A respected science journal is to withdraw a much-cited
review of evidence on an illness known as chronic fatigue syndrome (CFS) amid
fierce criticism and pressure from activists and patients.
The decision, described by the scientists involved as
“disproportionate and poorly justified”, is being seen as a victory for
activists in a research field plagued by uncertainty and dispute over whether
CFS, also known as myalgic encephalopathy (ME), has physical and psychological
elements.
Emails seen by Reuters show editors at the influential
Cochrane Review journal asking researchers who conducted the analysis, which
was published in April 2017, to agree to it being temporarily withdrawn.
They also ask the
review’s authors to agree to a statement saying their analysis requires
“further work in response to feedback and complaints”.
Published on the Cochrane Database of Systematic Reviews,
Cochrane’s evaluations are considered a gold standard in scientific literature
and known internationally as dispassionate analyses of the best evidence on a
given subject.
It is unusual for Cochrane to withdraw a review without the
authors’ agreement and unless new scientific evidence emerges for inclusion in
an update.
Research into CFS and ME, widely referred to by the joint
acronym CFS/ME, is highly contentious — in part because the illness is poorly
understood. It is a severe, chronic illness characterized by long-term physical
and mental fatigue.
Patient groups in the United States, Europe, Australia and
elsewhere often challenge each other about the nature of the disorder, how it
should be diagnosed and whether it can be treated. Scientists conducting
studies on potential therapies say they are often harassed and verbally abused
by groups that disagree with their approach.
Colin Blakemore, a professor of neuroscience and philosophy
at London University’s School of Advanced Studies, said the withdrawal decision
set a worrying precedent for scientific evidence being over-ridden by the
opinions of activists.
The withdrawal would also be “a departure from the principle
that has always guided Cochrane reviews — that they should be based on
scientific and clinical evidence ... but not influenced by unsubstantiated
views or commercial pressures.”
Blakemore has no affiliation with the Cochrane review
authors and has not conducted studies in CFS/ME, but he experienced lobbying by
activists when he was chief executive of Britain’s Medical Research Council from
2003 to 2007.
The review at the
center of this dispute, written by a team headed by Lillebeth Larun, a
scientist at the Norwegian Institute of Public Health, looked at eight
randomized controlled studies of exercise therapy as a treatment for patients
with CFS/ME.
Graded exercise therapy involves taking a patient’s activity
level right back to a minimum, and then gradually increasing it within their
capability.
The review found “moderate quality evidence” to show the
approach can help some CFS/ME patients, concluding: “Exercise therapy had a
positive effect on people’s daily physical functioning, sleep and self-ratings
of overall health.”
But in an email seen by Reuters, Cochrane editors Rachel
Churchill and David Tovey say the review had received “extensive feedback”
which they now considered grounds for it to be temporarily removed.
Tovey confirmed to Reuters that he had made a decision to
withdraw the review temporarily, saying this would give the authors time to
respond to several points in a complaint which “we felt ... raised issues we
needed to address”.
“This not about patient pressure,” he added in a telephone
interview. “This was a decision we reached with difficulty because we know the
incredibly challenging environment this review sits in.”
In their Oct. 15 email, addressed to Larun, Churchill and Tovey
wrote: “We are ... temporarily withdrawing your review to allow you and your
co-authors time to adequately address the feedback received. Consequently, your
review will shortly be removed from the Cochrane Library.”
Larun told Reuters
she was “extremely concerned and disappointed” with the Cochrane editors’
actions. “I disagree with the decision and consider it to be disproportionate
and poorly justified,” she said.
In an emailed
response to questions from Reuters, Tovey said: “We are in discussion with the
review author team about this review following a formal complaint to me as
Cochrane’s editor in chief, which we judged to raise important questions.”
Larun said she would
not characterize this as a discussion, but as a unilateral decision made by
Cochrane editors.
CFS/ME is thought to affect as many as 2.5 million people in
the United States and around 250,000 people in Britain, although estimates vary
widely due to a lack of formal diagnostics.
The condition can bring crushing fatigue, joint pain,
headaches and sleep problems and can render patients bed- or house-bound for
years. While the cause is a mystery, some theories point to a viral trigger.
On treatments, evidence from at least 10 published studies —
including the 2017 Cochrane Review — shows psychological approaches such as
graded exercise and cognitive behavioral therapy can help some CFS/ME patients
improve.
Yet critics say this
amounts to a suggestion that the syndrome is a mental disorder, or “all in the
mind”. They campaign fiercely to block or discredit any research looking at
psychological or behavioral treatments, arguing that they are physically, not
psychologically, debilitated.
Tovey and
Churchill said in their email to Larun that “in response to concerns raised by
members of the CFS community” they are considering moving responsibility for
research reviews on CFS/ME away from their mental health department into
another section — possibly the “long-term conditions” section.
Categorizing CFS/ME under mental health disorders “has been
antagonistic to some in the CFS community, potentially impacting on the
confidence people have in our reviews”, they wrote.
Blakemore said this was a sign of Cochrane’s editors
sidelining evidence under pressure from CFS/ME campaigners who insist their
illness is a physical disease and not a psychological disorder.
He also warned of the risk of wider effects on all patients
if a respected scientific journal like Cochrane “capitulates” to lobbying from
small numbers of vocal patient campaign groups.
“This could change medical practice,” he said. “And that
could mean that patients with this very serious condition are denied access to
treatments that might help them, and which evidence suggests can help some of
them.”
On the decision to move CFS/ME work out of the Cochrane’s
mental disorders section, Tovey confirmed to Reuters that this was made in
response to feedback from CFS/ME patients and campaigners.
CFS/ME is a “complex” disorder and categorizing it in the
mental health section “clearly causes some offense”, he said.
Courtesy of Doximity
Larun L, Brurberg KG, Odgaard-Jensen J, Price JR. Exercise
therapy for chronic fatigue syndrome. Cochrane Database Syst Rev. 2017 Apr 25;4
Abstract
BACKGROUND:
Chronic fatigue syndrome (CFS) is characterised by
persistent, medically unexplained fatigue, as well as symptoms such as
musculoskeletal pain, sleep disturbance, headaches and impaired concentration
and short-term memory. CFS presents as a common, debilitating and serious
health problem. Treatment may include physical interventions, such as exercise
therapy, which was last reviewed in 2004.
OBJECTIVES:
The objective of this review was to determine the effects of
exercise therapy (ET) for patients with CFS as compared with any other
intervention or control.• Exercise therapy versus 'passive control' (e.g.
treatment as usual, waiting-list control, relaxation, flexibility).• Exercise
therapy versus other active treatment (e.g. cognitive-behavioural therapy
(CBT), cognitive treatment, supportive therapy, pacing, pharmacological therapy
such as antidepressants).• Exercise therapy in combination with other specified
treatment strategies versus other specified treatment strategies (e.g. exercise
combined with pharmacological treatment vs pharmacological treatment alone).
SEARCH METHODS:
We searched The Cochrane Collaboration Depression, Anxiety
and Neurosis Controlled Trials Register (CCDANCTR), the Cochrane Central
Register of Controlled Trials (CENTRAL) and SPORTDiscus up to May 2014 using a
comprehensive list of free-text terms for CFS and exercise. We located
unpublished or ongoing trials through the World Health Organization (WHO)
International Clinical Trials Registry Platform (to May 2014). We screened
reference lists of retrieved articles and contacted experts in the field for additional
studies SELECTION CRITERIA: Randomised controlled trials involving adults with
a primary diagnosis of CFS who were able to participate in exercise therapy.
Studies had to compare exercise therapy with passive control, psychological
therapies, adaptive pacing therapy or pharmacological therapy.
DATA COLLECTION AND ANALYSIS:
Two review authors independently performed study selection,
risk of bias assessments and data extraction. We combined continuous measures
of outcomes using mean differences (MDs) and standardised mean differences
(SMDs). We combined serious adverse reactions and drop-outs using risk ratios
(RRs). We calculated an overall effect size with 95% confidence intervals (CIs)
for each outcome.
MAIN RESULTS:
We have included eight randomised controlled studies and
have reported data from 1518 participants in this review. Three studies
diagnosed individuals with CFS using the 1994 criteria of the Centers for
Disease Control and Prevention (CDC); five used the Oxford criteria. Exercise
therapy lasted from 12 to 26 weeks. Seven studies used variations of aerobic
exercise therapy such as walking, swimming, cycling or dancing provided at
mixed levels in terms of intensity of the aerobic exercise from very low to
quite rigorous, whilst one study used anaerobic exercise. Control groups
consisted of passive control (eight studies; e.g. treatment as usual,
relaxation, flexibility) or CBT (two studies), cognitive therapy (one study),
supportive listening (one study), pacing (one study), pharmacological treatment
(one study) and combination treatment (one study). Risk of bias varied across
studies, but within each study, little variation was found in the risk of bias
across our primary and secondary outcome measures.Investigators compared
exercise therapy with 'passive' control in eight trials, which enrolled 971
participants. Seven studies consistently showed a reduction in fatigue
following exercise therapy at end of treatment, even though the fatigue scales
used different scoring systems: an 11-item scale with a scoring system of 0 to
11 points (MD -6.06, 95% CI -6.95 to -5.17; one study, 148 participants;
low-quality evidence); the same 11-item scale with a scoring system of 0 to 33
points (MD -2.82, 95% CI -4.07 to -1.57; three studies, 540 participants;
moderate-quality evidence); and a 14-item scale with a scoring system of 0 to
42 points (MD -6.80, 95% CI -10.31 to -3.28; three studies, 152 participants;
moderate-quality evidence). Serious adverse reactions were rare in both groups
(RR 0.99, 95% CI 0.14 to 6.97; one study, 319 participants; moderate-quality
evidence), but sparse data made it impossible for review authors to draw
conclusions. Study authors reported a positive effect of exercise therapy at
end of treatment with respect to sleep (MD -1.49, 95% CI -2.95 to -0.02; two
studies, 323 participants), physical functioning (MD 13.10, 95% CI 1.98 to
24.22; five studies, 725 participants) and self-perceived changes in overall
health (RR 1.83, 95% CI 1.39 to 2.40; four studies, 489 participants). It was
not possible for review authors to draw conclusions regarding the remaining
outcomes.Investigators compared exercise therapy with CBT in two trials (351
participants). One trial (298 participants) reported little or no difference in
fatigue at end of treatment between the two groups using an 11-item scale with
a scoring system of 0 to 33 points (MD 0.20, 95% CI -1.49 to 1.89). Both
studies measured differences in fatigue at follow-up, but neither found
differences between the two groups using an 11-item fatigue scale with a
scoring system of 0 to 33 points (MD 0.30, 95% CI -1.45 to 2.05) and a
nine-item Fatigue Severity Scale with a scoring system of 1 to 7 points (MD
0.40, 95% CI -0.34 to 1.14). Serious adverse reactions were rare in both groups
(RR 0.67, 95% CI 0.11 to 3.96). We observed little or no difference in physical
functioning, depression, anxiety and sleep, and we were not able to draw any
conclusions with regard to pain, self-perceived changes in overall health, use
of health service resources and drop-out rate.With regard to other comparisons,
one study (320 participants) suggested a general benefit of exercise over
adaptive pacing, and another study (183 participants) a benefit of exercise
over supportive listening. The available evidence was too sparse to draw
conclusions about the effect of pharmaceutical interventions.
AUTHORS' CONCLUSIONS:
Patients with CFS may generally benefit and feel less
fatigued following exercise therapy, and no evidence suggests that exercise
therapy may worsen outcomes. A positive effect with respect to sleep, physical
function and self-perceived general health has been observed, but no
conclusions for the outcomes of pain, quality of life, anxiety, depression,
drop-out rate and health service resources were possible. The effectiveness of
exercise therapy seems greater than that of pacing but similar to that of CBT.
Randomised trials with low risk of bias are needed to investigate the type,
duration and intensity of the most beneficial exercise intervention.
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