"On the BDI, 32% of patients did not have depressed feelings at all."
If I interpret that correctly, they are referring to the Beck Depression Inventory.
SO.... if 32% of patients SAID they didn't have depressed feelings... that would mean that 68% of patients said they DID have depressed feelings... which makes this cohort EVEN worse (as if that were possible), no?
“A minimum of 36% of the patients had clinical depression. It is entirely possible that the figure was as high as 68%.”
…To put it bluntly if the authors of this study reported that it was a well characterised (CFS) cohort they either don’t understand the disease area at all or were being disingenuous”
In case you missed it, Gerwyn did a masterful exposee of the Dutch Cohort on this thread: http://www.forums.aboutmecfs.org/sho...ight=vercoulen . And it was based on his trailblazing that I decided to look again at the whole BMJ issue. I urge you to read Gerwyn's original piece - it's characteristically excellent.
And in response to Julius’ question about the attempt to, “Minimalize the risk of including patients with delayed convalescence of a viral infection”.
What has swayed me toward the likelihood that there are VERY few (if any) patients with viral etiology in their cohort was the fact that they said,
"Minimalize the risk of including patients with delayed convalescence of a viral infection", NOT "Minimalize the risk of including patients with convalescence of a viral infection".
And it raises the question of just WHY they were so adamant to keep out the viral cases. Again, questions need to be asked, and answers weighed in the context of the integrity of previous data.
For me the Symptom Section is the most disturbing part of the document thus far. Some of the cardinal signs of ME/CFS are not presented that significantly. While myalgia is high, only 50% had concentration problems, only 43% had sleep disturbances - that is a glaring difference! Only 13% had sore throat. Sore throat isn't as common as was first believed (altho I had one for about 10 years) but still only 13%.
This really seems to me to be a very good indication that these were not your typical CFS patients and that this cohort was not representative of us. In a sense this group was pretty well characterized but they don't appear to be CFS patients (!).
(From the article) And together, they still only (weakly) explain 28% of the variance. Which rather nicely summarizes the perspectives of many CFS researchers 16 years ago – and even today. They don't know what they're studying. Yet this reinforces the British and indeed Dutch paradigm to deny ME/CFS patients physical testing and diagnostics. Why bother when it’s all psychosomatic?!
I agree that this is a real problem. 28% should not be a convincing number; it should be a warning sign to look elsewhere!
Cohort, Cohort, Cohort - You started out with a question about the cohort - that is the key question here. Was that group representative? It sure doesn't look like it -which is an important finding I think!
Very Interesting. Examining this in detail makes you wonder how this team's earlier studies ever managed to get published.
Just one small point - and it is a small point in an otherwise excellent analysis. While the inclusion of psychological measures in the original study that provided the BMJ study cohort clearly highlights the motivations of the researchers and the underlying conceptual model, their inclusion and the analysis of these factors doesn't, in itself, necessarily strengthen the case for it not being an 'organic ME/CFS' cohort.
As you know a correlation, no matter how strong, does not necessarily mean causation, nor can one infer the 'direction' of the effect unless the study manipulates the IV. The researchers obviously hoped to demonstrate a correlation between psychological factors and the type and degree of symptoms with measures such a depression, locus of control, self efficacy etc being designated as the independent variables. However as the psychological and illness measures where taken concurrently, it would be equally legitimate to designate the measures of fatigue etc as the IV and the psychological measures as DV's. In fact it could be argued that there is greater face validity in positing that having a little understood, largely untreated and extremely disabling illness is extremely likely to have a negative impact on measures such as depression, feelings of control and self-efficacy in the expected direction.
In addition, as stated; they only found a weak correlation and had to conclude that much of the variability in the measures remained 'unexplained'.
Taken together, an equally strong case could be made that these people were in fact a 'well defined' cohort and that the study had failed because the factors driving the degree of illness were organic rather than psychological.
Not that I believe they were a well defined cohort, the other points made are more than suggestive that they were not. I just don't think this particular argument is the strongest.
The 5-part Article: Scandal in BMJ’s XMRV/CFS research
For those of you joining this thread as “virgins”, check jump to the beginning to read the 5-part article, specifically posts #1, 2, 4, 6, 7 , starting here http://www.forums.aboutmecfs.org/sho...V-CFS-Research.
If you can add any email addresses and/or names to the list from post #88, please do! (sorry - technical problems - I can't seem to copy it below for now, but here's the link again: http://www.forums.aboutmecfs.org/sho...Research/page9 ). Other ideas for who we should contact to try to get this article retracted and/or to publicize the BBC's and van Kuppeveld et al's glaring flaws in cohort selection? Any more ideas on someone (or an organization) which might sponsor a formal complaint to the UK Press Complaints Commission (I have pretty much the writing done – all they need to do is submit it) and/or directly to Fiona Godlee, the BMJ Editor-in-Chief?
Update of contact and to-do lists coming
I'll work on an update of our contact list (and how to post it). If no one else does a summary by Monday, then I'll take a kick at it (but takers MOST welcome to do it!)
What we REALLY need is a champion or sponsor to take our package of letter/complaint/article/summary to the next level. And of course more media proliferation...Ideas...?
Charityfundraiser, you're absolutely that "well characterized" doesn't automatically mean that the cohort is comparable. However the BMJ explicitly called their cohort a "well defined" cohort of CFS patients. Which it wasn't. They misrepresented their cohort. Plain and simple. Which added smoke and mirrors to the issue of whether they could in fact make these grandiose statements - something to the effect that XMRV is "unlikely to be related to ME/CFS". One good thing - van Kuppeveld said he'd be pulling out of XMRV research!
Marco, your points are excellent. I think the key is though that the Vercoulen et al team DID specify the psychological variables primarily as the independent ones, and fatigue severity as the ultimate dependent one. More importantly when you map it out, and follow through from independent to dependent variables, and ultimately to fatigue severity, you see the directionality of their model that they themselves posited- which certainly fits with the hypotheses they have made all along that ME/CFS is psychogenic. What is important here (I think) is that by their own admission the directionality (even though as you say the measures were measured concurrently) was psycogenic cause of fatigue... Plus of course the fact that they intentionally "minimalized the risk of including patients with delayed convalescence of a viral infection". And all that other good stuff.
Bottom line, they used a cohort that was by their own admission a group of depressed patients with unexplained fatigue - who had been explicitly screened to remove patients with, "delayed convalescence of a viral infection".
One other consideration... Look look at the math. In Leonard Jason's work (I think it was his at least?) on how jumping from Canadian to CDC criteria there can be a ten-fold increase in sheer numbers of patients. In other words, true ME/CFS occupies only "about" 10% of the population of the more looseley defined CFS criteria. I suspect in Oxford it is quite conceivable to have even less than 10% true ME patients. Now, given that the Vercoulen sample started out at approximately 400, and ended up at approximately 300... AND the fact that they explicitly screened out viral patients etc... The reality arises that they may well have screened out ALL ME patients AND THEN SOME - i.e. patients with other organic but as-yet-undiagnosed causes of fatigue. The numbers certainly support it.
Bottom line, I agree with your point Marco - and your conclusion - they need to go back to elementary school to learn how to establish a "well-defined cohort" of ME/CFS patients.
As you know, your work has been picked up and spread around the Internet for all to read. Great job and very impressive.
My question: Have you sent this off to BMJ for any sort of review or comment? If so, have they bothered to respond?
Because you have caught the study (Van Kuppeveld et al’s BMJ XMRV work) with their "pants down", IF you get any sort of feedback from BMJ or the VK authors, expect extreme hostility and that typical pompous attitude. THEY now know that WE know they messed up big time - thanks to you and other brilliant CFIDS/ME folks.
Hey Parvo greet job. Is there any chance you can get this published in a Scientific Journal? You might need to compact it to only focus on the "well-characterized" part but it is such a blistering critique.