Can you tell from the paper what the 'several criteria for ill health' were? Does it relate to that SPF-factor thingy? Thanks.
And what's with the ME? Several times I have heard the claim that ME was excluded from this Trial although I never really felt that what I think it was White said should have been taken literally. Any thoughts? Thanks.
The several criteria for ill health and recovery are described in the text but the results are in Table 1:
1)
A normal range in fatigue and physical function. Despite clarifying in 2011 that this is not recovery, this is now the base or mandatory criteria for recovery (the remaining are optional add-ons). Yes, it is based on the CFQ score for fatigue (<=18 points out of 33, Likert scoring) and SF-36 score for physical function (>=60 points out of 100). Both thresholds here overlap with the entry criteria for "disabling fatigue": >=6 points out of 11 for fatigue in bimodal scoring (18 points Likert scoring can be anywhere between 4-9 points in bimodal score), and <=65 points in physical function.
2)
No longer meeting Oxford criteria. The Oxford criteria is ambiguous on what is significant fatigue and disability, so PACE added additional criteria to it here, which is the same threshold used to define "disabling fatigue" at trial entry as mentioned above. In other words, <=5 points in fatigue (bimodal), and >=70 points in physical function is now regarded as a recovery. Note that in the original protocol, <=3 points in fatigue (bimodal, so 4 and above was regarded as abnormal) and >=85 points in physical function, these were the threshold for recovery. Adding this to the normal range criteria barely changes the figures of recovery at all, which seems odd to me. It also leaves open the possibility that without the additional criteria for fatigue and physical function, people who are "recovered" from CFS in PACE could still be diagnosed with Oxford criteria CFS if they went elsewhere and felt that their fatigue and physical function were abnormal for them (e.g. 2/3 of the general population score 95 or 100 points in physical function and would not think 70 is a full recovery).
3) A CGI (clinical global impression) score of 1 i.e. "very much better" or 2 i.e. "much better". Adding this onto the previous two criteria for recovery does significantly lower the recovery rates, which suggests that a significant proportion of the "recovered" participants only felt slightly better from baseline. Also note that in the original definition of recovery, only 1 or "very much better" was regarded as the CGI criterion for recovery.
As for the CDC criteria for CFS and London criteria for ME, it is unsurprising that adding these on does little to the recovery rates since the Oxford criteria is broad and everyone who meets the CDC criteria or London criteria but not the Oxford criteria were already weeded out before the trial began. Also, by changing the symptom requirement from 6 months to one week, they do not appear to have used the CDC criteria properly anyway.
As to whether ME patients were studied, this is more complicated. For the purposes of PACE, ME was not regarded as an "organic brain disease". However, the medical assessment in PACE may have excluded some clinical characteristics which are allowed in ME criteria. Also, PACE only included candidates if their only main symptom was fatigue, which is not a requirement in other definitions. ME focuses on other symptoms more, symptoms which PACE relegate. I would guess some ME patients did get in though, but whether or not the London ME criteria could locate them is another matter.
I think it is misleading for White et al to claim that their report on recovery is both "comprehensive" and "conservative". They go as far as erroneously claiming it was more conservative than the paper by Knoop et al (2007) when it seems to be the opposite, particularly for the physical function score anyway. The peer-reviewers should have at least demanded that the original definition of recovery be added onto the top of the hierarchy for comparison. Why did White et al abandon them? Their claim that
"we made the changes before analysis and to more accurately reflect recovery" is unconvincing.