A reanalysis of the controversial PACE trial into treatment of chronic fatigue syndrome has found that recovery rates reported in the original trial were inflated fourfold.
Published in the Lancet in 2011, the PACE trial compared the effects of adding cognitive behavioural therapy, graded exercise therapy (GET; a progressive increase in exercise), or adaptive pacing therapy ( a gradual increase in activity) to standard care (a leaflet containing advice) in patients with chronic fatigue syndrome.
Patients were randomised to each intervention but the trial was unblinded.
At the time the authors reported a benefit for CBT and graded exercise, but not for adaptive pacing.
However a re-analysis of the original data published in the Virology Blog now throws significant doubt on the findings.
Together with Philip Stark, from the department of statistics at the University of California, and Bruce Levin, professor of biostatistics at Columbia University, New York, Matthees reanalysed the recovery rates published in the trial using the thresholds specified in the trial protocol.
They discovered that the recovery rates were reduced, with 3.1% for specialist medical care alone, 6.8% for CBT, 4.4% for graded exercise therapy, and 1.9% for adaptive pacing therapy.
“This re-analysis demonstrates that the previously reported recovery rates were inflated by an average of four-fold,” they wrote in the Blog published last week.
“Furthermore, in contrast with the published paper by the trial investigators, the recovery rates in the cognitive behavioural therapy and graded exercise therapy groups are not significantly higher than with specialist medical care alone.”
“The changes made by the PACE trial investigators after the trial was well under way resulted in the recovery criteria becoming too lax to allow conclusions about the efficacy of CBT and GET as rehabilitative treatments for CFS,” they concluded.
In an interview with The BMJ Peter White, leader of the PACE trial and professor of psychological medicine at Queen Mary University London, said that the reanalysis on the Virology blog used more stringent thresholds for recovery than those used in the trial.
“It is no surprise that this resulted in fewer people apparently recovering. How do they know that they used the right recovery thresholds? Our results were similar to those of two previous studies, which gives us some confidence in the findings,” he told The BMJ.
In another Blog posted on Virology Dr David Tuller, academic coordinator of the concurrent masters degree program in public health and journalism at the University of California, Berkeley called the PACE trial “a fraud”.
“Ever since Virology Blog posted my 14,000-essord investigation of the PACE trial last October, I’ve wanted to write that sentence. (I should point out that Dr. Racaniello has already called the PACE trial a “sham,” and I’ve already referred to it as “doggie-poo.” I’m not sure that “fraud” is any worse. Whatever word you use, the trial stinks,” he wrote.