A landmark £5 million study that formed the basis for NHS treatment of ME sufferers has been heavily criticised for its “troubling” use of data, in new research that claims its recommendations were largely worthless.

Since 2011 the estimated 250,000 Britons with ME, also known as chronic fatigue syndrome, have been offered treatment based on exercise and cognitive behavioural therapy, after a study known as the Pace trial was published in The Lancet and seemed to show this approach improved symptoms.

Now, after a freedom of information request forced the scientists behind the 2011 study to release their raw data, other researchers have performed their own analysis. They said their study, published in the journal BMC Psychology, raised “serious concerns about the robustness of