BMJ 1996;312:22-26 (6 January) Papers Cognitive behaviour therapy for the chronic fatigue syndrome: a randomised controlled trial Michael Sharpe, clinical tuto In this study 30 patients with medically unexplained fatigue were to be subjects of CBT and standard medical treatment and 30 given medical treatment Patients in the CBT group were told to avoid bedrest and increase their level of excercise The purpose of CBT from sharpes point of view was to change the patient.s false beliefs about biological cauation of their illness.progress was adjudged to have been made if the patients questioned these beliefs and reported more correct beliefs that causation was psychological. All patients who had a history or reported symptoms that aroused suspicion of a medical cause for their fatigue were excluded Patients were asked to report on their activity levels over the previous month and the psychiatist attributed points based on the patients reporting to a disability scale.The one used was the Karnofsky scale which is used to measure the functional level of cancer patients. Patients were also asked to assess the severity of their symptoms on a subjective patient rating scale Severity of fatigue was rated on a scale of Sharpe's own devising Anxiety and depression were also measured. Patients were also asked to walk for six minutes and distance covered in that time measured. Good endpoints of treatment were predetermined according to the trialists criterea of a good or satisfactory response irrespective of what the patients actually said.This was either a karnofsky points total of 80 or more or an increase of ten points. Now normal function does not mean functioning normally! The following is an example of a 10% improvement in the karnolfsky score # 70% - caring for self, not capable of normal activity or work # 60% - requiring some help, can take care of most personal requirements They reported that 73% of patients had a score of 80 or more with CBT and medical treatment compared with only 23% with medical treatment alone.This means that only 8 out of 30 patients had any benefit with medical therapy.Yet the difference in percentage improvements is reported as a range between 69% and 22%.The psychiatrist reported the opinion that some patients experienced a 69% improvement in Karnofsky score over medical treated patients while for some patients the improvement in their opinion was as low as 22%.Now remember only 8 patients showed any improvement over medical treatment at all.Yet they reported in improvement over medical treatment in 22 patients.This means that a maximum of 14 patients have been compared to patients who showed no improvement at all. To put it simply 69% improvement over 0% improvement is no improvent at all. patients were able to walk further in 6 minutes by an average of 41 metres.but were not able to walk for longer than 6 minutes yet this is supposedly a clinically significant benefit.Scientifically the differences between the two groups was not significant.to make matters worse a number of patients in the CBT group had estimated values recorded for the distances they covered-Why? The final assessment significant subjective improvement ("much improved" or "very much improved") was reported by 60% (18/30) of the patients who received cognitive behaviour therapy and 23% Note there was no option of no change.