We are 11 months into a research project led by Professor Leonard Jason from DePaul University, in Chicago.
The project aims to understand the barriers to developing an agreed upon research case definition, identify which symptoms are essential for a definition, and explore how consensus might be achieved.
Reaching agreement on how ME/CFS is defined and measured is crucial for improving diagnosis, research quality, and ultimately patient care. It could enable, for example, independent studies to be more easily compared.
The team are busy analysing the data generated by the 2025 international survey which was completed by more than 4,000 people (with ME/CFS, caregivers, clinicians, researchers, and advocates).
Given the scale of the dataset and the importance of ensuring robust analysis, the ME Association has agreed that additional time will strengthen the final output and maximise the impact of the work.
Therefore, a 12-month no cost extension has been formally approved. This will allow the research team the time they need to publish the scoping review and prepare the survey data and its qualitative content for publication.
Progress so far
The project aims to strengthen how ME/CFS is defined in research by drawing on community feedback and reviewing existing severity measures. To date, the team has completed three pieces of work:
- A scoping review of illness severity measures, which has been submitted for publication and is currently under peer review.
- A workshop at the 2025 IACFS/ME International Conference
- A poster presentation of preliminary survey findings at the 2025 Annual Midwest Ecological Conference in Chicago, titled ‘Can We Reach Consensus on a Research Case Definition for ME/CFS?’
These outputs reflect steady progress and demonstrate the value of the project for improving standards in the field of ME/CFS research.
More information
- The MEA Ramsay Research Fund | Current Projects | Can We Reach Consensus on ME/CFS Research Criteria?
- 22 May 2026 | Update: Can We Reach Consensus on ME/CFS Research Criteria?
- 09 October 2025 | Research Update: ME Research Case Definition Consensus Survey
- 12 September 2025 | New Study to Harmonise Research Definitions in ME/CFS