White et al have distinguished between normal and recovery (but failed to make this clear on their paper or during their 15 minutes of fame at the press conference before being parroted by journalists), so the best thing about
oceanblue's find is that White was commenting on
normal. Up until then, we had White & Bleijenberg & Knoop on
co-authored record for using [mean minus SD] on a healthy group to arrive at >=80/100 points as a threshold for
recovery, and Bleijenberg on
co-authored record for using <=65/100 as the cutoff point to "reflect severe problems with physical functioning".
Bleijenberg & Knoop were not involved in the PACE Trial but wrote the accompanying editorial in the Lancet which falsely claimed that PACE used a "strict criterion for recovery" based on "healthy" persons' scores (>=60/100 threshold), even though PACE did not actually report on recovery nor use scores from a healthy group. Such a sloppy blunder, as if they never even read the paper they were commenting on, defies belief and AFAIK remains uncorrected to this day despite complaints and even a
rumoured intention of eventual correction. How else can it be explained that the same people once thought 60-65 reflected "severe problems" in function and now is a "strict criterion for recovery"?
PS - This is what the notorious
Reeves et al 2005 "empirical" CDC criteria for CFS has to say:
We defined substantial reduction in occupational, educational, social, or recreational activities as scores lower than the 25th percentile of published US population [11] on the physical function (≤ 70), or role physical (≤ 50), or social function (≤ 75), or role emotional (≤ 66.7) subscales of the SF-36.
11. Ware JE, Sherbourne CD: The MOS 36-item short form health survey (SF-36): conceptual framework and item selection. Med Care 1992, 30:473-483.
