PACE trial

A clinical trial for chronic fatigue syndrome

The PACE trial (Pacing, graded Activity, and Cognitive behaviour therapy: a randomised Evaluation) was a large-scale clinical trial conducted in the United Kingdom to evaluate the effectiveness of different treatments for chronic fatigue syndrome (CFS), also known as myalgic encephalomyelitis (ME). The trial was funded by the UK government and published its main results in 2011.

Background

Subjective outcomes of the PACE trial

Chronic fatigue syndrome is a complex and debilitating disorder characterized by extreme fatigue that cannot be explained by any underlying medical condition. The fatigue worsens with physical or mental activity but does not improve with rest. The cause of CFS is unknown, and it is often a diagnosis of exclusion.

The PACE trial aimed to assess the effectiveness of four different treatments for CFS: adaptive pacing therapy (APT), cognitive behavioural therapy (CBT), graded exercise therapy (GET), and specialist medical care (SMC) alone. The trial was conducted across multiple centers in the UK and involved over 600 participants.

Methods

The PACE trial was a randomized controlled trial, which is considered the gold standard in clinical research. Participants were randomly assigned to one of the four treatment groups. The primary outcomes were self-reported measures of fatigue and physical function, assessed using the Chalder Fatigue Scale and the SF-36 physical function subscale, respectively.

Treatment Groups

• Adaptive Pacing Therapy (APT): APT is based on the principle of pacing, which involves balancing activity and rest to avoid exacerbating symptoms.
• Cognitive Behavioural Therapy (CBT): CBT is a psychological treatment that aims to change patterns of thinking or behavior that are causing people's problems, and so change the way they feel.
• Graded Exercise Therapy (GET): GET involves a structured and supervised increase in physical activity, tailored to the individual.
• Specialist Medical Care (SMC): SMC involved standard medical care provided by a specialist in CFS/ME.

Results

The results of the PACE trial indicated that both CBT and GET were more effective than APT and SMC alone in improving self-reported fatigue and physical function. However, the trial's methodology and findings have been the subject of significant controversy and debate within the scientific community and among patient advocacy groups.

Controversy and Criticism

The PACE trial has been criticized for several reasons, including its reliance on subjective outcome measures, changes to the study protocol after the trial began, and the interpretation of the results. Critics argue that the trial's conclusions overstate the effectiveness of CBT and GET and that the treatments may not be suitable for all patients with CFS/ME.

Impact

Despite the controversy, the PACE trial has had a significant impact on the treatment guidelines for CFS/ME in the UK and internationally. It has influenced clinical practice and the development of treatment recommendations by health organizations.

Related pages

• Chronic fatigue syndrome
• Myalgic encephalomyelitis
• Cognitive behavioural therapy
• Graded exercise therapy