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Implicit Bias in the Patient Cohort

Posted by TerryE on 10 Jan 2010 at 23:30 GMT

in the UK CFS population.

The CFS patient cohort was selected from attedees at the KHC CFS clinic (the "Clinic"), by a normalisation process. This comment does not relate to that process or the subsequent methodology, however it's conclusion refers to "the UK CFS Population". More strictly it should refer solely to the KHC CFS clinic population, but the paper makes the assumption that this latter population is representative of the UK CFS population as a whole because it falls within a broad statistical measure based on the Chalder Fatigue Scale.

This assumption is weak and could be criticised on the following basis:
* The CFS patient community is a broad spectrum of sufferers from who feel that it is a broad biopsychosocial illness to those who feel that it is entirely biological in origin.
* The Clinic's professional staff are psychiatrists, psychologists and related specialities who have a proven track record in CBT and GET for those patients who value such treatments.
* Unfortunately there is a history of antagonism between many ME/CFS communities and the Clinic leadership, because of its strong psychological stance and treatment options and its championing current NICE Guidelines.

The Clinic patient group is therefore largely prefiltered by:
* the ability to take part in routine clinic attendance at SE5 (when most chronic CFS sufferers struggle to leave their houses, and many their beds);
* showing no evidence of detectable organic illness (does POTS fall into this category);
* willingness to take part in take part in a CBT or neuroendocrine study (when most CFS suffers reject such psychological explanations and treatments).

My assertion is that is a de facto pre-filter which elimates the very category of CFS suffers who have an XMRV infection from the trial.

One way of countering this assertion would be to do a small repeat trial with a cohort who have tested positive with a CFS biomarker. Why not a sample drawn from Dr Myhill's Mitochondrial Dysfunction Study cohort (PMID: 19436827). (This would not be an endorsement of her study or her findings, but merely a way of identifying a cohort of chronic CFS patients with positive biomarkers which is accepted by the wider CFS patient community, and a stratum that has been effectively excluded from this study.

Competing interests declared: I am a CFS sufferer.

RE: Implicit Bias in the Patient Cohort

PLOS_ONE_Group replied to TerryE on 20 Jan 2010 at 20:50 GMT

Due to a technical problem with our site, a comment that was left on this thread between 5 pm PST 1/17/10 and 3 am PST 1/20/10 has been lost.
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Competing interests declared: PLoS ONE Staff