Chronic fatigue syndrome (CFS/ME) symptom-based phenotypes & 1-year treatment outcomes in two clinical cohorts of adult patients.., 2017, Collin et al

And those with less severe symptoms are probably more likely to subjectively self report improvement even though none actually exists.

 

Exactly..

That said, it looks like this article was written by the first three authors with less input from Crawley/Knoop...

 

Corrigendum to “Chronic Fatigue Syndrome (CFS) symptom-based phenotypes in two clinical cohorts of adult patients in the UK and The Netherlands”

The authors regret that there was an error in the Ethics Statement.

The corrected Ethics Statement as follows: The UK CFS patient data were collected as part of routine clinical practice and anonymised for the National Outcomes Database. Under the Governance Arrangements for Research Ethics Committees (September 2011), ethical review is not required for research limited to the use of previously collected, non-identifiable patient information.

The authors would like to apologise for any inconvenience caused.

https://www.sciencedirect.com/science/article/pii/S0022399923001812