Can cognitive behavioural therapy thwart chronic widespread pain?

For individuals at high risk of chronic widespread pain (CWP), a short course of telephone-delivered cognitive–behavioural therapy (CBT) is cost effective and favourably affects quality of life, although falling short of preventing the onset of pain, according to data from the MAMMOTH* study.

“Most people eligible for the trial probably would not have known what CWP is, nor that they were at high risk of its development. Thus, the intervention was described as ‘maintaining musculoskeletal health’ and introduced in the context of participants having reported pain and other symptoms,” the investigators explained.

“It demonstrates that a low-cost, short-duration intervention benefits a wider range of people with musculoskeletal symptoms than previously considered,” they added.

Conducted in UK, MAMMOTH included 996 participants (median age, 59 years; 59 percent female) who had around one in four chances of developing CWP 1 year later based on reports of somatic symptoms, sleep problems, and aspects of illness behaviour. They were randomized to receive either usual care (UC; n=496) or a short course of telephone CBT (n=500). None of the patients reported pain related to fibromyalgia.

At 12 months, there were similar numbers of participants in the CBT and UC arms who developed CWP (18.0 percent vs 17.5 percent; odds ratio [OR], 1.05, 95 percent confidence interval [CI], 0.75–1.48). [Ann Rheum Dis 2021;doi:10.1136/annrheumdis-2020-219091]

However, compared with UC, CBT resulted in better quality of life (mean difference in EQ-5D-5L utility score, 0.024, 95 percent CI, 0.009–0.040) and larger quality-adjusted life-years (difference, 0.023, 95 percent CI, 0.007–0.039) at an additional cost of £42.30 (95 percent CI, −451.19 to 597.90). This translated to an incremental cost-effectiveness ratio of £1,828.

CBT consisted of an initial assessment, six weekly 30–45-minute sessions over 6 weeks, and then booster sessions at 3 and 6 months. These sessions covered education about musculoskeletal pain, somatic symptoms, and specific coping techniques such as pacing of activity, behavioural activation, diary keeping, identifying and challenging negative and unhelpful thinking patterns, and the development of a longer-term management plan.

On the other hand, UC involved no additional intervention, reflecting the fact there is no specific intervention provided to patients currently for the prevention of CWP.

Explaining the results, the investigators pointed out that CBT may not be effective in relation to preventing onset of as opposed to managing CWP. “Our previous trial using [the same intervention] in the management of CWP, while showing large improvement in patient perception of their condition and in quality of life, did not demonstrate any benefit in terms of the Chronic Pain Grade.” [RMD Open 2015;1:e000026]

Additionally, CWP is influenced by early life factors, “so it could be that intervening across the adult age range is too late to be effecting a change by means of a short-term intervention,” they said. [Pain 2009;143:92-96]

The investigators also cited the possibility that the current risk model may not be causal, thus it would be beneficial to explore, among those at risk, what is the underlying causal mechanism (eg, altered hypothalamic–pituitary–adrenal axis function). [Curr Pain Headache Rep 2004;8:116-124]

Finally, they acknowledged that CWP probably was a poor choice as the primary outcome. “There is evidence that people with CWP can move in and out of meeting criteria, and indeed it may be that we have identified people who commonly experience CWP but recruited them at a time when they did not meet criteria—and the interpretation would be that the intervention did not move participants off that trajectory.” [J Pain 2019;S1526-5900(19)30845-4]

*Maintaining musculoskeletal health