# Risk score and risk percentile

Source: https://onco.cc/terms/prognosis-risk-percentile/  
OnCo record `prognosis-risk-percentile` (Term). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

A risk score is a model's estimate of how likely a bad outcome is; a risk percentile says where that estimate sits compared with a reference group of patients.

## Summary

Prognosis is a medical prediction of the likely course of a disease (Wikipedia). Prediction models turn many variables into a single score, often reported as a percentile against a reference cohort (a patient in the 90th percentile is predicted to do worse than nine in ten comparable patients) or cut into low, intermediate and high risk groups. A percentile ranks; it says nothing about absolute risk unless the model is calibrated.

## Fields

- Kind: Term
- Last checked: 2026-09-24
- Also known as: risk percentile; risk score; prognostic score; predicted risk; risk group; risk stratification
- Tags: cansim-terms

## Notes

- Listed in the CanSim terms map 1.0.0 (docs/onco/terms.json, generated 2026-09-24), CC BY 4.0, attribution: CanSim project, an open, public-data-first cancer foundation-model programme; CanSim page path /terms/prognosis-risk-percentile.

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Prognosis
- Wikipedia: https://en.wikipedia.org/wiki/Prognosis

## Connected records

- terms: [C-index (concordance index), Harrell's and Uno's](https://onco.cc/terms/concordance-index/), [Calibration: reliability diagrams and the Brier score](https://onco.cc/terms/calibration/), [Cancer AI vocabulary (CanSim terms map)](https://onco.cc/terms/cancer-ai-vocabulary/), [Prognosis](https://onco.cc/terms/prognosis/)

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JSON: https://onco.cc/api/v1/entities/prognosis-risk-percentile.json