MAGICAL MEDICINE: HOW TO MAKE AN ILLNESS ... - Invest in ME

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To many people, it is incomprehensible how such a method of assessment could be deemed scientific when
assessing those with ME/CFS, but the MRC Data Monitoring and Ethics Committee apparently had no
problem agreeing to its use as an outcome measure in the PACE Trial.
The bimodal scale itself has been criticised as having limited validity and a potential for misuse (Pittinger
DJ. Journal of Career Planning and Employment 1993:54:48‐53). It has also been criticised because
preference score methods are not bimodal, as they are not a meaningful categorical division of a continuous
variable, which argues against its recommendation (Matthews PR. eBMJ 23 August 2004).
Christine Hunter of The Alison Hunter Memorial Foundation raised vital questions about outcome
measures that the Trial Investigators have not mentioned:
“What precise measures will be used to assess benefit from these trials? For instance, improved swallowing, less
abdominal pain and distension, less vomiting, improved gastric emptying, reduced diarrhoea, weight gain, able to cease
nasogastric tube feeding, or headache eased, rolling over in bed unaided? “Will the beliefs of the researchers be
strongly associated with/reliably predict the trial outcomes?” (http://web.archive.org/web/20070831234729/
http://ahmf.org/medpolpace.htm).
Many in the international ME/CFS community have little doubt about the answers to those questions, not
least because such severely affected patients are excluded from study.
Analyses
There are serious concerns about the analyses of the PACE Trial data; these concerns relate not only to the
chosen entry criteria but also to the listed covariates.
Section 12 of the full 226 page Trial Protocol states at 12.3.2: “Secondary analyses of efficacy – The secondary
continuous outcomes will be analysed by repeated measures analysis of variance using a linear mixed model with
AR(1) covariance structure, and including centre, depressive disorder, CDC and London criteria and baseline values
as covariates”.
The Oxford criteria
As noted above, the entry criteria for the PACE Trial are the psychiatrists’ own criteria (the 1991 Oxford
criteria).
The Oxford criteria have never been adopted internationally. There is no consensus about them; they are
used only in Britain and only by the Wessely School. As noted above, they lack diagnostic specificity, have
been shown to have no predictive validity, and to select a widely heterogeneous patient population. It is
virtually unheard of for studies to use criteria that have been superseded (as mentioned above, Michael
Sharpe himself – who was lead author of the Oxford criteria ‐‐ stated in 1997 that the Oxford criteria “have
been superseded by international consensus”.
The Oxford criteria stipulate that people with “organic brain diseases” are to be excluded. ME is a
classified neurological disorder, therefore the correct application of the entry criteria would result in the
screening out of people with ME from the PACE Trial.
There can be no credible doubt that the Oxford case definition excludes those with neurological disorders
and as noted above, this was confirmed in 1991 by psychiatrist Anthony David (colleague of Simon Wessely
and co‐author of the Oxford criteria): “British investigators have put forward an alternative, less strict,
operational definition which is essentially chronic fatigue in the absence of neurological signs (but) with
psychiatric symptoms as common associated features” (Postviral syndrome and psychiatry. AS David.
British Medical Bulletin 1991:47:4:966‐988).