Findings from a controversial medical trial which claimed psychotherapy and exercise helped patients with ME were not reliable, a new study has found.

The PACE trial, which was funded by the Medical Research Council, aimed to establish the best way to treat sufferers of myalgic encephalomyelitis, otherwise known as chronic fatigue syndrome.

When its results were published in 2011, researchers claimed that graded exercise therapy (GET) and cognitive behavioural therapy (CBT) were “moderately effective” forms of treatment, each leading to recovery in more than a fifth of patients.

But the study has since faced intense criticism from patients and charities, including the ME Association, over how the results were obtained, analysed and presented.

Unpublished data from the trial was eventually released and has now been independently re-analysed.

The paper, published in the journal BMC Psychology, found that the benefits reported for psychotherapy and exercise therapy were modest and not statistically reliable.

Lead author Dr Carolyn Wilshire, from the University of Wellington in New Zealand, said: “Our re-analysis was designed to explore how the PACE trial outcomes would have looked if the investigators had adhered to the primary outcome they described in their original published protocol.

“We also looked into the published data on long-term outcomes to examine whether they had been influenced by the treatments patients had received after the trial had ended.

“We found that the groups receiving CBT or GET did not significantly outperform the control group after correcting for the number of comparisons specified in the trial protocol. Rates of recovery were consistently low and not significantly different across treatment groups.”

In surveys carried out by the ME Association, more than half of patients who had followed the recommended graded exercise programme saw a worsening in their symptoms.

Dr Charles Shepherd, honorary medical adviser to the ME Association, said: “This sends a powerful message to the research community that they must be willing to share data where there are serious concerns about protocols or the reliability of results from a clinical trial.

“The ME Association believes that it is very important to encourage research data sharing and, where appropriate, independent re-analysis – which is why we made a significant financial contribution towards the processing fee for publication of this paper.

“The message is clear – CBT and GET are not effective ways of treating a serious neuroimmune disease. The sooner this message gets across to health professionals the better.”

ME is a chronic, long-term neurological condition that can lead to severe, persistent fatigue although symptoms can vary from person to person.

It affects an estimated 250,000 people in the UK, according to the charity Action for ME.