Building on sand (again)
It lookd to me like the two studies Peter White cites in his editorial and are either very or substantially flawed - which makes his intepretation of them rather irrelevant. There were 2 studies [quotes from Peter White's editorial]:
Study 1: Clustering of FSS
They recruited a sample of 368 members of “functional somatic syndrome patients' websites”, and asked them to fill in a questionnaire by the internet to elicit the presence of 47 somatic symptoms within the previous two weeks...
The samples were not clinically derived and we are not told how the patient websites were selected or what FSS they concerned. The data were all self-reported, so we cannot be sure that the patients did in fact have an FSS, since no clinical assessment was made. This was reinforced by the striking finding that 62% of the sample reported not having a current FSS at all.
So, they recrutied a bunch of people online and relied solely on self-report: most reported they didn't have a current FSS... "
GAME OVER".
But, while I'm here: why didn't they also ask participants if they also had
physical illnesses? Perhaps said FSS are actually misdiagnosed physical illnesses, and there may be a correlation with other physical illnesses. Such a question would, at least, provide some kind of reference point for the levels of additional FSS.
Study 2: Retrospective study of previous FSS in women with Interstitial Cystisis
.. a one year retrospective case control study of 312 women with a specific FSS, interstitial cystitis (irritable or painful bladder syndrome) (IC), matched by age, sex and locality with the same number of women without this condition recruited by random telephone calling
[18]. They asked all subjects to recall whether their doctor had diagnosed any one of seven FSS in the year before they developed IC.
...One might argue with the inclusion of migraine, sicca syndrome and panic disorder as FSS,
This looks like a more substantial study, though again looked only at other presumed FSS and not at any correlation with other physical illnesses. From our prespective, it says nothing about CFS either.
Studies not done
Surely, when dealing with something as vague and ill-defined as FSS, what's needed are detailed studies trying to understand what is going on in any specific FSS, teasing out any sub-groups?
Many, many physical illnesses have a broad range of symptoms (eg pain, fatigue, concentration problems)- which is precisely why CFS is so hard to diagnose - as are many chronic illnesses.
Relying on questionnaires to look for similarities between presumed FSS, with little or no medical examination to verify the details strikes me as looking at the problem from the wrong end of the telescope. Contrast this with Ian Lipkin's approach of painstakingly assembling a large and carefully defined group of CFS patients and matched controls, then looking in detail at the pathophysiology. He might draw a blank, but from such robust work it will probably be possible to draw some robust conclusions. Which is a very different scenario to this kind of rather meaningless speculation about FSS.