Investigator bias and the PACE trial

Abstract

The PACE investigators reject Geraghty's suggestion that the cognitive behavior therapy/graded exercise therapy trial could have been better left to researchers with no stake in the theories under study. The potential sources and standards for determining researcher bias are considered, concluding that the PACE investigators "impartiality might reasonably be questioned."

Graded exercise therapy does not restore the ability to work in ME/CFS – Rethinking of a Cochrane review

“…If their trials had failed to show significant improvement and recovery through GET, this would have undermined the very theories of reversibility to which the investigators have dedicated their careers. Consequently, the risk of latent bias was palpable from the outset [55]. It is notable that Jason et al (2007) [11], the only study conducted by a researcher without an allegiance to the model, concluded that none of the four treatment strategies was "superior to another treatment strategy in all areas.…”

Rethinking the Standard of Care for Myalgic Encephalomyelitis/Chronic Fatigue Syndrome

“…However, given the important influence of the PACE trial on the standard of care, the potential biasing effects of subjective measures have been more closely examined. 16 Overall, objective outcomes 17 did not support PACE efficacy claims based on self-report measures. Of the four objective measures in the PACE trial, i.e., 6-min walk test, fitness step test, days lost from work, 18 and percent on disability benefits, none were found to show a selective benefit for CBT or GET.…”

“…The cognitive behavioral model of chronic fatigue syndrome posits that the symptoms and debility of ME/CFS are the result of deconditioning, originating from patients' fear of activity and false cognitions that the illness is physical. 16,19,20 As stated in the PACE trial manual: 9 BAccording to this model, the symptoms and disability of ME/CFS are perpetuated … by unhelpful [fear-based] illness beliefs and [avoidant] coping behaviours^(p. 18). Thus, CBT interventions for chronic fatigue syndrome focus on changing illness beliefs (cognitions) to promote increased activity (behavior).…”

Cognitive behavioural therapy for myalgic encephalomyelitis/chronic fatigue syndrome is not effective. Re-analysis of a Cochrane review

“…If their trials had failed to show significant improvement and recovery through CBT, that would have undermined the very theories of reversibility to which the investigators have dedicated their careers. Consequently, the risk of latent bias was palpable from the outset (Lubet, 2017). It is notable that the study conducted by a researcher without an allegiance to the model, concluded that none of the four treatment strategies was superior to another treatment strategy in all areas (Jason et al, 2007).…”