For healthcare professionals
Mayo PBC risk score calculator
The Mayo risk score estimates the outlook in primary biliary cholangitis from age, bilirubin, albumin, prothrombin time and edema, without a liver biopsy. Dickson and colleagues published it in 1989. This calculator is written for clinicians and is not a diagnosis.
Patient values
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What you will see
The Mayo risk score, how each value adds to it, and how it compares with 7.8.
Educational only, not medical advice. Not a diagnosis. Treatment decisions belong to the treating team.
Source
Dickson ER and colleagues, Hepatology 1989. The formula and the edema coding are taken from an open-access (CC BY) paper by Lv and colleagues, Frontiers in Immunology 2021, and match the formula in Mijic and colleagues, Canadian Journal of Gastroenterology and Hepatology 2022 (CC BY), which also gives the 7.8 threshold. The tests check the formula, the edema term, the 7.8 threshold and the unit conversions.
Validated in
Built in 1989 from 418 patients with primary biliary cholangitis in the USA, before ursodeoxycholic acid was in use (Mijic 2022).
Limits
The score was developed in untreated patients, and later models built in the ursodeoxycholic acid era focus on response to treatment. This page gives the score only, not a survival estimate. Unit conversions on this page are arithmetic and are not part of the published score.
Formula
R = 0.871 x ln(bilirubin in mg/dL) - 2.53 x ln(albumin in g/dL) + 0.039 x age in years + 2.38 x ln(prothrombin time in seconds) + 0.859 x edema (Lv 2021). The original paper is by Dickson and colleagues (Dickson 1989).
Worked example: age 50, bilirubin 1 mg/dL, albumin 4 g/dL, prothrombin time 10 seconds and no edema give 1.950 + 0 - 3.507 + 5.480 + 0 = 3.92.
For laboratory values in SI units, 1 mg/dL of bilirubin is 17.1 umol/L (Makino 2026), and albumin in g/L is divided by 10 to give g/dL.
Edema term
| Finding | Value |
|---|---|
| No edema, no diuretic therapy | 0 |
| Edema with no diuretic therapy, or no edema with diuretic therapy | 0.5 |
| Edema and diuretic therapy | 1 |
Source: Lv and colleagues 2021 (Lv 2021).
Where it is used
Dickson and colleagues proposed the Mayo score in 1989 because earlier PBC models could not accurately calculate survival and needed a liver biopsy. The Mayo score does not need liver histology, which is one reason it is still widely used (Mijic 2022).
For timing of liver transplantation in primary biliary cholangitis, the same review names an expected survival under one year (MELD 15 or higher) and, as another option, a Mayo risk score of 7.8 or higher (Mijic 2022).
Related calculators
For end-stage liver disease and transplant listing, use the MELD score calculator. To grade cirrhosis with ascites and encephalopathy, see the Child-Pugh score calculator, and for a grade from albumin and bilirubin alone, the ALBI score calculator. Other bedside scores are listed under For healthcare professionals.
Sources
- Lv L, Jiang H, Chen X, et al. The salivary microbiota of patients with primary biliary cholangitis is distinctive and pathogenic. Front Immunol. 2021;12:713647. doi:10.3389/fimmu.2021.713647. PMID 34367180. Open access (CC BY). Methods: Mayo risk score equation and edema coding. pmc.ncbi.nlm.nih.gov/articles/PMC8335641/
- Mijic M, Saric I, Delija B, et al. Pretransplant evaluation and liver transplantation outcome in PBC patients. Can J Gastroenterol Hepatol. 2022;2022:7831165. doi:10.1155/2022/7831165. PMID 35910038. Open access (CC BY 4.0). Review: Mayo score equation, 1989 USA cohort of 418, no histology needed, Mayo risk score of 7.8 or higher as an option for liver transplantation. pmc.ncbi.nlm.nih.gov/articles/PMC9337972/
- Makino T, Izumi K, Nakagawa R, et al. Prognostic value of a novel risk score combining psoas muscle density and ALBI grade in localized renal cell carcinoma. Med Sci (Basel). 2026;14(5):509. doi:10.3390/medsci14050509. PMID 42783382. Open access (CC BY 4.0). ALBI formula, bilirubin 1 mg/dL = 17.1 umol/L, origin in hepatocellular carcinoma. pmc.ncbi.nlm.nih.gov/articles/PMC13609120/
- Dickson ER, Grambsch PM, Fleming TR, Fisher LD, Langworthy A. Prognosis in primary biliary cirrhosis: model for decision making. Hepatology. 1989;10(1):1-7. doi:10.1002/hep.1840100102. PMID 2737595. Original paper (cited; the formula used here is taken from Lv 2021, CC BY). doi.org/10.1002/hep.1840100102
Written and maintained by the uncovermyrisk.com editorial team. We do not have a medical reviewer; every claim links to its primary source above. Last reviewed: 2026-11-01. Spotted an error? See About.