The PACE Trial – ‘Illegal’ Participants skew the data

Changing the Protocol to admit less severely ill patients was rather desperate.  But then concocting the outcome measure ‘Normal Range’ which meant that some participants had recovered before they started, has made a laughing-stock of the PACE Trial.  But what did it do to the data?  Actually, it is not dreadful, but then again, it is not science.  Splitting the treatment groups into ‘legal’ and ‘illegal’ participants illustrates the difference between them.  Participants are ‘legal’ if their baseline score is BELOW the threshold of ‘Normal Range’ (60).  They are ‘illegal’ if their baseline is equal to or above that score – because, well, you just can’t do that!  It’s DUMB.

CBT group SF36PF

CBT group SF36PF.

Baseline score 55 or less n=128

Baseline score 60 or more n=20:

i.e., already ‘Normal Range’

Legal Participants Illegal Participants
Baseline Average  = 36 Baseline Average  = 62
Outcome Average = 56 Outcome Average = 75

The ‘illegal’ CBT participants who joined the Trial already at ‘Normal Range’ had these SF36PF outcomes:
80% scored 60 or more and were ‘Normal Range’
60% scored 75 or more and were ‘Improved’ as per the Protocol
45% scored 85 or more and were ‘Recovered’ as per the Protocol

 

 

SMC group SF36PF

SMC group SF36PF.

Baseline score 55 or less n=128

Baseline score 60 or more n=22:

i.e., already ‘Normal Range’

Baseline Average  = 34 Baseline Average  = 62
Outcome Average = 47 Outcome Average = 71

The ‘illegal’ SMC participants who joined the Trial already at ‘Normal Range’ had these SF36PF outcomes:
82% scored 60 or more and were Normal Range
50% scored 75 or more and were ‘Improved’ as per the Protocol
23% scored 85 or more and were ‘Recovered’ as per the Protocol

Conclusion

The incredible blunder of positioning an outcome threshold BELOW the level required for participation has had an effect on the outcome.  The overall influence has been limited due to the Control Group, but in a Trial where the researchers were evidently scrabbling for a few points here and there, the influence has significance.

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