The same thing happened for the DecodeME project. They knew there was an issue with diagnosis in the UK but they still required it as an input despite then largely ignoring it and requiring CCC assessment anyway. They did it because of the expectation of UK doctors and trying to get credibility for the findings, in the end it bit them because they couldn't recruit the 25,000 they wanted to. It didn't hurt the patient criteria or result it just impacted on the total they could recruit, so a lower impact than usual.
Some corrections and clarifications.
"they still required it as an input despite then largely ignoring it"
It was part of the process of defining our study cohort - I'd be curious to know what else you might have expected us to make of that specific bit of data?
"requiring CCC assessment"
Participants were assessed against the CCC
and IOM/NAM criteria.
"They did it because of the expectation of UK doctors and trying to get credibility for the findings"
We did it to define our study cohort in the most reasonable way we could.
"in the end it bit them because they couldn't recruit the 25,000 they wanted to"
We had over 37k people who signed up to our mailing list and just short of 27k complete the screening questionnaire, of those just over 21.5k were eligible to donate saliva, and 18k of those returning samples to us. Yes, we had a headline number of 25k participants but always anticipated losing numbers at each stage and we actually ended up broadly where we needed due to higher than anticipated retention rates.
"It didn't hurt the patient criteria or result it just impacted on the total they could recruit, so a lower impact than usual."
I don't understand the point that you are making here. We recruited enough patients who donated sufficient saliva samples in order for us to be able to run a sufficiently powered GWAS.