# Simulate eligibility against real-world data before every protocol is locked

Source: https://onco.cc/ideas/idea-tr1-eligibility-impact-statement/  
OnCo record `idea-tr1-eligibility-impact-statement` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Before a trial is finalised, run its entry rules against records of real patients with that cancer and report what fraction would qualify. If it is under half, explain why.

## Summary

An 'eligibility impact statement' in the protocol: the criteria are applied to a de-identified real-world cohort (EHR-derived or registry) and the eligible fraction, its demographic profile and the criteria excluding the most patients are reported. Work using real-world oncology data has shown that relaxing common criteria roughly doubles the eligible population with little change in estimated treatment effect.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Protocols with a pre-lock eligibility impact statement will end up with a higher real-world eligible fraction and faster accrual than protocols without one, because the statement makes the cost of each criterion visible to the team writing it.
- Rationale: Teams over-restrict because restriction feels safe and its cost is invisible. A number on the page changes the conversation; this is how carbon and cost-impact statements work in other fields.
- Proposed test: A sponsor introduces the statement for half of its new protocols by random allocation of programmes and compares eligible fraction and accrual speed after 18 months.
- Maturity: early-clinical
- Actor: industry

## Sources

- Evaluating eligibility criteria of oncology trials using real-world data and AI (Nature 2021): https://www.nature.com/articles/s41586-021-03430-5

## Connected records

- technologies: [AI trial matching & clinical decision support](https://onco.cc/technologies/ai-trial-matching/)
- terms: [Real-world evidence](https://onco.cc/terms/real-world-evidence/)
- bottlenecks: [Trials enrol too few, too slowly](https://onco.cc/bottlenecks/b-trial-enrolment/), [Weak real-world evidence and registries](https://onco.cc/bottlenecks/b-real-world-evidence/)
- roadmaps: [Trial modernisation roadmap: the randomised trial → platforms and adaptive designs → decentralised, pragmatic and always-on](https://onco.cc/roadmaps/trial-modernisation-roadmap/)

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