# Automatically detect when a trial changes its outcomes after the fact

Source: https://onco.cc/ideas/idea-tr2-outcome-switching-monitor/  
OnCo record `idea-tr2-outcome-switching-monitor` (Idea). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Trials sometimes quietly swap the outcome they promised to measure for one that looks better. Software can compare the registered plan with the published paper and flag the switch.

## Summary

The COMPare project manually compared registered and published outcomes in five top journals and found widespread undisclosed switching. Registry entries and publications are now structured enough for automated comparison, and pre-specified statistical analysis plans are increasingly public. A continuously running monitor that flags outcome discrepancies in oncology trials, notifies journals and posts findings publicly would deter switching.

## Fields

- Kind: Idea
- Last checked: 2026-09-08
- Hypothesis: Public flagging reduces undisclosed primary outcome switching in oncology trials from the roughly 30% documented in audits to under 10% within three years.
- Rationale: COMPare showed that journals correct when confronted with evidence. Automation makes the confrontation systematic rather than sporadic.
- Proposed test: Build the monitor over ClinicalTrials.gov and PubMed; audit its precision manually on 200 trials; publish quarterly reports and measure the switching rate.
- Maturity: early-clinical
- Actor: data

## Sources

- COMPare trials project: https://compare-trials.org/

## Connected records

- collections: [ClinicalTrials.gov](https://onco.cc/collections/clinicaltrials-gov/), [PubMed & Europe PMC](https://onco.cc/collections/pubmed-europepmc/)
- ideas: [Run automated statistics and image checks on every cancer manuscript before review](https://onco.cc/ideas/idea-tr2-automated-stats-check/)
- bottlenecks: [Failures are hidden](https://onco.cc/bottlenecks/b-negative-results/), [Trial design, endpoints and cost](https://onco.cc/bottlenecks/b-trial-design/)

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