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​PACE update: latest analysis and comment

March 22, 2018

A study published today in the journal BMC Psychology, which examines data from the PACE trial and evaluates the conclusions from the trial as a whole, raises "serious concerns about the robustness of the claims made about the efficacy of CBT and GET.”

Rethinking the treatment of chronic fatigue syndrome states: "The PACE trial was a well-powered randomised trial designed to examine the efficacy of graded exercise therapy (GET) and cognitive behavioural therapy (CBT) for chronic fatigue syndrome. Reports concluded that both treatments were moderately effective, each leading to recovery in over a fifth of patients. However, the reported analyses did not consistently follow the procedures set out in the published protocol, and it is unclear whether the conclusions are fully justified by the evidence."

In their conclusion, the study’s authors led by Dr Carolyn Wilshire, Victoria University of Wellington, New Zealand, state that "the various treatment effects reported in the PACE trial were modest, almost entirely confined to self-report measures, and did not endure beyond two years. If one were to ask, 'Given the procedures used here, what pattern of results would we expect if these therapies did not produce genuine change?' the answer would be, 'Modest, short-lived changes in self-report behaviour unaccompanied by objectively measurable changes' — a pattern much like the one obtained [...] The time has come to look elsewhere for effective treatments."

Quoted in a BBC News report on today’s study, the PACE trial's original authors have said that they "find little of substance in this critique and stand by our original reports."

Action for M.E. comments:

We welcome this latest re-analysis, which adds to the ongoing scientific debate around the methodology, conduct and clinical value of the PACE trial, and a growing lack of consensus among experts regarding the efficacy of CBT and GET for M.E. and/or CFS.

Specifically, we support this study's conclusion that research into effective treatments must move away from behavioural approaches and focus instead on the pathophysiology of the condition and its phenotypes. Action for M.E. actively supports investment in collaborative research that helps us stratify the illness, identify biomarkers, and ultimately lead to better treatments, and hopefully a cure.

We would also like to highlight our concerns regarding the Science Media Centre statement, published yesterday in advance of the re-analysis, and its dismissal of the significant scientific debate, and the growing lack of consensus, about appropriate treatments and clinical guidelines for M.E. and/or CFS.

This lack of consensus is evidenced by the decision taken by the Centers for Disease Control and Prevention, the leading national public health institute of the United States, to stop recommending CBT and GET, following careful consideration of peer-reviewed research, including the Institute of Medicine (IOM)’s 2015 report on M.E.

This has considerable implications for the current review of the National Institute of Health and Care Excellence (NICE) clinical guideline for M.E./CFS in the UK, given that NICE has an ethical obligation to present a full, accurate and balanced picture of current international clinical practice – including the lack of international consensus around the efficacy of CBT and GET. Action for M.E. will continue to highlight this to NICE throughout its consultation on its guideline for M.E./CFS.