NICE on chronic pain

On 7 April 2021, the National Institute for Health and Care Excellence, or NICE, published its guidelines on the diagnosis and management of chronic pain (NG193). I published the first version of this post the same day. Two years later (26 July 2023), I am revising my post because much was poorly written, and there is more to say. Chronic pain gives rise to many challenges. It is common, not easily alleviated, and usually associated with other long-term symptoms such as reduced concentration. The aetiology and underlying mechanisms still need to be fully understood. It is rarely attributable to any specific ongoing tissue damage, and the widely used biomedical model of illness cannot explain it; the biopsychosocial model allows a much better analytic framework. Philosophers use chronic pain to explore the nature of experience. They also debate where the pain is – or is it anywhere? NICE is more down to earth and has developed the guidelines well. I will follow my original outline but revise and improve the details.

Table of Contents


Since writing the first version, I have published other pain posts, including chronic non-malignant pain and pain experienced by people with a prolonged disorder of consciousness. Both have explored some physiological and experiential aspects of pain, and both touch on philosophical questions such as, where is the pain felt? I have removed those discussions from this post.

All healthcare must prioritise the reduction of pain and distress, and rehabilitation is no exception; most patients we see will experience both. Rehabilitation clinicians and services must become experts at diagnosing and managing pain. Most pain seen in rehabilitation is chronic, so the guideline is relevant to rehabilitation. I will focus on the NICE approach, reviewing it critically from the rehabilitation perspective.

What is chronic pain?

The NICE guideline describes chronic (more than three months) primary pain; thus: “Chronic primary pain has no clear underlying condition or the pain (or its impact) appears to be out of proportion to any observable injury or disease.” They say: “ICD-11 gives examples of chronic primary pain, including fibromyalgia (chronic widespread pain), complex regional pain syndrome, chronic primary headache and orofacial pain, chronic primary visceral pain and chronic primary musculoskeletal pain.”

NICE is aware that pain can arise without tissue damage. They are also mindful of the need for a holistic approach looking at many other factors; they say: “The experience of pain is always influenced by social factors (including deprivation, isolation, lack of access to services), emotional factors (including anxiety, distress, previous trauma), expectations and beliefs, mental health (including depression and post-traumatic stress disorder) and biological factors. When assessing chronic primary pain and chronic secondary pain, these potential contributors to the presentation should be considered.

In this context, I anticipated a guideline to acknowledge that chronic pain is often one of the many functional somatic disorders, albeit not directly or by name. I also expected some mention of the biopsychosocial model of illness as a framework for analysing the many factors contributing to a person’s experience of pain. What did I find?

NICE on chronic pain - strong points

There is much that is good.  The guideline acknowledges that all pain requires attention from healthcare services and that a person may have both pain due to tissue damage and pain that is unexplained and not associated with tissue damage.

The first specific recommendation is for a person-centred assessment, which Robert Smith argues should always be based on the biopsychosocial model of illness. There are many sensible, practical recommendations on approaching diagnosis and giving information.

The section on assessment includes a part on developing a care and support plan that starts with three bullet points that are integral to rehabilitation, saying:

Explore in the discussions:

  • their priorities, abilities and goals
  • what they are already doing that is helpful
  • their preferred approach to treatment and balance of treatments for multiple conditions.” [It needs to be clarified exactly what this is referring to.]

The section on managing chronic primary pain again recommends interventions that are integral to all effective rehabilitation, with some additional details and approaches:

  • Exercise programmes. The evidence presented was extensive and showed benefits with uncertainty about the size of the benefit. The evidence did not show any specific type of exercise was better.
  • Psychological therapy. One the evidence found, they recommended Acceptance and Commitment Therapy or Cognitive Behavioural Therapy. Oddly, biofeedback was included in this domain, and they concluded it should not be offered.
  • Acupuncture. The evidence presented, and the subsequent discussion emphasise the low quality and risk of bias; on the other hand, there was no evidence of significant risk of harm.
  • Drugs. The evidence reviewed led NICE to recommend anti-depressant medication. However, they also recommended one should not use many medicines, including:
    • Anti-epileptic drugs, anti-psychotic drugs, benzodiazepines, steroid injections in trigger points, ketamine, local anaesthetics, non-steroidal anti-inflammatory drugs, opioids, or paracetamol
  • Electrical modalities. After reviewing the evidence, they recommended not using
    • transcutaneous electrical stimulation, ultrasound, or interferential therapy.

The other outstanding aspect is the evidence they have reviewed and made available. (here)

What needs to be added.

There are a few things that could be improved. These do not concern any specific recommendations; they concern recommendations not made, ideas not mentioned, and evidence not used.

Many patients with chronic pain (as defined by NICE) are already seen in expert rehabilitation services and are managed successfully. Many (but possibly not all) chronic pain services provide excellent rehabilitation, and almost all understand the biopsychosocial model of illness. Organisations such as the British Pain Society emphasise the multifactorial nature of chronic pain and the importance of a multiprofessional approach.

The widespread failure to use the terms rehabilitation or biopsychosocial model has consequences. Patients seen outside a named pain service may need help understanding they receive high-quality care. They ask to leave and be referred to a pain service, disrupting a successful management programme. Conversely, patients being seen in a pain service may not appreciate they are receiving rehabilitation or that a rehabilitation service might increase their level of physical and social function.

Professionals and services are more likely to take a holistic view using the biopsychosocial model of illness, which facilitates a person-centred approach. There is a risk that both the service and the professionals will restrict their input to ‘controlling the pain’ rather than ‘living with the pain’ and increasing patient activities. Patients usually use the medical model to understand their illness and thus expect a cure for their pain rather than improving their quality of life. In another post, I have drawn on qualitative research to highlight the importance of this more positive approach.

It continues the illusion that the biomedical approach is the only approach because the NICE guideline does not (dare) name the biopsychosocial model. Consequently, some people who read the NICE guidance have not been introduced to the model. My blog post on the model (link above) outlines the harms associated with this illusion.

A systemic failure.

NICE’s strengths include taking a broad view, considering costs and quality of life when assessing the value of healthcare activities, having a transparent approach to identifying and evaluating evidence, and avoiding bias when making judgements as far as possible.

I am concerned that NICE is unwilling or unable to acknowledge that much of healthcare is not well-served by adherence to a single disease-centred, specific treatment-oriented approach when identifying and interpreting evidence. Despite its focus on costs, societal benefits, and quality of life, NICE seems wedded to the biomedical sickness model and sometimes takes an inflexible approach.

One illustration is its failure to mention or use the biopsychosocial model of illness. This has been known for nearly 50 years and used widely, for example, in many clinical areas such as low back pain. It is the intellectual basis of the World Health Organisation’s International Classification of Functioning. Nonetheless, the word does not appear once in guidelines on low back pain (CG88), Long-Covid (NG 188, NG 191), Chronic pain (NG193), multiple sclerosis (CG186), or Chronic Fatigue Syndrome (CG53 and NG206).

This cannot be due to unawareness by the organisation, NICE, in the guise of their researchers or panel members for the various guidelines. The biopsychosocial model must have been mentioned in the evidence for these guidelines and by experts discussing the evidence. Yet the word does not appear once in my search of the .pdf documents.

I speculate that acknowledging the validity of the biopsychosocial model of illness raises so many questions about their methodology that it is easier to say it is irrelevant. The increasing recognition of Functional Neurological Disorders and other functional disorders and the overwhelming evidence of the importance and relevance of social and psychological factors in all illnesses, including all biomedically-caused illnesses, will eventually require a change.

I think the failure to acknowledge the role of expert rehabilitation has a more complex explanation, and I can only suggest some factors. One is that rehabilitation is explicitly based on the biopsychosocial model of illness. Full acknowledgement of what expert rehabilitation is and does pose a significant challenge.

Coupled with that, rehabilitation is a long-term process with many complex interventions, and this is not easily managed in a system that focuses on single, usually short and time-limited, easily defined interventions. It is all too messy for people who are used to close control over everything.

Thirdly, NICE considers rehabilitation to be only a treatment with a dose; they do not consider it a process. Yet they would not evaluate surgery as an intervention, asking if more surgery was better than less. The method includes specific interventions, which can and should be studied using trials.

Even then, the NICE methodology is based on disease diagnosis, whereas the treatments may target an impairment such as spasticity. There is no reason to think spasticity is significantly different in people with stroke from people with multiple sclerosis or traumatic brain injury. Yet, only evidence from pure stroke studies will be used.

Rehabilitation focuses on a person’s function and aims to improve subjective well-being and social integration. The problems are complex, and many factors influence the outcome. In addition, the management is a complex intervention, rarely a single identifiable action or drug.

The next 25 years of NICE

The Medical Research Council (MRC) recognised that complex interventions required an appropriate, adapted, scientifically sound research approach in 2000, modified in 2006, and now renewed in 2021 with the National Institute for Health and Care Research (NIHR). A new framework for developing and evaluating complex interventions: update of Medical Research Council guidance.

They framed a complex intervention as “events in systems”, which describes rehabilitation. The events are the process of assessment and formulation, planning and coordination, multiple interventions, and evaluation and reiteration. The systems are the biopsychosocial model and the broader healthcare and social care systems. They note that these are complex, adaptive systems.

They suggest six core elements need to be considered:

  • The context of the intervention. The setting may determine the outcome. Moreover, different environments may have other emerging properties or variations in feedback mechanisms and may adapt or reorganise in alternative ways when the intervention is introduced.
  • The theory underlying the programme of intervention
  • The stakeholders, anyone who is involved or impacted by the intervention, including policymakers and commissioners
  • The key uncertainties present need to be handled using a “flexible and emergent approach”, recognising that uncertainty and unpredictability are characteristic of complex systems.
  • Refinement of the intervention in the light of emerging evidence or new theoretical insights
  • Economic or resource considerations, comparing costs, benefits, and harms of alternative approaches if available.

Avril Drummond and I reviewed the approach of NICE in their stroke rehabilitation guidance and made three recommendations.

Three major factors must be considered carefully.

  • Scope of the guideline, which must be comprehensive:
    • if resources are limited, selection should be based on a scientifically sound assessment of the frequency and importance of the clinical problems and not on the personal opinions of a small number of people.
  • Scope of the evidence that will be considered, which must include all evidence relevant to any particular question:
    • Systematic searching must be adapted to the specific question and must not be driven by primary disease diagnosis.
  • Evaluation of the evidence, which must recognise that rehabilitation involves:
    • complex interventions delivered usually by people to patients;
    • a likelihood of influencing several outcomes at different levels;
    • major problems or actual impossibility in blinding patients and treating therapists.

There will be no simple way to approach this challenge. NICE has been incredibly successful since April 1st, 1999. One way to celebrate the last 25 years would be to prepare for the next 25 years when the complexity of healthcare and healthcare interventions will inevitably become more challenging. The previous methodology is becoming increasingly stressed, as exemplified by the recent experience of the second guideline on managing chronic fatigue syndrome.


This NICE guideline on the diagnosis and management of chronic pain for which there is no disease explanation has a series of sensible recommendations at the individual level. Most of them are based on a biopsychosocial model of illness, though this is not acknowledged. Most of them are typical approaches used in expert rehabilitation services, though this is not recognised. The evidence identified is extensive, but the methods used to evaluate and interpret evidence can be improved. This guideline follows many other policies on similar conditions in ignoring the biopsychosocial model of illness and, more importantly, its implications for identifying and using evidence. It also shows a failure to acknowledge the nature of rehabilitation. The increasing complexity of healthcare problems and interventions, the forthcoming 25th anniversary of NICE’s birth, and the recent work by the Medical Research Council and the National Institute of Health and Care Research offer an excellent opportunity.

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