Summary

Chronic pain is a common condition with significant impact on patients' functional ability, mood and quality of life. The economic burden of chronic pain is also severe due to the cost of healthcare utilisation, litigation and compensation claims, social welfare benefits and loss of productivity. Chronic pain is now recognised as a multifaceted condition that includes physical, psychological, social and spiritual dimensions. Over the last decade, the focus of chronic pain and its management has shifted from primarily a biomedical to a biopsychosocial approach. In many patients, pain persists despite treatment of physical cause or when physical cause is absent. Patients with chronic pain are often frustrated, have low self-efficacy and are depressed as the result of their persistent pain, failed treatments, physical disability and associated abnormal psychosocial effects. They develop pain behaviour such as fear avoidance and catastrophise their pain leading to inactivity and physical disability. A pain management programme embracing an integrated cognitive-behavioural therapy and exercise approach has been shown to be effective in improving the outcome in patients with chronic pain. Family physicians play an important role in identifying "yellow flags", initiating early intervention and maintaining patients' adherence to treatment.

摘要

慢性疼痛很常見，它對病人的功能能力、情緒和生活質量有很大影響。由於所需醫療服務的費用、訴訟、賠償、社會福利支出和生產力的損失，慢性疼痛也造成嚴重的經濟負擔。慢性疼痛現在被公認為是一種包括軀體、心理、社會和精神的多因素疾病。在過去十年中，慢性疼痛治療重點已經從生物醫學模式轉為生物—心理—社會模式。許多病人即使經過治療，或已無軀體病因時，疼痛卻依然存在。慢性疼痛的病人，因為持續的疼痛、治療失敗、軀體殘疾以及所引發的心理社會不良反應，常常有挫折感，自覺能力低下和感到抑鬱。病人會產生疼痛行為，如因為怕疼而避免活動（fear avoidance）和將疼痛災難化（catastrophise the pain），從而導致病人不運動和身體殘疾。整合了認知行為療法和鍛鍊方法的疼痛管理計劃，可以有效地改善慢性疼痛病人的結果。家庭醫生在發現疾病信號、施行早期干預和幫助病人堅持治療方面，起著重要的作用。

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Introduction

Chronic pain is defined as pain persisting for longer than three months. It is a common condition in adults with a median prevalence of 15% (2-40%) worldwide.¹ A recent survey reported a similar prevalence of chronic pain of 10.8% in Hong Kong.²

The economic burden of chronic pain is a significant issue in many countries. To put this in perspective, Liu et al estimated that the total annual cost of all coronary heart disease related burdens in the United Kingdom in 1999 was US$13 billion.³ In comparison, Maniadakis and Gray estimated that the total economic burden of back pain alone in the United Kingdom amounted to over US$22 billion in 1998.⁴ In the Netherlands, the cost of neck pain was estimated to be US$686 million in 1996,⁵ while in the United States, the cost of chronic pain was estimated to be US$40 billion a year.⁶ The cost of healthcare utilisation including visits to medical practitioners, medications and other treatment, related compensation claims, social welfare benefits and the loss of productivity contributed to much of this problem.

In the Hong Kong survey, 20% of employed respondents who complained of pain took an average of five days off work during the 12 months prior to the survey.² Of these respondents, 38% complained that their work was affected while over 70% stated that the pain had interfered with their daily life. In addition, 26.5% of chronic pain sufferers were jobless at the time of interview. Another local survey also found that about 37% of patients attending a pain management clinic were unemployed.⁷ In this report, the authors found that 28% of their patients either had completed or have ongoing compensation claims for persistent pain and associated disability resulting from work-place injury, while 31% were either receiving comprehensive social security assistance or disability allowance. About 38% of patients had tried four or more different treatments for their pain conditions.⁷ Chronic pain appears to be a costly medical condition locally as well, and these findings mirror the epidemiology of chronic pain in western populations.^8,9 This paper aims to highlight the multi-dimensional aspects of chronic pain and provides an outline of management strategies for these difficult conditions.

Psychosocial impact of chronic pain

Chronic pain is increasingly recognised as a major health problem at both individual and societal level. Surveys in many countries have repeatedly reported strong associations between chronic pain, psychological distress and interference in daily activities.^10,11 Others have found that depression, anxiety, physical disability and social dysfunction commonly co-exist with chronic pain and affect quality of life.^12-14 Becker and colleagues found that 58% of patients with chronic non-malignant pain in Denmark had either depression or anxiety.¹⁴ In a local survey of chronic pain patients, it was found that 75.3% of Chinese patients with chronic pain have either anxiety or depression.¹⁵ When compared to the local Chinese population norm, the health-related quality of life using the medical outcome survey  Short Form 36 questionnaire, was severely impaired in this group. It is common that people with chronic pain also suffer disproportionately from depression. The quality of life in these patients was also severely affected when compared to the normal population. Development of depression in chronic pain patients often occurs when there is a perceived impact of pain, and a decline in self-control.^16,17

Patients with chronic pain are often frustrated and have low self-efficacy as the result of their persistent pain, physical disability and associated abnormal psychosocial effects.^18,19 Many patients are also frustrated with their unsatisfactory diagnosis and the lack of success with their treatment. In addition, some patients catastrophise and over-emphasise their pain, while others are fearful of the consequence of further injury from movement and activity. Patients who catastrophise tend to focus their pain on all aspects of their life, creating a significant barrier to improvement in both physical and psychological functions. Fear-avoidance in patients with persistent pain leads to inactivity, muscle deconditioning and joint stiffness which further reinforce the fear and disability.²⁰

Chronic pain is a complex and challenging health problem which includes multiple dimensions such as injury management, disability, depression, loss of employment productivity, family disruption, healthcare usage and drug dependence. The concept of pain has shifted from the biomedical to a biopsychosocial model over the last decade. The onion ring model (Figure 1) explained that although pain is a nociceptive event, persistent pain leads to suffering and subsequent behaviours that are shaped by external psychosocial and other environmental factors.²¹ Often this will lead to mood disturbances, social dysfunction and other disabilities. Not surprisingly, there is no simple treatment or single intervention that will resolve all these problems. However, some principles are available to assist in the management of chronic pain conditions.

Diagnosis

Despite numerous clinical evaluations and investigations, the diagnosis and cause of chronic pain remain unclear in many cases. While most physicians are concerned that they have excluded all serious diagnoses, it must be recognised that there is a risk of promoting excessive disability and passivity in the patient who is investigated endlessly and probably fruitlessly.²² Medical training often teaches the doctor to make a diagnosis and prescribe the appropriate treatment to cure the medical condition. It is therefore not surprising that the doctor may feel inadequate when confronted with a chronic pain patient whose investigation results have all come back negative, and the patient has not responded to treatment. Often the doctor will feel compelled to do something for the patient because it implies failure if nothing else can be offered to the patient.

Undoubtedly it is essential to rule out physical factors ("red flags"). Detection of "red flags" indicates the need for more biomedical investigation to exclude correctable conditions. However, psychological and environmental issues are often the causes of disability and distress in patients with chronic pain.²³ The presence of psychological factors or "yellow flags" indicates that the management should be redirected to the cognitive and behavioural aspects²⁴ (Table 1). Both "red and yellow flags" may coexist and their evaluation should lead to appropriate management. When "red flags" have been treated or excluded, the focus in managing the persistent pain should be directed to the "yellow flags".

Chronic pain management: a change in focus

Traditionally, medical practitioners treat pain with pharmacological agents or procedures such as injections and nerve blocks that usually offer some temporary reduction in pain severity. However this relief is almost never complete or long lasting.²⁵ Although the use of strong analgesics and nerve blocks are appropriate and offers effective pain relief in acute postoperative, trauma or cancer pain, they are not as effective in the long-term management of chronic pain. Often this leads to frustration in both the patient and physician in trying to find a cure for the chronic pain.

In these cases, the patients have to accept that there is no clear diagnosis or cure for chronic pain. However, their fear of a missed diagnosis or progressive damage at the area of pain must be clarified and dispelled. They should be made aware that the distress from the pain and the resulting behaviours are often generated and maintained by various psychological and environmental factors. If medical treatment is not successful, then patients should focus on how to self-manage instead of trying to cure the pain condition, so that they can live a more productive and satisfying life.

Multi-disciplinary pain management programme

A multi-disciplinary pain management programme is a rehabilitation programme where the physical, biopsychosocial and environmental aspects of chronic pain are targeted. It often involves contribution from clinical psychologist, physiotherapist, occupational therapist, nurse, social worker and pain medicine physician. Overseas, these programmes have been effective in improving the functional and psychological outcomes in patients with chronic pain (see below). Pain management programmes may be conducted in the inpatient or outpatient setting, with 2-3 weeks of contact time. They are different from conventional physical rehabilitation programmes as they focus on solutions to improve function, mood and overall quality of life. In these programmes, the cognitive-behavioural component is significant and is integrated into the physical rehabilitation.

Few integrated multi-disciplinary pain management programmes are currently available in public hospitals in Hong Kong. The multi-disciplinary pain management programmes at the Alice Ho Miu Ling Nethersole Hospital and Haven of Hope Hospital have been running for over two years. A shorter programme is available at the Queen Mary Hospital. Other types of chronic disease self-management programmes have also recently been available in Hong Kong. These programmes focus on the participants' self-efficacy and confidence to allow them to take control of their chronic disease. They are much shorter programmes compared to a pain management programme, and have less of the physical retraining that is often necessary in patients who may have suffered from persistent pain for many months or years.

One of the objectives of a multi-disciplinary approach in a pain management programme is to teach the participants a new set of coping behaviours to improve their daily functioning without focusing on reducing their pain.²⁶ Information and education improve patients' knowledge about pain and its effect, and facilitate adjustment to their persistent pain. Pain management programmes are often conducted in groups that allow patients to learn from each other's experience. In addition, group interaction offers patients the benefit of mutual support and encouragement from each other, all who have similar conditions and who are in the same situation. A pain management programme helps patients to take a more "active" role in learning to understand, share and manage their pain problems by decreasing their sense of helplessness and improving their self-efficacy in facing their unrelenting pain. The multi-dimensional nature of chronic pain that often comprises both physiological and psychosocial influences, require a strategy of multidisciplinary intervention. This approach teaches the patient how to deal with the multiple problems associated with chronic pain, and caters for the multi-faceted needs of these patients. However, not all patients will require this type of therapy. Patients who have prolonged pain history, complicated by significant pain behaviours are likely to benefit from these programmes.

The cognitive-behavioural approach

One of the most often used therapeutic framework in multidisciplinary pain management programmes is the cognitive-behavioural approach.²⁷ In cognitive-behavioural therapy (CBT), emphasis is placed on recognising the role of psychosocial factors that are associated with the pain experience including sensation, affect, cognition, behaviour and disabilities resulting from chronic pain. CBT aims to reduce the negative impact of these factors and to modify patients' behavioural responses to pain so that they are able to gain a sense of control over the effects of chronic pain on their lives. This strategy teaches patients to live a more functional and satisfying life despite their persistent pain. By improving the patients' self-efficacy, physical function and mood, the patients are able to do more with greater self-confidence and may eventually get back to work. Patients who self-manage their pain condition satisfactorily will decrease their reliance on the healthcare system and medications.

Various cognitive and behavioural coping skills like goal setting, activities pacing, thought challenging, distractions, focusing, coping statements, applied relaxation and assertiveness training are taught to the patients to increase their personal repertoire in dealing with their pain and related problems. Using these techniques, patients practise how to change their maladaptive thoughts (e.g. catastrophising, self-blame) and behaviours (e.g. fear avoidance) toward chronic pain to more adaptive ones. They learn how to handle setback and relapse in their pain problems and to avoid falling into the chronic pain cycle again. The aim is to help patients regain a sense of control over their problems and not to swing toward helplessness and hopelessness about their pain.

In an integrated pain management programme, CBT is conducted together with an intensive physical exercise programme. The exercise programme is linked to restoration of function and as a means to applying coping strategies. The participants are put in control of setting their own physical tolerance and goals so that they are responsible for their activities. The aim is to change the participants' beliefs about physical activities. Graded exposure to movement and feared activities is planned to desensitise the fear of re-injury, while gradual muscle conditioning, strengthening and aerobic exercises improve physical ability and range of functional activities. Individualised occupational retraining is also introduced during the programme to facilitate future work rehabilitation. At the same time, participants are also taught how to reduce and manage their pain relief medications.

An evidence-based treatment

Meta-analysis and systematic reviews have shown that multi-disciplinary pain management programmes involving a cognitive-behavioural approach are effective in improving patients' function, mood, sleep and quality of life.^28-30 These studies found that chronic pain management using a cognitive-behavioural approach was more effective than no active intervention. Flor et al found substantial improvements in activity level, pain intensity, pain behaviours, use of medication and health service in patients who attended multidisciplinary pain management programmes.²⁸ These patients were twice as likely to return to work than patients with no treatment. In a systematic review involving chronic pain patients, the authors found that intensive multi-disciplinary biopsychosocial rehabilitation improved pain and functional outcomes compared to usual care or outpatient non-multidisciplinary approach.²⁹ However, there were mixed results in vocational outcomes such as work readiness and sick leaves. Another meta-analysis also showed significant improvement in pain experience, cognitive coping and reduced behavioural expression of pain.³⁰ A further systematic review of patients with chronic back pain by van Tulder, found strong evidence of improvement in pain relief, functional status, and behavioural outcomes in patients who received a pain management programme compared to waiting-list controls or those who did not have any treatment.³¹

Other randomised controlled studies have shown that the cognitive-behavioural approach to managing chronic pain also improves self-efficacy beliefs, use of active coping strategies, functional ability, medication usage,³² activity level, catastrophising and pain behaviours, sick leave level and relieves affective distress.^33,34 These improvements were maintained over a long period. Clearly there is an enormous amount of evidence that indicates that the psychological and cognitive-behavioural management approach is more effective in managing the difficult and complex chronic pain patients as compared to treating these patients with medications or injections.

Role of family physicians

Family physicians have the appropriate setting and training to deal with chronic pain patients. They are trained in counselling, and have the strong rapport with their patients and their family members which often instils trust and confidence in them. The privacy of the clinic setting also offers a non-threatening environment for the patient. Family physicians have a role in identifying the presence of these "yellow flags" and in initiating early appropriate management.^24,35

Although the primary care setting in Hong Kong is not well developed, family physician-led chronic pain management is possible. There may be concerns that chronic pain management is difficult and often fraught with failures, thereby leading to doctor-shopping and unwillingness of patients to see the same family physician again, thus making continuity of care impossible. Outcome related to commonly practised biomedical-based management with an aim for a cure is certainly doomed to fail. However, with the alternative biopsychosocial management approach aiming to improve function and quality of life, but not pain, patients often improve their relationship with their physician simply because they are more likely to achieve an improvement that may boost their self efficacy.

Time constraint in a busy practice may hinder the ability of the family physician to manage this type of patient, as some time may be required for counselling and therapy. However, the duration of treatment may be flexible and span over several weeks or months. Two to three sessions of 15 to 30 minutes duration each week may be required initially and then adjusted to less frequently as progress is made. The aims are to change the patients' mind-set about their pain condition, and to teach them how to manage their flare-ups and set-backs. Employing the principles of prioritising, planning and pacing and problem solving exercises allow patients to develop their repertoire of coping strategies for different situations (Table 2).

In some patients with chronic pain, an integrated multi-disciplinary pain management programme may be necessary. Even in these patients, family physicians represent an integral part of such programme. They should be involved in identifying the appropriate patients and referring them to the relevant pain management programme. Early evaluation of patients from primary care with back and neck pain has been shown to be a good predictor of future absenteeism due to sickness and recovery of function, using a specific screening questionnaire.³⁶ For those patients who have just completed the pain management programme, their family physicians should continue to provide support to the patient, reinforce and ensure that coping strategies are being used appropriately, monitor progress and manage the patients' medications. The involvement of referring family physicians have been reported to improve treatment adherence.³⁷

Conclusion

Chronic pain is an enormous burden to the community. It is often difficult to treat and affects patients' functional ability, mood and overall quality of life. It is also a significant economic burden affecting healthcare utilisation, decreased productivity in the work-force, increased litigation and compensation claims as well as public social welfare benefits. A pain management programme embracing an integrated cognitive-behavioural therapy and exercise approach has been shown to be effective in improving the outcome of patients with chronic pain. Family physicians play an important role in identifying "yellow flags" and initiating early intervention.

Key messages

1. Chronic pain is a complex multi-dimensional disorder that is often difficult to treat.
2. Chronic pain affects patients functional ability, mood and overall quality of life resulting in increased healthcare utilisation, decreased productivity in the workforce, increased litigation and compensation claims as well as social welfare benefits.
3. Multi-disciplinary pain management programme embracing an integrated cognitive-behavioural therapy and exercise approach is effective in improving the outcome of patients with chronic pain.
4. Family physicians have a role in identifying the presence of "yellow flags" and initiating early appropriate management.
5. For difficult patients who required multi-disciplinary pain management programme, family physicians should continue to provide support to the patient after the programme, reinforce and ensure that coping strategies are being used appropriately, monitor progress and manage the patients' medications.

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References