Leonard wrote:[...] Therefore, it is likely -in fact it is what you would expect- that people will be found with CCSVI (I guess mostly young people) that have not yet developed MS.
The prevalence of MS in the US population is about 0,13% (400.000 MSp/307 mill.).
According to a buffalo press release, the CTEVD/CCSVI study "will involve 1,600 adults and 100 children. The cohort will be comprised of 1,100 patients who were diagnosed with possible or definite MS, 300 age-and-sex matched normal controls, and 300 patients with other autoimmune and neurodegenerative diseases."
This means that even if the controls were randomly chosen (wich is not the case) and assuming that CCSVI is present in all MS patients and in no controls, the probability of finding no one with CCSVI in the control group of 600 people is about 45,8%.
If the probability of MS in the healthy group and in the patients with other diseases is about 10% of the probability of the general population (i.e. 0,013%), then the probability of finding no one with CCSVI in the control group is about 92,5%.
Concluding if our hypothesis about CCSVI holds true and due to the study design, it is not expected to find CCSVI in the control group.
Of course finding 1 or 2 individuals with CCSVI in the control group is not necessarily enough to reject the CCSVI hypothesis as it could be the case of people having not developed MS yet