
- Age 65. McPherson derived the 2.0 cut-off in people aged 65 or over; AASLD and EASL write “over 65”. The tool uses 65 or over.
- ELF. Diabetes Canada refers at 7.7 or more; AASLD calls 7.7–9.8 intermediate and also refers.
- CAP. AASLD uses 288 dB/m for likely steatosis; EASL quotes the Karlas thresholds (248 for any steatosis). CAP has limited accuracy for quantifying fat.
Pitfalls
- Age. FIB-4 is unreliable at 35 or younger (consider elastography if there are metabolic risk factors or raised enzymes) and is not validated under 18. It rises with age, which is why the low cut-off is 2.0 at 65 or over.
- When FIB-4 does not apply. Acute illness or acute liver injury (a high AST inflates FIB-4), thrombocytopenia from another cause, active alcohol use and chronic kidney disease can all give a falsely high or low score (CAR 2025; AASLD 2023). The MASLD cut-offs were not built for other liver diseases.
- A low FIB-4 does not rule out fibrosis in everyone. It misses some people with advanced fibrosis, particularly those with type 2 diabetes. EASL 2024 notes that FIB-4 will miss about 10% of people with advanced fibrosis.
- Known cirrhosis. FIB-4 is for finding fibrosis, not for staging known cirrhosis. Use MELD 3.0 and Child-Pugh.