P. D. White, K. Goldsmith, A. L. Johnson, T. Chalder and M. Sharpe ; PACE Trial Management
Psychological Medicine, Page 1 of 9. Cambridge University Press 2013
What does this paper really show?
Research into psychogenic medicine frequently redefines words to mean quite different things from the standard word, then are used in ways in which it is hard to disambiguate the meanings. Superficial reading or investigation might lead someone to infer the original meaning of the word. This has even been touted as useful as it means doctors can lie to patients to achieve their goals without alienating as many patients, such as using the word "functional".
This is the case with the word "recovery". This paper does not supply recovery information, just as the preceding two papers didn't. It describes bluk information, a word I just made up only to discover it refers to a language.
To disambiguate what is going on, I am going to redefine "recovery" as "bluk", "bluked" etcetera. Psychogenic medicine does this all the time, so why shouldn't I?
Bluk is not to be confused with bluk, the language: http://www.urbandictionary.com/products.php?term=Bluk&defid=5522125
With the definitions of bluk used in the paper, what does this really show? 22% of the patient cohort were bluked by the end of the study. This means that they achieved sufficient SF-36 improvement to qualify as having at least the physical capacity as someone 65-85 (based on the differing population norms in various papers) even if they are only 30. Normally we let people of that physical capacity retire in peace, but not so the bluked.
These bluked patients were able to be shown to be subclinical with respect to two definitions of CFS and one of ME. David Bell's study from a few years ago looked at 10 bluked patients who were examined and all found to be sick just not so sick that they would still be considered a patient in a clinic. So bluk means "less sick".
The Oxford criteria is a vague and probably heterogenous definition that is not widely used outside of the UK and a few countries in Europe. It is not the international research standard - neither the old one (Fukuda) nor the new one (CCC). It is known (Leonard Jason's research) that Oxford defined cohorts typically have lots of patient with other problems, including depression. They typically do not have neurological signs either. Furthermore, even in the UK there is published evidence of a very high misdiagnosis rate using this criteria in practice.
Reeves (2003) CDC criteria is so "greatly" regarded that not many aside from the CDC use it. Its largely irrelevant in the research world.
The London ME criteria commands some respect, given that that ME, "benign" myalgic encephalomyelitis, has a much longer history than CFS and was the definition given to a large number of disease clusters. However this is a modifed version and this version is not validated.
So bluk means patients no longer fulfilling definitions of CFS and ME that are either not commonly used or properly validated. It says nothing about cohorts using modern definitions like the CCC or ICC.
Based on the two prior PACE papers, we know bluk was not shown to translate into improved functional capacity. Receipt of benefits actually went up. The 6-minute walking test results were pathetic. This fits with the conclusion that, at best, bluk means less sick. Further it appears that this cohort was only slightly less sick, not very less sick.
The number needed to treat to show improvement and the number needed to treat to show bluk indicates that there are two groups of patients: those that are improve, and those that probably don't. This seems like a way too obvious thing to say, but its important to disambiguate improved patients with non-bluked patients and even patients who worsened. Some patients improve, some probably don't, some probably get worse, and some are bluked.
Since the bluked patients are claimed to have made substantive bluk, it is not clear what the bluk status of the rest is. Were they just non-bluked, or anti-bluked? In other words, was there a substantive decline to match the improvement in the bluked patients, so that the aggregate results come out kind of blah like they did?
This can only be disambiguated if full SF-36 results are published for all patients, including their score at the start of the trial. Keep in mind though that this paper makes the claim that objective functional capacity measures may not be valid because they do not match subjective patient measures. This is actually reason to do the opposite, and abandon SF-36 and similar instruments for CFS and ME in favour of objective measures. This problem could have been at least partly corrected if they showed the bluked patients had much better 6 minute walking test scores.
Favouring subjective measures over objective measures makes this study at best one from the social sciences, not from hard sciences, though to be fair social science has evolved a long way in its capacity for self-reflection, self-criticism and open debate. Its not clear psychogenic medicine is there yet.
When we disambiguate using a made up word, rather than the confusing highly ambivalent words used in the psychogenic literature, its easier to reason about without becoming confused.
Feel free to use the words bluk, bluked etcetera in future. Please do not mis-spell the word by adding a "c" to it. My brain autocompleted the word "bluk" with a "c" way too many times. I wouldn't want people to become confused and autocomplete it by replacing the "b" with an "f" either.
This is not one of my scheduled blogs, its entirely due to the recent publication of the third PACE paper.