The MAintaining MusculOskeleTal Health (MAmMOTH) Study

Chronic widespread pain (CWP), the cardinal feature of fibromyalgia, is associated with lost work productivity, psychological ill health, and poor quality of life. It is one of the most common reasons for referral to a rheumatologist. The cost of CWP is high in terms of both individual, societal and health costs: for example, in the United States, mean per-patient costs (including pain and non-pain-related medication, physician consultations, tests and procedures, and emergency department visits) in the 6 months following a new diagnosis of fibromyalgia have been reported as $3481, comparable to patients with rheumatoid arthritis but resulting in worse quality of life. Current guidelines recommend pharmacological, physical, and psychological therapies although the importance attributed to individual therapies is inconsistent. There is good evidence for musculoskeletal pain conditions generally that the longer the duration of symptoms, the less likely that symptoms are to improve, including with specific interventions. This is particularly so for CWP which, once developed, is challenging to manage and effect improvement.

A systematic review and meta-analysis of randomised controlled trials (RCT) of Cognitive Behaviour Therapy (CBT) for patients with fibromyalgia concluded that CBT improves coping with pain, reduces depressed mood and healthcare-seeking behaviour in such patients. The delivery of CBT by telephone has been shown to be effective, acceptable and accessible. The MUSICIAN study, which the investigators have recently concluded, tested telephone delivered CBT (tCBT) and/or exercise for patients with chronic widespread pain consulting to their GP. Three months after the end of therapy, both interventions resulted in significantly better primary outcome measures (patient global health) than treatment as usual, but there was no significant additional benefit of receiving both interventions. Recent analyses have demonstrated these benefits are maintained 2 years after the end of therapy. The investigators have conducted a comprehensive literature review with the aim of identifying randomised trials which had the aim of preventing the onset either of CWP or fibromyalgia. This review did not identify any such published trials. Further, a search of 11 international clinical trials registers/databases (including US, UK, Europe, Australia/New Zealand, Japan), undertaken in Autumn 2013 did not identify any ongoing trial with the aim of preventing the onset of CWP (or fibromyalgia).

There are several reasons why it may be desirable to try to prevent CWP onset, namely that the majority of CWP patients do not have important symptom improvement with current management (even within trials). Prediction models from epidemiological studies have been developed to identify "high risk" patients, which makes such an approach feasible. Research using the General Practice Research Database has demonstrated that prior to receiving a diagnosis of fibromyalgia in primary care, persons have a long-term prior history of consultation with symptoms. Although this will be the first prevention trial in this area, the concept of prevention using CBT has been addressed in musculoskeletal disorders with respect to intervention in neck pain and low back pain before people become patients and in mental disorders.

The investigators have conducted prospective epidemiological studies which have demonstrated that it is possible to identify "high risk" groups. In the first study, a high risk group for CWP onset was identified on the basis of two factors: somatic awareness (using the Somatic Symptom Scale) and illness behaviour (using the Illness Behaviour Score). This was replicated in a second study conducted by the applicants. These "aetiological models" excluded pain and therefore the investigators have re-analysed data from the latter study (also considering pain status) to identify the best predictors of onset and which results in a model more suitable for use in prevention studies. The resulting "at risk model" requires regional pain and two of the following: maladaptive behavioural response to illness), a high number of somatic symptoms, and sleep disturbance. In the second "validation" study, from a population of 2,374 persons without CWP, 653 satisfied the definition of "high risk of CWP" of whom 139 had developed CWP twelve months later (that is a Positive Predictive value of 21.3%). Amongst persons not deemed to be at high risk (n=1721), 77 developed CWP which is a Negative Predictive Value of 95.5%.

The investigators have previously shown short and long-term effectiveness of tCBT for CWP (compared to usual care). Specifically this demonstrated sustained improvement in patient global assessment of change, reduced psychological distress, fear of movement and reliance on passive coping styles. Secondly the investigators have developed and refined statistical models which identify persons at high risk for the future development of CWP. The investigators therefore now propose a study to test whether tCBT can reduce the risk of CWP onset amongst those at high risk.