ME/CFS Primer/Education Bulletins Comment on the results of the PACE trial

The results of the PACE trial in terms of treatment efficacy for both Cognitive Behavioural Therapy (CBT) and Graded Exercise Therapy (GET) are extremely modest to say the least and certainly not by any stretch of the imagination remotely curative—a decrease in fatigue score (range 0-33) at 52 weeks of 3.4 and 3.2 points respectively, and an increase in physical function score (range 0-100) of 7.1 and 9.4 points for each treatment respectively, compared with standard medical care. (1)

This despite the adoption of the Oxford criteria, which are so broad that they clearly fail to exclude patients with primary psychiatric diagnosis in the absence of physical symptoms. (2)

Conversely the results of a another large scale evaluation of the efficacy of both CBT and GET conducted in Spain and published earlier this year demonstrated that after 12 months, intervention with CBT and GET not only failed to improve health-related quality of life HRQL scores but led to worse SF-36 physical function and bodily pain scores in the group receiving these treatments compared with standard medical care alone. (3)

It is of interest that two such similar studies both utilising comparable timescales, interventions and measures of outcome should produce such discrepant and diametrically opposed results.

Even if we take the results of the PACE trial at face value, of the 3158 patients presenting with fatigue at specialist Chronic Fatigue Syndrome clinics for potential inclusion in the PACE trial, only 641 were eventually selected for inclusion in the study. This means that 4 out of every 5 potential participants were excluded. This is remarkable—given the obvious delay between primary outpatient appointment and specialist hospital CFS clinic attendance most if not all would naturally meet Oxford criteria in the absence of major psychosis, organic brain disease and substance abuse. How only 1 in 5 of these were eventually selected for inclusion in the study and the exact criteria for such exclusion leading to such an unusual/unrepresentative ME/CFS sample are questions that must warrant further investigation.

—David Sampson, BSc (Hons), MSc, MBPsychS



(1) White et al. (2011) Comparison of adaptive pacing therapy, cognitive behaviour therapy, graded exercise therapy, and specialist medical care for chronic fatigue syndrome (PACE): a randomised trial. The Lancet; Published Online February 18, 2011 DOI: 10.1016/S0140-6736(11)60096


(2) Sampson D.P. (2010) Close Analysis of a Large Published Trial Into Fatigue Syndromes and Mood Disorders That Occur After Documented Viral Infection. Bulletin of the IACFS/ME, Vol 18, Issue 2, Summer 2010.

(3)  Núñez M, Fernández-Solà J, Nunez E, Fernandez-Huerta JM, Godás-Sieso T,  Gomez-Gil E. (2011) Health-related quality of life in patients with chronic fatigue syndrome: group cognitive behavioural therapy and graded exercise versus usual treatment. A randomised controlled trial with 1 year of follow-up. Clinical  Rheumatology. 2011 Jan 15. (E-publication ahead of print)