Chronic primary pain: Navigating a new diagnostic entity

Abstract

Historically, pain has been viewed as a symptom of disease, rather than a disease state itself. In 2018, the World Health Organization released the International Classification of Diseases, 11th Revision (ICD- 11), and for the first time a systematic coding system for chronic pain was incorporated. This new classification introduced the term chronic primary pain (CPP), defined as pain not better accounted for by an underlying condition and associated with significant functional impairment or distress. Now, for the first time CPP has been recognised by the National Institute for Health and Care Excellence as a condition in its own right. This article aims to explore the definitions, diagnosis, and management of CPP and how this may be translated into day-to-day primary care practice.

Clinical case scenario

Emma, aged 42, attends with a longstanding history of generalised pain and stiffness, most notably in her neck and lower back. She feels fatigued and has difficulty sleeping. Physical examination, blood tests and imaging have been unremarkable.

You suspect a diagnosis of fibromyalgia. You establish how pain affects Emma’s life, as well as how life affects her pain. She discloses she is no longer able to work as a care home assistant due to her symptoms. She is a single parent and worries that she cannot be fully present for her two school-aged children. You validate Emma’s pain and explain that normal investigation results do not mean there is not a problem.

You provide information about chronic primary pain (CPP) and explore Emma’s management priorities and goals. Together, you formulate a care and support plan with focus on lifestyle modifications, and an exploration of what physical activities Emma might enjoy doing. She agrees to input from a social prescriber. You discuss the psychological therapies available in your area and Emma says she will consider them. She enquires about medication. Her friend takes gabapentin for similar symptoms. You discuss the lack of evidence regarding gabapentin for CPP and talk through the available options. Emma is keen to try pharmacological management, but does not want to take anything sedating. Together, you formulate a support plan and agree to prescribe a trial of duloxetine with a follow up double appointment scheduled for one month aiming to provide continuity of care.

The burden of chronic pain

Chronic pain conditions impose a significant clinical, social and economic burden and present a major public health issue. It has been estimated 1-in-10 adults are diagnosed with chronic pain per annum, with 20% suffering from pain globally (International Association for the Study of Pain (IASP), 2012). Approximately, 70% of chronic pain is managed in primary care (Breivik et al., 2006), comprising 22% of presenting complaints. Over one third of adult primary care consultations involve a patient living with chronic pain (Upshur et al., 2006). Recent estimates of the prevalence of pain within the UK indicate that approximately 44% of the population could be living with pain of mild to severe intensity, a figure that is likely to increase further as the population ages (Fayaz et al., 2016). The Global Burden of Disease Study 2016 confirmed that pain and pain-related conditions are the principal cause of disability and disease burden globally (Vos, 2017). More people suffer from persistent or chronic pain than diabetes, heart disease and cancer collectively (Tsang et al., 2008).

Chronic pain is often associated with development of a problematic series of physical and psychological changes. These include immobility, immunosuppression, sleep disturbance, medication dependence, social isolation and mental health issues (Lipman, 2009). Chronic pain is the most common reason for early retirement or work incapacity. Compared with the general population, the risk of having to leave employment is seven times higher for patients living with chronic pain (EFIC, 2014). Findings from the UK National Pain Audit demonstrate approximately 50% of patients with chronic pain report difficulties undertaking social activity, driving or walking, with 49% receiving a diagnosis of depression (Price et al., 2019).

Defining pain

The IASP defines pain as an ‘unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage.’ A range of biological, psychological and social factors interact to influence the complex perceptual experience of pain, which becomes a learned concept for an individual over time (IASP, 2023). Despite serving an important adaptive role, pain has potential adverse effects on a person’s functioning, including physical, emotional, interpersonal as well as recreational effects (Turk and Okifuji, 2002). Pain is defined as chronic when it lasts or recurs for greater than 3 months or beyond the expected period for tissue healing (Rahman, 2014).

Introducing chronic primary pain

The International Classification of Diseases, 11th Revision (ICD- 11) came into effect in January 2022 (World Health Organization (WHO), 2022). For the first time, a systematic coding system for chronic pain was incorporated, providing an opportunity for standardised coding throughout healthcare systems, as well as improvements in research and health policy decision making (Smith et al., 2019).

Multiple shortcomings had been identified with the former ICD-10 system, as well as the Diagnostic and Statistical Manual (DSM) published by the American Psychiatric Association, as the representation of pain diagnoses within these did not satisfactorily reflect recent advances in pain research, nor did they have clear implications for treatment and management (Cosci and Fava, 2016; Nicholas et al., 2019; Rief et al., 2012). This led to difficulty undertaking accurate epidemiological investigations and impeded health policy decisions (Treede et al., 2019). ICD-11 incorporates a multimodal approach, addressing the contributing biopsychosocial components of pain, with implications for management and treatment.

Chronic pain can be defined as either primary or secondary. In CPP, no clear underlying condition satisfactorily accounts for the pain or its impact whereas chronic secondary pain (CSP) is linked to a specific underlying condition (National Institute for Health and Care Excellence (NICE), 2021). CPP is defined as the presence of pain in one or more anatomical area(s), persisting or recurring for 3 months or longer, associated with significant functional disability or emotional distress, that cannot be better accounted for by an alternative diagnosis (Nicholas et al., 2019). Examples of CPP include fibromyalgia, chronic primary headache and orofacial pain, and chronic primary musculoskeletal pain. These subtypes are defined further in Fig. 1. Prior to the diagnosis of CPP, it must be determined whether the pain is attributable to a specific and recognisable cause, which would lead to a diagnosis of CSP; examples include osteoarthritis, rheumatoid arthritis, and neuropathic pain. CPP and CSP can co-exist (NICE, 2021).

Figure 1.

Subtypes and general classification structure of CPP. Examples of third-level diagnoses given, not limited to those listed. As per the novel construct of multiple parenting detailed in ICD-11, an entity can span more than one diagnosis.

Guidelines for chronic primary pain

In April 2021, NICE published a guideline for the assessment of all chronic pain and management of CPP in over 16s (NG193) (NICE, 2021). This was the first time CPP was recognised by NICE as a condition in its own right, aligning with ICD-11. The NICE guideline provides clinical practice guidance for the UK (aside from Scotland) and focuses primarily on the management of CPP, as for CSP condition specific guidance should be observed.

The recommendations put forward by NICE regarding CPP propose a person-centred assessment with identification of the factors influencing the pain and recognition of the impact of pain on a person’s daily life. They promote development of a collaborative relationship between healthcare professional (HCP) and patient, advocating shared decision making and creation of a care and support plan (NICE, 2021). See Box 1 for a summary of NG193 recommendations. Box 1.

Summary of NICE NG193 recommendations.

Undertake a person-centred assessment and develop a supportive relationship, in collaboration with the patient

Offer a supervised group exercise programme

Consider CBT or ACT

Consider a single course of acupuncture or dry needling

Analgesics are not recommended, including paracetamol, NSAIDS and opioids

Consider an antidepressant after discussion about risk and benefit

NICE emphasises non-pharmacological management of CPP, detailing options including supervised group exercise, psychological therapy such as acceptance and commitment therapy (ACT) or cognitive behavioural therapy (CBT), and acupuncture. Of note, NICE do not recommend transcutaneous electrical nerve stimulation, ultrasound or interferential therapy as electric physical modalities for the management of CPP, due to a lack of evidence of benefit. Perhaps the most noteworthy recommendation within the guideline is that most well-established analgesics should not be used in CPP management. These include paracetamol, non-steroidal anti-inflammatory drugs (NSAIDs), opioids, benzodiazepines and corticosteroid trigger point injections. Gabapentinoids and local anaesthetics are not recommended, unless as part of a trial for complex regional pain syndrome. If a patient with CPP is already established on any of these medications, review is recommended with explanation of the lack of evidence for use in CPP with encouragement to reduce and stop the medicine, or development of a shared plan for continuing safely should they be deriving benefit.

The NICE guideline states that use of an antidepressant may be considered for management of CPP in people aged over 18 years, specifying amitriptyline, duloxetine, citalopram, fluoxetine, sertraline or paroxetine as potential options. Prior to commencing antidepressant treatment, a detailed discussion regarding risks and benefits of the medication should be undertaken, as well as explaining that use may benefit quality of life, sleep, pain and distress, even in cases where no concurrent diagnosis of depression has been made.

The Scottish Intercollegiate Guidelines Network (SIGN) guidelines for Management of Chronic Pain are recommended for clinicians working in Scotland (SIGN 136) (SIGN, 2019). These were first published in December 2013, and more recently updated in 2019 in response to the growing evidence base regarding use of opioids in chronic pain. SIGN 136 recommends a multidisciplinary approach centred on a biopsychosocial assessment and a subsequent management plan encouraging non-pharmacological management strategies as well as appropriate pharmacological management (Colvin and Smith, 2020). SIGN 136 is not consistent with NICE NG193, specifically with reference to the recommendation that opioid medication may be considered in the short-to-medium term in carefully selected patients with chronic non-malignant pain, where other treatments have proved inadequate, and in situations where advantage outweighs risk (Smith et al., 2021). Upon commencing treatment, SIGN recommend shared agreement between patient and prescriber to guide effective and safe opioid use and review, with an agreed plan to reduce and stop the medication should treatment goals not be attained (SIGN, 2019).

Response to NG193

The 2021 NICE guidance has received a polarised response, with concerns raised by various organisations and calls to revise the guideline (Faculty of Pain Medicine (FPM), 2020; Korwisi et al., 2021; Smith et al., 2021). The British Pain Society have commented ‘the blanket and inexpert withdrawal of medication in such a vulnerable group of patients could easily lead to despair and unintended harm’ (Kmietowicz, 2021). As the term CPP remains a novel concept, research studies pre-dating its introduction reference different nomenclature. Authors argue the absence of the term ‘CPP’ in such studies should not be taken as a lack of evidence for CPP treatment options, and that such research should be considered when reviewing all available evidence (Korwisi et al., 2021). Cochrane reviews were excluded from the evidence analysis for various areas including, but not limited to, pharmacological, psychological, exercise and acupuncture. The FPM reported various concerns including the use of confusing terminology within NG193, and also expressed worries about the approach used to collate and interpret the evidence base (FPM, 2020). Given the heterogeneity of conditions that can present as CPP, concerns have been raised over the appropriateness of a ‘one size fits all’ approach to management, which has the potential to discount the unique needs presented by the individual conditions (Korwisi et al., 2021). By denying patients a trial of analgesia that has the potential to be efficacious increases the likelihood of continuing pain and distress (Smith et al., 2021).

The publication of NG193 has been viewed by some as sending a ‘hopeful message’, marking a significant paradigm shift in both the assessment and management of pain, underpinned by reducing harm from pharmacological treatments (Stannard and Bernstein, 2021). In general, the recommendations focussing on individualised patient assessment, combined with a shared decision-making approach have been welcomed (The British Pain Society (BPS), 2021). The vision and foresight employed by NICE when basing NG193 on the new ICD-11 classification has also been commended (Korwisi et al., 2021). The guidelines have the potential to empower the clinician, by an increased awareness of what treatments are not beneficial, thus being better able to guide patient expectations (Stannard and Bernstein, 2021).

Putting guidelines into practice

Within the UK, there has been a substantial increase in the workload of GPs. Between the years 2010–11 and 2014–15, face-to-face and telephone consultation numbers increased by 13% and 63%, respectively. However, the GP workforce expanded by only 4.75% in this time period (Hadi et al., 2017). Given the pressures of multimorbidity, an ageing population and ever-increasing patient expectations, GPs’ capacity for effectively managing chronic pain may be diminished (Hadi et al., 2017). NICE recommendations have been published at this time of exceptional workload, making implementation extremely challenging. Interim measures to help provide the time and space for potentially lengthy consultations may be possible, such as longer appointments and involvement of the multidisciplinary team (Stannard and Bernstein, 2021). Follow up with the same HCP may be beneficial, and help to foster and develop the therapeutic relationship (Kang et al., 2023).

Services representing non-pharmacological interventions for CPP are often lacking or under-resourced, leaving clinicians in the difficult position of refusing to prescribe analgesia, with likely resultant patient suffering (Harvey-Sullivan et al., 2022). Clinicians require support with signposting to services, as well as ensuring adequate commissioning of such services to effectively implement NG193. Support also needs to be in place when explaining this guidance to patients living with CPP, which can be challenging to undertake. This can be helped by HCPs having insight into a patient’s prior experience of sub-optimal interactions and consultations regarding their pain, as well as HCPs developing a clear appreciation of the evidence for use of various management options (Carville et al., 2021). Implementation of an effective communication approach can help patients with CPP feel listened to and believed. Validation of their pain and experiences can empower patients to develop strategies to better improve their own quality of life (Kang et al., 2023).

For ‘legacy patients’ already established on treatments that are not recommended within the guideline, clinicians need to be suitably skilled to formulate a staged reduction plan and initiate deprescribing where appropriate. In April 2021, The British Pain Society, the Faculty of Pain Medicine, The Chronic Pain Policy Coalition and the RCGP released a joint statement so as to provide clarification outlining what the NICE guidance means for patients already on medication (RCGP, 2021). This statement of clarification reports that the publication of NG193 should represent an opportunity for medication review within routine consultations. If a patient is deriving benefit from taking the medication, a plan can be developed between the HCP and patient using a shared decision-making approach, with explanation of the risks and lack of evidence for the medication use. However, if a patient reports no benefit, a plan to gradually reduce the medication can be formulated between the HCP and patient. Box 2 presents considerations and practical suggestions for putting NICE guidance into practice. Box 2.

Considerations at GP consultation.

Consider scheduling longer appointments, involvement of multidisciplinary team members and follow up with the same HCP to better foster an ongoing therapeutic relationship

Employ effective communication strategies: Listen to and validate the patient’s experience of pain

Share the diagnosis by explaining CPP and its multifactorial nature

Use routine consultations as an opportunity for medication review, and to assess benefit or lack of benefit of medications that are not recommended (e.g. opioids, NSAIDs)

Discuss the management options available. Use a shared decision-making approach to develop a management plan going forward

Conclusion

Chronic pain is a major global public health issue and a prominent cause of patient suffering and distress. Introduction of the first systematic classification for chronic pain within ICD-11 represented the establishment of CPP as a disease in its own right, with the aims of improving research and health policy decision making in the field of pain. Publication of recent NICE guidance provides a framework for clinicians for the assessment and management of CPP. Difficulties have been anticipated translating this guidance into day-to-day primary care practice, with commissioning of services and support needed. It is hoped that this guidance supports the development of a shared understanding of the experience of pain with collaboration between clinician and patient, while minimising harm.

Key points

Chronic pain is a massive global health issue, with approximately 1-in-10 adults diagnosed with chronic pain each year

The recent ICD-11 classification introduced the diagnosis of CPP, referring to chronic pain in the absence of a clear underlying condition

NICE guidance NG193 incorporates the new ICD-11 classification and recommends a person-centred approach, with shared decision making and fostering of a supportive and collaborative relationship with the patient

Scheduling longer appointments and follow up with the same GP may be beneficial; validating a patient’s experience of pain and explaining the diagnosis of CPP can help introduction of potential management strategies

NICE NG193 focuses on non-pharmacological options for CPP including supervised group exercise, psychological therapies such as CBT and ACT, and acupuncture; pharmacological options include certain antidepressants, but standard analgesics are not recommended

There are certain disparities between SIGN and NICE recommendations for managing CPP

Footnotes

ORCID iD

Dr Niamh Blythe

References

Breivik

Collett

Ventafridda

, et al. (2006) Survey of chronic pain in Europe: Prevalence, impact on daily life, and treatment. European Journal of Pain 10(4): 287–333. DOI: 10.1016/j.ejpain.2005.06.009.

Carville

Constanti

Kosky

, et al. (2021) Chronic pain (primary and secondary) in over 16s: Summary of NICE guidance. British Medical Journal 373: n895. DOI: 10.1136/bmj.n895.

Colvin

Smith

(2020) Key learning points: SIGN chronic pain—opioids, Available at: hwww.medscape.co.uk/viewarticle/key-learning-points-sign-chronic-pain-opioids-2022a10017a9 (accessed 7 July 2023).

Cosci F and Fava GA (2016) The clinical inadequacy of the DSM-5 classification of somatic symptom and related disorders: An alternative trans-diagnostic model. CNS spectrums 21(4): 310–317. DOI: 10.1017/S1092852915000760.

EFIC (2014) Selected reports from the 8th European Pain Congress; Pain in Europe VIII. Journal of Pain and Palliative Care Pharmacotherapy 28(1): 56–69. DOI: 10.3109/15360288.2013.879250.

Fayaz

Croft

Langford

, et al. (2016) Prevalence of chronic pain in the UK: A systematic review and meta-analysis of population studies, BMJ Open 6(6): e010364. DOI: 10.1136/bmjopen-2015-010364.

Hadi

Alldred

Briggs

, et al. (2017) ‘Treated as a number, not treated as a person': A qualitative exploration of the perceived barriers to effective pain management of patients with chronic pain. BMJ Open 7(6): e016454. DOI: 10.1136/bmjopen-2017-016454.

Harvey-Sullivan

Higginbottom

Round

(2022) NICE chronic primary pain guidelines: What the busy GP needs to know. British Journal General Practice 72(718): 240–241. DOI: 10.3399/bjgp22x719453.

IASP (2012) Unrelieved pain is a major global healthcare problem. Available at: www.ethimedix.com/wp-content/uploads/2016/02/Unrelieved-Pain-is-a-Major-Global-Health-Care-Problem.pdf (accessed 7 July 2023).

10.

IASP (2023) Terminology. Available at: www.iasp-pain.org/resources/terminology/#pain (accessed 7 July 2023).

11.

Kang

Trewern

Jackman

, et al. (2023) Chronic pain: Definitions and diagnosis. British Medical Journal 381: e076036. DOI: 10.1136/bmj-2023-076036.

12.

Kmietowicz

(2021) Doctors raise concerns about NICE guidelines on chronic primary pain. British Medical Journal 373: n942. DOI: 10.1136/bmj.n942.

13.

Korwisi

Barke

Kharko

, et al. (2021) Not really nice: A commentary on the recent version of NICE guidelines [NG193: Chronic pain (primary and secondary) in over 16s: Assessment of all chronic pain and management of chronic primary pain] by the Pain Net. Pain Reports 6(4): e961. DOI: 10.1097/pr9.0000000000000961

14.

Lipman

(2009) Pain as a human right. Journal of Pain & Palliative Care Pharmacotherapy 19(3): 85–100. DOI: 10.1080/J354v19n03_16.

15.

NICE (2021) Chronic pain (primary and secondary) in over 16s: Assessment of all chronic pain and management of chronic primary pain. Available at: www.nice.org.uk/guidance/ng193/resources/chronic-pain-primary-and-secondary-in-over-16s-assessment-of-all-chronic-pain-and-management-of-chronic-primary-pain-pdf-66142080468421 (accessed 7 July 2023).

16.

Nicholas

Vlaeyen

Rief

, et al. (2019) The IASP classification of chronic pain for ICD-11: Chronic primary pain. Pain 160(1): 28–37. DOI: 10.1097/j.pain.0000000000001390.

17.

Price

Williams

Smith

, et al. (2019) The National Pain Audit for specialist pain services in England and Wales 2010-2014. British Journal of Pain 13(3): 185–193. DOI: 10.1177/2049463718814277.

18.

Rahman A, Underwood M, et al. (2014) Fibromyalgia. BMJ 348: g1224. DOI: 10.1136/bmj.g1224.

19.

Raja

Carr

Cohen

, et al. (2020) The revised International Association for the Study of Pain definition of pain: Concepts, challenges, and compromises. Pain 161(9): 1976–1982. DOI: 10.1097/j.pain.0000000000001939.

20.

RCGP (2021) Statement of clarification on the latest NICE chronic pain guidance; regarding patients already on medication. Available at: www.rcgp.org.uk/news/latest-nice-chronic-pain-guidance (accessed 3 August 2023).

21.

Rief

Kaasa

Jensen

, et al. (2012) New proposals for the International Classification of Diseases-11 revision of pain diagnoses. Journal of Pain 13(4): 305–316. DOI: 10.1016/j.jpain.2012.01.004.

22.

SIGN (2019) Management of chronic pain: A national clinical guideline [revised edition]. Available at: www.sign.ac.uk/our-guidelines/management-of-chronic-pain (accessed 3 August 2023).

23.

Smith

Colvin

Donaldson-Bruce

, et al. (2021) Drugs for chronic pain: We still need them. British Journal of General Practice 71(705): 172. DOI: 10.3399/bjgp21X715457

24.

Smith

Fors

Korwisi

, et al. (2019) The IASP classification of chronic pain for ICD-11: Applicability in primary care. Pain 160(1): 83–87. DOI: 10.1097/j.pain.0000000000001360.

25.

Stannard

Bernstein

(2021) NICE guideline NG193 for chronic pain: Reasons to be cheerful. British Journal of General Practice 71(712): 489–490. DOI: 10.3399/bjgp21X717425.

26.

The British Pain Society (2021) The British Pain Society's initial statement on NICE guideline NG193 on chronic pain (primary and secondary) in over 16s: Assessment of all chronic pain and management of chronic primary pain. Available at: www.britishpainsociety.org/static/uploads/resources/files/BPS_statement_on_final_NICE_guideline_NG193_for_CPP_and_CSP_-_8_April_2021_FINAL.pdf (accessed 21 December 2022).

27.

Treede

Rief

Barke

, et al. (2019) Chronic pain as a symptom or a disease: The IASP Classification of Chronic Pain for the International Classification of Diseases (ICD-11). Pain 160(1): 19–27. DOI: 10.1097/j.pain.0000000000001384.

28.

Tsang

Von Korff

Lee

, et al. (2008) Common chronic pain conditions in developed and developing countries: Gender and age differences and comorbidity with depression-anxiety disorders. Journal of Pain 9(10): 883–891. DOI: 10.1016/j.jpain.2008.05.005.

29.

Turk

Okifuji

(2002) Psychological factors in chronic pain: Evolution and revolution. Journal of Consulting and Clinical Psychology 70(3): 678–690. DOI: 10.1037//0022-006x.70.3.678.

30.

Upshur

Luckmann

Savageau

(2006) Primary care provider concerns about management of chronic pain in community clinic populations. Journal of General Internal Medicine 21(6): 652–655. DOI: 10.1111/j.1525-1497.2006.00412.x

31.

Vos

(2017) Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries. 1990-2016: A systematic analysis for the Global Burden of Disease Study 2016. Lancet 390(10100): 1211–1259. DOI: 10.1016/S0140-6736(17)32154-2.

32.

WHO (2022) WHO’s new International Classification of Diseases (ICD-11) comes into effect. Available at: www.who.int/news/item/11-02-2022-who-s-new-international-classification-of-diseases-(icd-11)-comes-into-effect (accessed 7 July 2023).