“Got ME? Just get out and exercise, say scientists.”
(Independent: 18th Feb 2011)
“Talking and exercise could cure ME.”
(Sky News: 18th Feb 2011)
Headlines like these have become increasingly common in recent years. They refer to the results of the PACE trial, a government-funded study into the safety and efficacy of graded exercise and cognitive behavioural therapies (GET/CBT) as treatments for ME.
The trial ostensibly showed that structured exercise can be used to treat ME, but ME specialists condemn the research as flawed, misleading and potentially harmful. No one denies the importance of patients remaining as active as possible within safe limits; the question is whether goal-focussed programmes that push against those limits are helpful or harmful when it comes to ME.
There are a number of in-depth analyses already available on line, but I would like to highlight some of the issues that make this seemingly innocuous subject so controversial.
1. PACE promotes the theory that ME has a primarily psychosocial cause
Despite substantial evidence for the physical basis of ME, psychiatrists behind the PACE trials believe it to be a form of personality disorder perpetuated by psychosocial factors.
The theory is that ME starts with an ordinary virus. Rather than rest the patient tries to push through their symptoms, becoming progressively worse as a result. Once forced to take bed-rest the virus swiftly resolves but the patient fails to recognise their recovery. Because earlier attempts at activity made their symptoms worse the patient remains inactive and becomes deconditioned. Deconditioning makes exercise difficult, perpetuating the false belief that the patient is ill and that exercise will harm them.
Plausible as this theory sounds, it has very little basis in fact. Attempts to prove the psychosocial model have achieved precisely the opposite: studies have shown that ME patients do not suffer from exercise phobia, are no more prone to personality disorders than patients with any other chronic illness and are no more deconditioned than healthy, sedentary controls who do not feel ill doing normal physical activities.
2. Many patients report that graded exercise made them sicker
Results of PACE seem very different to patient experiences of graded exercise. Surveys of patients found the majority claim to have had no benefit from exercise or to have wound up sicker, yet the PACE trial claimed 60% of participants improved. My own experience of graded exercise has been largely detrimental and ME specialists cite post-exertional malaise (a defining symptom of ME) as proof that graded exercise is harmful.
Physical exertion has been repeatedly shown to have a measurable effect on patients with ME, causing muscle abnormalities, neurocognitive impairments, decreased motor speed, poor reaction times, reduced peak flow and abnormal brain activity. People with ME have a reduced capacity to recover from exertion and this exercise intolerance has a cumulative effect until patients reach a point where their capacity for exertion actually decreases.
The PACE researchers acknowledge that poorly-delivered graded exercise can make patients worse but the UK has very few physiotherapists qualified to deliver specialist care. Of my six experiences of graded exercise, only one involved a therapist with experience of ME. I don’t know whether exercise, or poor execution was responsible for my own decline but my recovery has been far more consistent without graded exercise than it ever was with it.
3. Patient selection for the PACE trials was extremely controversial
I have written before about the problems of including ME under the umbrella of chronic fatigue syndrome which has no internationally agreed diagnostic criteria. The PACE trials were based upon the Oxford criteria for CFS/ME, which focuses on fatigue as the primary symptom. The focus on idiopathic fatigue means patients with misdiagnosed or co-morbid psychiatric diagnoses (such as depression, anxiety, and somatoform disorders) were not excluded from the trial. All these disorders are known to cause fatigue and to respond to exercise and CBT.
By the PACE researchers’ own reckoning only 67% of patients met the American CDC criteria for CFS and only 51% met the London Criteria which focuses on the exercise-induced fatigue required for diagnosis in the UK. Patients with primary symptoms other than fatigue were excluded from the trial as were children and anyone with severe ME, meaning its results cannot be extrapolated beyond a certain subgroup of patients.
This is particularly important as many doctors (and the media) attempt to apply the results universally. The NICE guidelines specifically state that graded exercise is not recommended for severe ME and another trial conducted at the same time as PACE showed treatment based on CBT and GET was not beneficial to house-bound adults. Unlike PACE, the FINE trial barely featured in the press.
4. Data from the trial has been widely misrepresented
Two forms of assessment were used to measure patients’ fatigue in the trial: subjective patient questionnaires and an objective six-minute walking test. Figures quoted in the press were based upon patient perceptions of fatigue but the extent of perceived improvement was not substantially upheld in physical tests.
At the start of the trial, patients averaged a distance of approximately 300 meters in a six-minute walking test. The authors of the trial proposed a forty-five meter improvement as providing a ‘clinically useful’ outcome. The group that received medical care alone improved by twenty meters while the group that received graded exercise improved by thirty-five. As the graded exercise was in addition to medical care however, the first twenty meters of improvement may be attributed to this, meaning only fifteen meters can be attributed to the exercise itself. Few people would deny that a fifteen meter improvement after a year of therapy is hardly a miracle cure.
The furthest distance completed in the walking test was only half the average distance of a typical healthy pensioner. Fatigue levels were still higher at the end of the trial than for patients with congestive heart failure. As all the patients in the trial were receiving some form of treatment the results don’t indicate whether any of these treatments are significantly more effective than no treatment at all.
As fatigue is only one of many disabling symptoms of ME, a reduction in fatigue does not necessarily equate to a return to health or improvement in physical and social function. No data about patient recovery or deterioration has yet been published, so media claims that patients were ‘cured’ or returned to ‘normal’ following the trial are unsupported. There is no evidence that patients came off benefits or returned to work as a result of the trial, in fact receipt of benefits was found to have increased. Given ME is characterised by periods of remission and relapse it will be interesting to see whether improvements are sustained in the longer-term.
To GET or not to GET?
The truth is it is hard to know quite what to believe. Specialists on both sides of the divide offer very different advice and few GPs are well enough informed to offer a reassuring opinion. Refusal to co-operate with graded exercise can be seen as proof of a behavioural disorder but specialist treatment is not available in many areas and poorly delivered exercise treatments bring a high risk of relapse.
Every patient has heard horror stories about the dangers of graded exercise but most have heard the recovery stories too. Every sufferer I know has been told at some point that if they just do a bit of exercise they’re sure to be cured, but just because it says so in the Mail or the Times, doesn’t necessarily make it true.
At most, GET and CBT can claim to be a moderately effective form of symptom management, applicable to a particular subgroup of patients; they are certainly not the miracle cure that media pundits report them to be.
In the end it should fall to the patient to make a free and unpressured choice; whatever they decide, they are the ones who must live with the consequences.
Over to you:
What are your opinions on the PACE trial?
Are there any specialist ME physiotherapists in your area?
Have you ever tried graded exercise therapy and did you find it helpful or harmful?