Adolescent chronic pain and disability: A review of the current evidence in assessment and treatment

Abstract

Adolescents who suffer from chronic pain also report complex syndrome-associated disability and distress that can detrimentally affect the quality of their lives and the lives of their family members. Over the past 10 years, there have been significant developments in both methods of assessment and in treatment programs. There have also been good developments in clinical assessment tools, although many need further study. However, the evidence base of available treatments remains small, and there is an urgent need for new trials in both pharmacological and nonpharmacological treatments. The greatest challenges are organizational, and the concern is how to bring patients in contact with available treatments. Many patients who could benefit from evidence-supported treatments are not currently able to access treatment. Theoretical developments aimed at explaining chronic pain within the context of the family, as well as family attempts at coping with complex disability, are underway.

Adolescents report chronic pain with a similar prevalence and incidence as adults (1). Although pain has been under-recognized and undertreated (2), we are now beginning to respond to the needs of adolescents and their families, who report unmanaged pain, disability and distress. The challenge is to bring evidence in support of local practice and to guide the development of services for adolescents and their families struggling to cope with pain. In the present paper, we briefly summarize the research evidence on the impact of pain, introduce methods of assessment, review the current evidence base for chronic pain management and discuss current developments in treatment. We offer only an introduction to this field, seeking to raise awareness and guide further investigation.

THE IMPACT OF CHRONIC PAIN

There are few studies on the prevalence of pain reported by young people. An early review paper (3) cited the prevalence of medically unexplained chronic pain to be approximately 15% for children and adolescents. A recent large-scale Dutch study (1) has reported a greater estimate of 25%. Some features are repeated across most epidemiological- and clinical-based studies. First, girls report more severe pain, and they report it more frequently than boys (4). Second, the most common type of pain in childhood is headache. In the Dutch study, for example, headache was the most common complaint at 23%, followed by abdominal pain (22%) and limb pain (22%) (1). Third, older children report pain more frequently than younger children.

Chronic pain can have a widespread impact on many aspects of life (5). Although pain is, by definition, unpleasant, aversive and distracting, the majority of children who report pain do not show extensive distress and disability. For example, although the Dutch study reported that as many as 8% of their large sample reported episodes of severe pain, the sample was a school-attending population and, at the very least, the pain did not lead to absenteeism, one proxy of disability. Similarly, in a more recent study, Roth-Isigkeit et al (6) reported only 3.5% of children in daily pain.

A minority does, however, report disability and distress associated with chronic pain. In clinic-attending populations, there is a typical pattern of disability associated with depression and maladaptive coping that is more pronounced in younger age groups (7,8). Greater anxiety is also a common feature of the chronic pain presentation, typically anxiety about pain and its consequences (9). Overall, young people report a significantly reduced ability to engage in normal activities of childhood, including school, play and sleep (6,10).

Family functioning is also commonly affected. In particular, parents of adolescents with chronic pain report significant distress and changes in their roles. In one study, the authors (11) reported high levels of significant anxiety and depression suffered by parents, as well as stress in the actual tasks of parenting a child with pain (12), which was associated with the younger age of the child and the greater depression suffered by the child. In a qualitative study of this theme, the authors found evidence for a style of parenting more appropriate to a younger child. More specifically, parents discussed a sense that they were treating their adolescent as they would a dependent preteenager.

Chronic pain is not only costly to the psychological and physical health of the family, but also to their financial health. In one cost of illness study in the United Kingdom (13), overall direct and indirect costs of chronic pain were calculated for a sample of 52 families with one son or daughter with chronic pain. Direct costs included all health care costs for both the adolescent and the family members (due to the child’s chronic pain), and indirect costs captured wider costs to the family such as loss of earnings and out of pocket expenses (such as adaptations to houses, over-the-counter medications and home help). The overall annual cost to a household living with a child in chronic pain was £4495 (approximately CAD$10,400) for those with a diagnosis of juvenile rheumatoid arthritis and £14,160 (approximately CAD$32,750) for those with idiopathic chronic pain.

In short, chronic pain can have widespread and severely negative consequences for the child and their family members. A clinical picture emerges from these data of adolescents with repetitive episodes of disabling persistent pain that can destroy their quality of life and may leave them depressed and anxious about the meaning of their pain and about their future. Parents struggle to makes sense of their child’s pain and what the most appropriate response should be, over time becoming depressed and spending effort and money searching for a curative solution (13–15).

ASSESSMENT OF CHRONIC PAIN

Pain is a subjective experience for which the gold standard of measurement remains either self-report, or observation when self-report is impossible or is compromised. Two recent authoritative reviews on the use of measurement technology for the assessment of pain are available, one behavioural (16) and one self-report (17). There is a number of quick, simple and developmentally appropriate measurement tools for use in both community and hospital settings. In addition to the measurement of pain itself, the authors have argued that an attempt should be made to measure the impact of pain in its broader context.

In a review of all measures that had been used in studies of adolescent chronic pain (including those cited above), the authors reviewed the content of 43 separate instruments (18). Most studies had attempted to use instruments more suited to adults with chronic pain, or for mental health problems in adolescents. There remains a need to develop measurement technology sensitive and relevant to the needs of adolescents with chronic pain. There are, however, some instruments that are psychometrically validated and have a track record, in particular for the measurement of function (eg, the Functional Disability Inventory [19] and the Child Activity Limitations Interview [20]).

Recently, the authors developed a multidimensional instrument designed to capture the impact of chronic pain on a range of domains of outcome. The aim of the Bath Adolescent Pain Questionnaire was to provide a single instrument with broad coverage. The Bath Adolescent Pain Questionnaire is a 61-item measurement, with content capturing experience in seven related domains: social functioning, physical functioning, depression, general anxiety, pain-specific anxiety, family functioning and social development. The instrument has good reliability and validity for each of its subscales, and has performed well with both an idiopathic chronic pain sample and a juvenile rheumatoid arthritis sample (21). Further psychometric investigations will be necessary to demonstrate its utility.

The inclusion of a subscale designed to measure social development was an interesting and speculative addition to this measure, given that there is no literature on the impact of chronic pain on development. However, because of the urging of the paediatric pain community to consider the developmental context of their assessment and management strategies (22), it was judged appropriate to attempt a method of assessing social development. The method selected was one of self-report of comparative social development. Patients are asked to compare themselves to their peers and to make a judgment about their own development. This subscale falls easily into three factors: independence, identity formation and emotional management. In all cases, teenagers with chronic pain thought that chronic pain had detrimentally affected their development compared with their peers.

EVIDENCE-BASED CHRONIC PAIN MANAGEMENT

Applying evidence to paediatric practice brings particular challenges; many of the treatments available are based on data extrapolated from the adult literature. There is some evidence for the use of acetaminophen or ibuprofen for childhood headache (23,24). A systematic review of pharmacotherapy for recurrent abdominal pain has found some support for famotidine, pizotifen and peppermint oil enteric-coated capsules (25). For young people with idiopathic musculoskeletal or neuropathic pain syndromes such as fibromyalgia or chronic regional pain syndrome type 1 (CRPS1), the use of tricyclic antidepressant and anticonvulsant medications have been used, but the authors know of no controlled trials to guide use.

There is an established evidence base on psychological therapies for chronic pain. In particular, in the well-developed field of headache, biofeedback and relaxation technologies are traditionally used (26). The Cochrane Collaboration systematic review of randomized controlled trials of psychosocial interventions reports that 18 trials were found to meet the criteria for inclusion in a review, 13 with analyzable data (27). Most of the trials were for simple interventions for recurrent headache, and the findings were positive. In fact, the number needed to treat for psychological therapies producing 50% pain relief in child and adolescent headache is 2.32, which compares very favourably with other numbers needed to treat in all treatments of adult chronic pain (28).

Four of the trials reviewed in this analysis were from the same Scandinavian research group and were focused on brief relaxation-based interventions, delivered by nonpsychologists (typically school nurses) in community settings. They demonstrate that for the most common childhood pain problem (tension type headache), there are effective, safe and inexpensive solutions in school-nurse administered relaxation training. For frequent tension headache and migraine, therapist-delivered therapy was more effective (29). The barriers to implementation of these highly successful pain management strategies are predominantly social and organizational, not medical.

Not covered in the systematic review is the emerging literature on multimodal, multicomponent or interdisciplinary interventions that are developing to focus not only on pain but on wider aspects of suffering. There are a number of examples of these programs internationally. An excellent example is the program of physical therapy (PT) and psychological therapy, developed in Boston for adolescents with CRPS1. High-dose PT with psychological support was more effective than low-dose PT with psychological support in reducing disability in a population of early diagnosed patients (30). A more intensive and multidisciplinary example is well established in Philadelphia (31). There are two European examples of detailed programs. Data from Dusseldorf/Datteln, Germany, of a multidisciplinary approach with a mixed chronic pain sample showed good outcomes in the quality of life that are sustained at 12-month follow-up (32). The Bath Pain Management Unit in the United Kingdom delivers an interdisciplinary program of cognitive behaviour therapy, working with adolescents and their parents (33). Evaluation data show not only good subjective outcomes sustained at three months, but also excellent return to school rates (34).

ISSUES IN CURRENT MANAGEMENT

Research into chronic pain management has developed healthily over the past 10 years, but there remain significant challenges in assessment, treatment and theoretical development to be confronted.

Assessment is the foundation of good clinical management, and there has been a tendency to underestimate and under-report the extent and impact of chronic pain. Missing is an accepted system of classification of disability and suffering associated with chronic pain. Where this has been developed with adults, it has proved useful (35); a similar system for adolescent chronic pain would be helpful for both epidemiological and clinical research.

Treatment challenges are twofold. First, further clinical trials are necessary to establish the effectiveness of treatments for chronic pain. Although there is some evidence (eg, relaxation for tension type headache), it is merely an oasis of knowledge in a desert of ignorance. Second, it is interesting to reflect that where there is strong evidence for a treatment, its use is uncommon. One of the major challenges for the paediatric community is to bring patients into contact with treatments. To speculate, perhaps some of the developments in treatment go against standard organizational practice in health care. For example, the high intensity physiotherapy for CRPS1 is heavily reliant on effective community surveillance to identify patients within the first month; psychosocial treatments for headache requires psychologists to work in a training capacity in the community; and the provision of interdisciplinary rehabilitation requires a model of working with dyads of both children and parents.

Theoretically, we need to know why some children develop frequent pain that disrupts their everyday life (eg, recurrent abdominal pain) and why some children develop a syndrome of treatment-resistant disability and distress associated with their chronic pain. The emotional reactions, in particular the heightened fear about pain and disability, are emerging as particularly important in explaining disability. However, it is not only the emotional behaviour of patients that matters but also the emotional behaviour of parents. Parents struggling to make sense of the experience of their children in pain play a crucial role in determining the approach to pain management, and in shaping future child-coping behaviour.