The PACE trial, conducted in 2011 to examine ME/CFS, was the most expensive study of the disease at the time, partly funded by the Department for Work and Pensions and then published in the Lancet. It purported to demonstrate that ME/CFS patients could recover with a regime of therapy and exercise designed to break bad mental and physical habits. PACE was uncritically accepted by public agencies and media around the world, and it would be used to influence international treatment guidelines for ME/CFS. But the PACE study has since been conclusively debunked. Its multiple faults include data manipulation, questionable methodology, and conflicts of interest. College courses now use it as an object lesson in how not to conduct a clinical trial, and a member of the UK parliament called it “one of the greatest medical scandals of the 21st century.” Among its many absurdities: The study included a bizarre paradox: participants’ baseline scores for the two primary outcomes of physical function and fatigue could qualify them simultaneously as disabled enough to get into the trial but already “recovered” on those indicators–even before any treatment. In fact, 13 percent of the study sample was already “recovered” on one of these two measures at the start of the study.

The PACE trial, conducted in 2011 to examine ME/CFS, was the most expensive study of the disease at the time, partly funded by the Department for Work and Pensions and then published in the Lancet. It purported to demonstrate that ME/CFS patients could recover with a regime of therapy and exercise designed to break bad mental and physical habits. PACE was uncritically accepted by public agencies and media around the world, and it would be used to influence international treatment guidelines for ME/CFS. But the PACE study has since been conclusively debunked. Its multiple faults include data manipulation, questionable methodology, and conflicts of interest. College courses now use it as an object lesson in how not to conduct a clinical trial, and a member of the UK parliament called it “one of the greatest medical scandals of the 21st century.” Among its many absurdities: The study included a bizarre paradox: participants’ baseline scores for the two primary outcomes of physical function and fatigue could qualify them simultaneously as disabled enough to get into the trial but already “recovered” on those indicators–even before any treatment. In fact, 13 percent of the study sample was already “recovered” on one of these two measures at the start of the study.