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Interdisciplinary pain management with pain patients: evidence for its effectiveness
Seminars in Pain Medicine Vol. 1 No. 2 2003
Interdisciplinary Pain Management With Pain Patients: Evidence for Its Effectiveness AKIKO OKIFUJI, PhD
ABSTRACT Chronic pain is a prevalent and debilitating condition and can become quite recalcitrant. Poor outcomes from traditional medical, pharmacological, and surgical approaches have been an impetus to development of comprehensive pain programs (CPPs) in which pain specialists from multiple disciplines provide treatment for patients. With health-care costs continuing to rise, the clinical efficacy and costeffectiveness of CPPs have been of greatly increased interest. In this study, evidence supporting the efficacy of CPP treatment for chronic pain is reviewed on the basis of multiple criteria. I also discuss additional treatment parameters (patient characteristics, treatment delivery, process variables) in considering the efficacy of CPPs. The literature generally supports positive results for CPPs for the various parameters. Furthermore, CPPs are likely to produce long-term cost-savings in health-care expenditures and indemnity costs. Key words: chronic pain, interdisciplinary pain management, treatment effectiveness.
accredited by the Commission on Accreditation of Rehabilitation Facilities (CARF), which has standards that are specifically designated for pain programs offering interdisciplinary pain management care. There are several terms describing pain treatment programs involving clinicians from multiple disciplines. To provide some consistency in characterizing pain treatment facilities, the International Association for the Study of Pain4 described four classes (Table 1). The term further evolved to introduce the “interdisciplinary” pain care. Generally, the multidisciplinary and interdisciplinary pain centers are defined as: “An organization of health care professionals and basic and applied scientists that includes research, teaching, and patient care related to acute
Specialized pain clinics began to proliferate shortly after the conclusion of the World War II. These clinics were unimodal in focus, providing mostly nerve blocks and regional anesthesia for a range of pain disorders. It did not take long for clinicians to recognize the limitation of the unimodal pain medicine practice for complex pain syndromes. This realization has prompted other medical and health-care professionals to enter into the field of pain medicine, marking the development of a team approach to manage complex pain problems. In 1977, the Committee on Pain Therapy of the American Society of Anesthesiologists listed a total of 327 pain clinics in their Directory of Pain Clinics.1 By 1990, Bonica2 estimated there were approximately 1000 pain treatment clinics in the USA alone. Today, there are approximately 3800 pain programs, clinics, centers, and solo practices in the USA,3 up from 3411 and 2356 estimated in 1997 and 1995, respectively. It has been estimated that almost 8 million Americans received pain management from pain clinics, centers, and solo practitioners in 2002.3 According to a recently published report,3 there are approximately 443 “accredited” pain management programs, clinics, and centers in the USA. Of these, 143 facilities are
From the Pain Research and Management Center, Department of Anesthesiology, University of Utah, Salt Lake City, Utah. Supported in part by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (R01 AR43606). Address reprint requests to: Akiko Okifuji, PhD, Pain Research and Management Center, Department of Anesthesiology, University of Utah, 615 Arapeen Drive, Ste. 200, Salt Lake City, UT 84108. Email: [email protected]. © 2003 Elsevier Inc. All rights reserved. 1537-5897/03/0102-0000/$30.00/0 doi:10.1016/S1537-5897(03)00025-9
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Table 1. Classification of Pain Center Modality-Oriented Clinic: Offers a specific type of treatment, but does not provide comprehensive assessment or management. It has no emphasis on an integrated, comprehensive team approach. The clinic may not be pain-specific, but rather is defined by a single modality in which the clinic is specialized (e.g., massage therapy, acupuncture). Pain Clinic: Focuses on diagnosis and management of patients with chronic pain and may specialize in the assessment and treatment of specific pain diagnosis (e.g., back pain, headaches). Multidisciplinary Pain Clinic: Staffed by a team of clinicians including physicians of different specialties and other health-care providers who specialize in the diagnosis and management of chronic pain. It does not include research and teaching activities in its regular program. Multidisciplinary Pain Center: Includes a range of health-care professional specialized in pain diagnosis and management, such as physicians, psychologists, nurses, physical therapists, occupational therapists, and other specialty care providers. The primary clinical approach is an integrated multimodal approach. It is generally affliated with a major health science institution and has research and teaching activities as a part of its regular operations. Modified from Loeser.4
and chronic pain. It includes a wide array of health care professionals including physicians, psychologists, nurses, physical therapists (PTs), occupational therapists (OTs), and other specialty health care providers. Multiple therapeutic modalities are available. These centers provide evaluation and treatment and are usually affiliated with major health science institutions‘5 (pp. 18-19). Conventional wisdom, however, treats the two terms as somewhat distinctive. The basic concept that facilitated introduction of the term “interdisciplinary” aimed to emphasize the importance of synthesized, integrated care across multiple disciplines, implying that “multidisciplinary” would mean only that a patient receive care from providers in a different discipline. If we are to be more meticulous about the definition, the two terms may be differentiated as: Multidisciplinary ⫽ Sum (Medicine ⫹ Psychology ⫹ Physical Therapy ⫹ Nursing ⫹ etc.) Interdisciplinary ⬎ Sum (Medicine ⫹ Psychology ⫹ Physical Therapy ⫹ Nursing ⫹ etc.) with the idea being that interdisciplinary pain management offers greater therapeutic effects from the integration of care than does multidisciplinary pain care. However, there are no standard rules or criteria in practice that clearly delineate the distinctive features of the two terms. Thus, we frequently find that the two terms are used more or less interchangeably in the literature. There are also additional terms, such as biopsychosocial rehabilitation, functional restoration, and behaviorally oriented programs, that include services from multiple domains.
The primary purpose of this article is to discuss the current status of evidence supporting interdisciplinary pain management for pain patients. To minimize the aforementioned confusion regarding these terms, I review the literature evaluating comprehensive pain treatment programs involving a team of disciplines aiming at improved pain management and functional restoration. For the sake of simplicity, I call these programs comprehensive pain programs (CPPs).
Patient Characteristics There is an ubiquitous assumption that all chronic pain patients are akin and comparable to one another. Empirical evidence, however, indicates that patients who are referred to CPPs represent a unique group from the chronic pain population at large, and that we need to recognize that the populations served by CPPs are not representative of chronic pain patients. Many patients have generally undergone multiple treatments with no success by the time they receive a referral to CPPs. The meta-analysis of 65 outcome studies on CPPs, including a total of 3089 patients, report that patients coming to CPPs have an average pain duration of 7 years, with over half of these patients having had at least one surgery.6 In addition, evidence suggests that CPP patients tend to suffer from greater functional disability and emotional distress. The prevalence of depression, for example, is about 50% in the tertiary CPP population,7 whereas it ranges from 6% to 10% among pain patients seeking treatment at HMO clinics.8 The epidemiology investigating the patient characteristics indicates that chronic pain patients who are referred to CPPs stand out with regard to the following characteristics:9,10
112 Seminars in Pain Medicine Vol. 1 No. 2 June 2003 ● ● ● ● ● ● ●
Greater functional impairment. More likely to have constant pain. Greater level of emotional distress. Greater health-care utilization. More likely to use opioid analgesics. Higher prevalence of work-related injuries as pain onset. Higher prevalence of past surgical interventions.
When we evaluate the effectiveness of a CPP approach, we must understand that the evidence is based on treatment outcomes from the most recalcitrant group of patients.
Treatment Delivery In the early years of CPPs, inpatient pain programs were the standard mode of CPP delivery. Patients were hospitalized for 4 to 8 weeks or longer, and underwent a structured set of daily treatments. Over the years, however, financial pressures developed. Clearly, the cost associated with inpatient pain programs is substantially greater than with outpatient programs. The change of climate in the health-care system has driven most inpatient pain programs to shift toward day-treatment or outpatient programs. Another issue potentially contributing to the shift in the delivery mode concerns the generalizability of clinical benefit from the inpatient pain program to patients’ daily lives. Inpatient programs exercise greater control over the patient’s life during their stay. Acquisition and practice of their rehabilitative skills and coping efforts are performed in the environment relatively free from their daily stressors and contexts that compromise patients’ rehabilitative efforts. Some patients may find the transition difficult from the well-controlled hospital environment to their own natural habitat without the opportunity to actively practice the learned skills in their natural habitat. There have been several studies addressing the clinical effect of mode of treatment delivery in chronic pain patients. The earlier study11 demonstrated greater benefit following an inpatient program compared with their outpatient program. Both programs were 3 weeks long; although the total number of therapy hours for each program was not reported, the report implied that the inpatient program required many more therapy hours than the outpatient program. The modalities of the program were mostly physical therapy and education. A comparison demonstrated that the inpatient program resulted in superior effects compared with the outpatient program by the end of treatment, but patients
in both groups relapsed during long-term follow-up, thereby eliminating the group difference. Subsequently, a series of studies comparing the clinical benefit of inpatient and outpatient pain programs for low back pain showed superior effects for inpatient CPP at posttreatment as well as during long-term follow-up.12,13 Similarly, Williams et al.14 demonstrated that their 4-week inpatient CPP resulted in greater benefit in physical and psychological functioning than did the 8-week (one-half day per week) outpatient program, even though the contents of both therapeutic programs were equivalent. On the other hand, several studies15-17 concluded that outpatient CPP programs would be as effective as inpatient programs, and that the former would be more cost-effective because they offered significant cost savings. The opposite end of the treatment-delivery approach from a structured inpatient program is a fieldtreatment program, such as an extended “homebased” treatment program in which supervised paraprofessionals visit patients at home to provide CPP care. Home-based programs are less structured, although acquisition and practice of self-management skills in the home environment may enhance the generalizability of clinical benefit. Cott et al.18 demonstrated that significantly increased improvement in the functional status of patients in a homebased program compared with an office-based treatment program. Further research is clearly needed to better understand the effectiveness of different delivery modes, but we also need to delineate a set of specific factors for patient–treatment matching. It is reasonable to assume that some patients benefit greatly from intensive programs, whereas others may achieve significant improvement with less intensive, outpatient programs. From the service perspective, it is important to understand the components of each delivery mode necessary to produce clinical benefit. Moreover, it is equally important to examine patient characteristics that result in greater clinical effectiveness with certain treatment modalities and delivery. The heterogeneity in the nature of CPP and patient populations in the chronic pain literature likely contribute to the conflicting results in clinical outcome studies. This area of interest is discussed later in this study.
Process Variables The concept of measuring process variables originated from industry’s effort to ensure quality in manufacturing.19 In our field of health-care research, pro-
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cess refers to the quality of the implementation of therapy, or “how well the treatment in question is provided.” The process variables are extremely important in assuring the validity of an outcome study through prevention, detection, and early remediation for inappropriate actions. In pain medicine, such process variables include treatment compliance, treatment delivery mode, and resource allocation. Treatment compliance is an important factor in evaluating CPPs. Rehabilitative effort requires patients’ active participation in the program. Compliance with the prescribed regimen in all areas of the CPP program is essential for successful outcome. Many patients who are deactivated and deconditioned often find activating physical therapy, for example, terrifyingly hard to perform. Noncompliance with exercise is common and detrimental to the outcomes of CPPs.20 Furthermore, when negative outcome results are found, the absence of compliance data makes it impossible to determine whether poor outcome resulted from the inefficacious treatment modality or whether the method of delivery was poorly executed. Similarly, the evaluation of CPPs is complicated by the large variability in the “ingredients” of their programs. Each discipline has a range of therapeutic regimens. In psychology alone, some programs may offer mostly didactic, psychoeducational sessions, whereas others include active skills training. One of the important factors in assessing the effectiveness of the program is to evaluate treatment validity. For example, validity evaluation should ascertain whether improvement in cognitive factors (e.g., less negative, more empowered) follows the implementation of cognitive therapy. An active exercise program should improve the physical capacity of the patients at the end of the treatment. Separate analyses of these two concepts are necessary to understand the mechanisms of the treatment and to troubleshoot in case of treatment failure. Such efforts will help facilitate better integration of outcomes research across studies.
Outcome Criteria The literature is confusing partly because of the diversity and inconsistency of outcome criteria across studies. Therapeutic goals for CPPs are generally multifaceted. Among the most common are goals aimed to: ● ● ●
Reduce pain. Improve function. Permit return to work.
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Resolve medication issues. Reduce health-care utilization. Resolve disability claims.
The importance of these items is relative, depending mostly upon what party is asked. Patients at the time of evaluation seem to focus on the first two items. On the other hand, many referring physicians may be more concerned about the last item, particularly with regard to the use of opioid analgesics.21 Third-party payers may consider all but health-care utilization as being of little consequence. Pain Reduction and Functions Published reports indicate that CPPs result in varying degrees of pain reduction, ranging from 14%22 to 60%,23 with an average of 20% to 30%.6 Recently, in attempt to delineate evidence for the efficacy of CPPs, a series of systematic reviews were performed for a range of pain disorders, including low back pain, 24 pain associated with upper limb repetitive strain injuries,25 fibromyalgia,26 and neck and shoulder pain.27 These publications reviewed a large number of studies and found that most utilized suboptimal methodology. Guzman et al.24 found only ten randomized, controlled trials (RCTs) adequate for their review, but noted that intensive CPPs with the functional restoration approach were effective in improving function and moderately reducing pain. However, the remaining reviews found only a small number of studies to be eligible for their review, and even these studies were found to be rather poor in their methodological quality. Moreover, the reviews showed only limited efficacy of CPPs. Clinical research to test the efficacy of CPPs is extremely labor-intensive, complicated by the complex logistics involved and large costs incurred. Often it is neither feasible nor ethical to randomize patients into treatment conditions. In general, a large numbers of patients are necessary, because, within-group designs, such as the cross-over approach, are not possible in CPPs, and also because a range of outcome variables must be evaluated, which requires a large sample size to maintain a reasonable level of statistical power. Nonetheless, one must caution against automatically discarding non-RCT studies as inadequate. The effort to maintain balance between adequate randomization and respecting a patient’s right to choose may skew the characteristics of patient sampling in RTCs.28 Comparisons between a program in which patients are randomly assigned and a program in which patients have elected to participate yielded a comparative treatment benefit for both inpatient and
114 Seminars in Pain Medicine Vol. 1 No. 2 June 2003 outpatient cases.29 Although well-controlled RCTs investigating efficacy are of high value, well-designed non-RCT studies may substantially enhance our understanding of the effectiveness of the different treatment modalities. Meta-analysis of 65 outcome studies, involving over 3000 patients, evaluating the effectiveness of CPPs indicates that CPPs reduce pain significantly by the end of the treatment. Similarly, patients who undergo CPPs showed significantly greater improvement in the level of functional activities than did untreated patients (65% versus 35%). Similar results were obtained in a narrative review of various treatment modalities for treating fibromyalgia.30 Approximately 70% of studies investigating the efficacy CPPs showed improvement in pain, although only 33% of these studies demonstrated a reduction in hyperalgesic response to induced pain. This discrepancy illustrates the importance of measuring multiple outcomes because treatment differentially affects each aspect of the clinical pain syndromes.
Return to Work Evaluation of return to work is extremely complex. Studies have varied on how work is defined (e.g., full-time, part-time, training). Return to work is generally operationalized as a cross-sectional factor; thus, timing parameters (e.g., how long should a person maintain the work, when the question should be asked) determine the positive counts. What such an assessment generally lacks is information regarding whether patients continue to work once they return. A number of factors influence return to work in chronic pain patients, including: (a) physical demands of the job; (b) regional variation in the job market; (c) availability of job accommodations; (d) marketability of patients’ skills; (e) extent of wage replacement; and (f) financial incentives. Finding an employer may be particularly difficult for patients with a long history of chronic pain and job skills predicated on high degrees of physical exertion. Consider, for example, a case of a job applicant with a long history of back pain and associated disability: For consideration for a job requiring physical labor, this person is likely to receive less preferential consideration than a candidate with no history of previous disability associated with back pain. Furthermore, not only are patients much older than they were at the onset of their pain problems (7 years, on average6), but also years of unemployment could result in a considerable mismatch between the patient’s job skills and skills required for today’s
Table 2. Return to Work Rates Studies Roberts et al.57 Sturgis et al.58 Guck et al.59 Finlyson et al.60 Duckro et al.61 Mayer et al.62 Tollison et al.63 Hazard et al.64 Saches et al.65 Deardorff et al.66 Tollison 35 Feuerstein et al.67 Tyre et al.68 Bendix et al.69 Hiderbrandt et al.70 Pfingsten et al.71 Vendrig et al.72
CPP
Control
77 29 75 65 71 87 56 81 63 48 57 74 86 64 62 63 65
5 14 25 44 33 41 27 29 42 0 20 40 NA 29 NA NA NA
NA, not available.
jobs. Depreciation of job skills may also be accelerated by rapid advancements in technologies. Thus, the difficulties in regaining employment may arise from the lack of opportunity for CPP patients to acquire job skills needed for today’s job market due to long-term unemployment. In light of the multiple factors adversely affecting the chances of patients to be employed it is unsuprising that, if untreated, only 25% of patients return to work.6 Table 2 summarizes results from recent clinical studies assessing return to work following completion of a CPP. Return-to-work rates after a CPP are shown to range from 29% to 86%, with a mean of 64.5%. On the other hand, consistently lower rates, from 0% to 42%, with a mean rate of 25.5%, are shown for non-CPP patients. Health-Care Utilization and Medication Issues As noted earlier, chronic pain is a costly condition and the costs of health care continue to rise. Our group31,32 has emphasized the importance of incorporating health-care utilization data as a part of the treatment outcome. Treatment of persistent pain is labor-intensive and expensive, and thus we need to demonstrate that CPPs are a viable option as well as being economically sensible, particularly in light of the general and pervasive belief that CPPs are expensive and not cost-effective, especially among thirdparty payers. Costs for MPC treatment vary depending upon the setting and level of intensity. One estimate for the average outpatient MPC rehabilitation program was $5075.3 Health-care utilization data from CPP trials have generally yielded favorable results. One study found a greater than 33% reduction in pain-related clinic
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visits in an HMO setting in the year after completion of a CPP that had a strong cognitive-behavioral orientation.33 Several reports23,34 obtained similar results, with a substantial decline in medical care for back pain CPP completion. Polypharmacy is not uncommon in chronic pain patients, particularly among those with comorbid conditions and in elderly patients. According to a recent estimate, the sales of analgesics in the USA approximated $8 billion in 2000, and this figure is expected to grow by 10% annually.3 Research considering reduction in medication use has traditionally focused on the use of opioid analgesics. The use of opioids for noncancer chronic pain patients remains a controversial issue. The nature of the debate is beyond the scope of this study; however, reduction, or elimination, of opioid medications has traditionally been a part of the clinical outcome for research investigating the effectiveness of CPPs. Approximately 50% of patients take opioid analgesics at the time of an initial evaluation in CPPs.6 Following CPP treatment, over 65% of these patients were found to discontinue their opioid medications for at least 1 year.23 Subsequently, Tollison35 reported striking results when comparing opioid use between patients who completed a CPP and patients who were not able to participate in the program due to denial from their payers. The former group showed a significant reduction in opioid use from 69% at the admission to 22% at 1-year follow-up, whereas, in the latter group, opioid use was reduced only slightly, from 81% to 75%. These data are not intended to dispute the appropriateness of use of opioid analgesics for noncancer chronic pain patients. However, the results are rather telling when combined with significant pain reduction and improvement in function. From the healthcare economy perspective, it seems to make sense that helping patients become more efficient in selfmanagement of their pain and disability would decrease their reliance on the health-care system.
Disability Claims Many individuals with chronic pain problems find it difficult to maintain employment and begin to rely on disability benefits. A recent report36 estimated that up to $43 billion is spent annually in the USA for disability compensation for back pain alone. Similar to the return-to-work criterion and health-care utilization, whether CPP treatment leads to the termination of disability claims has become an important outcome due to the socioeconomic implications
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of reduced productivity, wage loss, and disability payments. A substantial number of CPP-treated patients seem to terminate their disability claims after completing treatment. In one study the proportion of patients receiving disability was significantly reduced, from 70% to 45%.37 For example, approximately 75% of cases are recommended for termination,38 and most of the litigation is settled within 1 year.39 Unfortunately, the clinical effects of the conventional and surgical interventions on terminating disability claims have not been studied and remain unknown. A cautionary note is worth mentioning with regard to the implications of the findings on claim terminations. The decision as to whether a claim should be terminated is essentially administrative, not clinical. In an ideal situation, the decision should be based on signs and symptoms that are objectively measured. However, claim termination for chronic pain patients must, given the subjective nature of the syndrome, depend upon patients’ self-reports of pain and disability. The complex nature of chronic pain disorders inevitably makes the extent and quality of the claim adjusters very important. Nonetheless, very little is known about the reliability of decisionmaking by case managers on closing disability claims. In addition, societal and organizational pressures to promote closures may also become relevant as financial resources become more constricted. Therefore, careful interpretation is needed to understand disability closure as a treatment outcome in pain therapy. Economic Evaluation Cost containment in the managed health-care environment has increased the importance of establishing economic advantages of therapeutic interventions. Two types of analytic methods to evaluate economic consequences of interventions are cost– benefit analysis and cost-effective analysis. The two terms are often mislabeled and are frequently used interchangeably. The confusion in the current literature in the economic analysis of health-care delivery seems to result largely from confusion in the definition and the use of these terms. Definitions Both cost– benefit and cost-effective analyses are methods to compare the relationships between cost and clinical outcomes across different interventions. The two methods, however, differ in the expressions of effectiveness.
116 Seminars in Pain Medicine Vol. 1 No. 2 June 2003 Table 3. Index of Cost-Effectiveness for Chronic Pain: CPP versus conventional medication management versus surgical intervention Treatment CPP Conventional Surgical
Cost of treatment
Improvement
Index
$8,100 $26,000 $15,000
67% 24% 43%
0.83 0.09 0.29
Cost– benefit analysis evaluates the costs and effects of the intervention in a same, usually monetary, unit. Standardization of the unit used has an advantage because it permits comparisons across dissimilar intervention programs. On the other hand, conversion of treatment effects to a monetary unit may not always be feasible. In a cost-effective analysis, treatment outcomes are measured by criteria other than monetary terms, such as lives saved or return to work. The cost-tooutcome ratio can be estimated, and comparisons can be made between any interventions using ratios with common denominators. In a series of reports, our group31,32,40,41 demonstrated striking results of cost savings by CPPs. In a cost-effective analysis, we may ask questions about whether the treatment in question is, relative to an alternative modality42: ● ● ● ●
More effective at the same cost. At least as effective and less costly. More effective at a higher cost, but the benefit exceeds the added cost. Less effective at a lower cost, but the added benefit of alternative treatment is not worth the added cost.
One estimate,41 based on the available cost data for various health-care services, provided a figure for substantial savings in health-care expenditure of approximately $8500 per person per year, after taking the treatment cost for CPPs into consideration. The mean age of patients referred to CPPs is 45 years; the average American lives to 77 years of age.43 Thus, the average savings in a CPP can be estimated to be $272,000 per person, without accounting for increases in health-care costs over time. In an attempt to evaluate the relative cost-effectiveness of CPPs relative to standard care and surgical intervention, our group41 has also delineated an index score for cost-effectiveness, using return-to-work data as the outcome point. This index was defined as the ratio of improvement over the cost of treatment (Table 3; costs of treatment based on the data reported in the referred report). The larger the index score, the greater the level of cost-effectiveness. Based
on these figures, one may conclude that CPPs result in substantially increased cost-effectiveness in helping chronic pain patients return to work, compared with conventional medical and surgical interventions. These results are striking if one considers the patient characteristics of CPPs, discussed earlier in this study. CPPs tend to treat those patients who have not responded to conventional medical and surgical intervention.
Future Directions Heterogeneity of Chronic Pain Patients In evaluating treatment outcomes, we tend to divide patients into groups based on the primary pain diagnoses (e.g., back, headaches, fibromyalgia), considered one group sharing common features and mechanisms. This practice inevitably results in the assumption that all patients should respond similarly to a single set of CPP treatment. Given the multifactorial nature of chronic pain problems, it is reasonable to assume that patients’ clinical needs are multifaceted, with varying degrees of needs and aptitudes in each dimension. For example, research has demonstrated that chronic pain patients are quite diverse in their psychosocial characteristics.44-46 Treating such diverse needs with one set of treatment is likely to compromise the effectiveness of the treatment. Indeed, studies indicate that patients with various psychosocial characteristics respond differently to a single treatment.47-49 These results suggest that, because CPP treatment generally includes a wide range of treatment components, combinations of CPP components may be packaged differently to match patients’ clinical characteristics. Thus, future research should be asking the question of not only whether CPPs are effective, but also of what treatments should be delivered to patients in what way with what characteristics.50
Prevention Considering the adverse impact of chronic pain on patients’ lives and the society at large, preventive interventions have been of great interest in recent years. Prevention may be primary, in which attempts are made to prevent initial injury that may become chronically troublesome, or may be secondary, involving early intervention at the time of the initial injury. Recent reviews51,52 have pointed out that evaluations of single modalities, such as education, ex-
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ercise, ergometrics, and risk factor (e.g., smoking) modifications, have yielded inconsistent results in preventing back pain. These modalities, however, may work more beneficially if administered in an integrated fashion. There is some evidence that some combinations of exercise and educational programs may help to reduce wage loss and medical costs53; however, the contributions of multidisciplinary work on prevention of chronic pain are not presently well understood. Because a history of back pain is one of the predictors of future back problems,54 secondary prevention programs could be incorporated in CPPs. Such programs would require less intensive effort when compared with rehabilitative programs treating chronic back pain, which were reviewed in this study. The preventive programs may incorporate education, body mechanics, exercise, and psychosocial interventions, particularly with regard to reduction of a pain-contingent lifestyle and modifications of risk factors with a strong focus on returning to usual activities as quickly as possible. Prospective studies are needed to evaluate the efficacy of CPPs in the secondary prevention of disability associated with chronic pain.
Conclusions Growing constraints on health-care resources has forced us to become more explicit about the accountability and evidence-based treatment outcomes in determining choice of treatment. Unfortunately, the common misperception of CPPs as being ineffective and costly seems to persist, particularly from the perspective of third-party payers. This is ironic because the literature suggests that CPP treatments are probably the most rigorously tested modality in the area of chronic pain.55 Because various biopsychosocial factors are involved in chronic pain, such as physical conditioning, operant, respondent, social learning, emotional, and cognitive factors, it is reasonable to conclude that interactions among clinicians with expertise from various disciplines would be most helpful. Reflecting this philosophical stance, outcome evaluations of CPP treatments generally provide empirical support for their effectiveness. However, CPP trials are often criticized for their methodological weaknesses. The majority of outcome studies are excluded from the Cochrane reviews for this reason. One of the problems in testing CPPs is that the conventional scientific methodology is often inapplicable in clinical trials for CPPs due to ethical concerns and the complexity of the treatment plans. Innovative thinking that goes beyond conventional RCTs is needed to improve the methodologi-
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cal integrity of CPP trials to demonstrate clinical effectiveness. From the practice point of view, although the multifactorial definition of pain56 has been widely accepted, transition of clinical practice from unimodal treatments of chronic pain to CPPs is, unfortunately, not simple. Many physicians, especially when services in the other disciplines are not easily accessible, are compelled to become a “multidisciplinary team” by themselves. It is unrealistic to ask a single physician to have a detailed understanding of psychology, PT, OT, and nursing at levels sufficient to complete comprehensive assessment and treatment of chronic pain. Nor it is not likely be a cost-effective practice. Therefore, although the consultation–liaison model of practice may have to be adopted in the absence of clinical resources, we must strive to help not only patients but also clinicians and administrators (e.g., hospital, insurance, medical school, and departments in which PTs, OTs, psychologists, and nurses are trained) understand the needs and rationale for developing CPPs. The available literature strongly suggests that CPPs offer promising treatments for chronic pain patients. Furthermore, CPPs have been shown to be more cost-effective relative to surgical and conventional medical interventions. These results are particularly impressive given that many patients have undergone other treatments without achieving satisfactory outcomes and come to CPPs as the last resort. Should those patients be referred early or undergo preventive programs, the clinical effectiveness and cost-effectiveness of CPPs would likely show improvement. It seems reasonable, therefore, to conclude that CPPs offer one of the most vital clinical options for those who suffer from chronic, disabling pain problems.
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back pain: results of treatment at the Pain Therapy Center. South Med J 1985;78(11):1291-1295 Guzman J, Esmail R, Karjalainen K, et al: Multidisciplinary bio-psycho-social rehabilitation for chronic low back pain. Cochrane Database Syst Rev 2002;1 Karjalainen K, Malmivaara A, van Tulder M, et al: Biopsychosocial rehabilitation for upper limb repetitive strain injuries in working age adults. Cochrane Database Syst Rev 2000;3 Karjalainen K, Malmivaara A, van Tulder M, et al: Multidisciplinary rehabilitation for fibromyalgia and musculoskeletal pain in working age adults. Cochrane Database Syst Rev 2000;2 Karjalainen K, Malmivaara A, van Tulder M, et al: Multidisciplinary biopsychosocial rehabilitation for neck and shoulder pain among working age adults. Cochrane Database Syst Rev 2000;3 Silverman WA, Altman DG: Patients’ preferences and randomised trials. Lancet 1996;347(8995):171-174 Williams AC, Nicholas MK, Richardson PH, et al: Generalizing from a controlled trial: the effects of patient preference versus randomization on the outcome of inpatient versus outpatient chronic pain management. Pain 1999;83(1):57-65 Okifuji A, Ashburn M: Fibromyalgia: comprehensive evaluation. Crit Rev Phys Rehabil Med 2001; 13(1):24-54 Okifuji A, Turk D, Kalauokalani D: Clinical outcome and economic evaluation of multidisciplinary pain centers, in Block A, Kremer E, Fernandez E (eds): Handbook of pain syndromes: biopsychosocial perspectives. Mahwah, NJ, Lawrence Erlbaum, 1998 Turk D, Okifuji A: Multidisciplinary approach to pain management: philosophy, operations, and efficacy, in Ashburn M, Rice L (eds): The management of pain. Baltimore, MD, Churchill Livingstone, 1997 Caudill M, Schnable R, Zuttermeister P, et al: Decreased clinic use by chronic pain patients: response to behavioral medicine intervention. Clin J Pain 1991;7(4):305-310 Cairns D, Mooney V, Crane P: Spinal pain rehabilitation: inpatient and outpatient treatment results and development of predictors for outcome. Spine 1984;9(1):91-95 Tollison C: Comprehensive treatment approach for lower back workers’ compensation injuries. J Occup Rehabil 1991;1:281-287 Frymoyer J, Durett C: The economics of spinal disorders, in Frymoyer J (ed): The adult spine, (ed 2). Philadelphia, PA, Lippincott-Raven, 1997 Painter JR, Seres JL, Newman RI: Assessing benefits of the pain center: why some patients regress. Pain 1980;8(1):101-113 Seres JL, Newman RI: Results of treatment of chronic low-back pain at the Portland Pain Center. J Neurosurg 1976;45(1):32-36 Mayer T, Gatchel R, Kishino N, et al: Objective assessment of spine function following industrial
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40.
41.
42.
43. 44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
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injury. A prospective study with comparison group and one-year follow-up. Spine 1985;10:482-493 Turk D, Okifuji A: Multidisciplinary pain centers: boons or boondoggles? J Workers’ Comp 1997;6(4):9-26 Turk D, Okifuji A: Treatment of chronic pain patients: clinical outcome, cost-effectiveness, and costbenefits of multidisciplinary pain centers. Crit Rev Phys Rehabil Med 1998;10:181-208 Doubilet P, Weinstein MC, McNeil BJ: Use and misuse of the term “cost effective” in medicine. N Engl J Med 1986;314(4):253-256 Minino AM, Smith BL: Deaths: preliminary data for 2000. Natl Vital Stat Rep 2001;49(12):1-40 Scharff L, Turk D, Marcus D: Psychosocial and behavioral characteristics in chronic headache patients: support for a continuum and dual-diagnostic approach. Cephalalgia 1995;15(3):216-223 Turk D, Rudy T: The robustness of an empirically derived taxonomy of chronic pain patients. Pain 1990;43(1):27-35 Turk D, Sist T, Okifuji A, et al: Adaptation to metastatic cancer pain, regional/local cancer pain and non-cancer pain: role of psychological and behavioral factors. Pain 1998;74(2):247-256 Turk DC, Okifuji A, Sinclair JD, et al: Differential responses by psychosocial subgroups of fibromyalgia syndrome patients to an interdisciplinary treatment. Arthritis Care Res 1998;11(5):397-404 Turk D, Okifuji A, Sinclair J, et al: Pain, disability, and physical functioning in subgroups of patients with fibromyalgia. J Rheumatol 1996;23(7):1255-1262 Rudy T, Turk D, Kubinski J, et al: Differential treatment responses of TMD patients as a function of psychological characteristics. Pain 1995;61(1):103-112 Turk D: Customizing treatment for chronic pain patients: who, what, and why. Clin J Pain 1990;6: 255-270 Lahad A, Malter AD, Berg AO, et al: The effectiveness of four interventions for the prevention of low back pain. JAMA 1994;272(16):1286-1291 Kaplansky BD, Wei FY, Reecer MV: Prevention strategies for occupational low back pain. Occup Med 1998;13(1):33-45 Ryan WE, Krishna MK, Swanson CE: A prospective study evaluating early rehabilitation in preventing back pain chronicity in mine workers. Spine 1995; 20(4):489-491 Smedley J, Egger P, Cooper C, et al: Prospective cohort study of predictors of incident low back pain in nurses [see comments]. BMJ 1997;314(7089): 1225-1228 Loeser J: The role of pain clinics in managing chronic back pain, in Frymoyer J (ed): The adult spine: principles and practice. New York: NY, Raven Press, 1991 International Association for the Study of Pain: Classification of chronic pain. Descriptions of chronic pain syndromes and definitions of pain terms. Pain 1986;3(suppl 1):S1-226
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57. Roberts AH, Reinhardt L: The behavioral management of chronic pain: long-term follow-up with comparison groups. Pain 1980;8(2):151-162 58. Sturgis ET, Schaefer CA, Sikora TL: Pain center follow-up study of treated and untreated patients. Arch Phys Med Rehabil 1984;65(6):301-303 59. Guck TP, Skultety FM, Meilman PW, et al: Multidisciplinary pain center follow-up study: evaluation with a no-treatment control group. Pain 1985;21(3):295-306 60. Finlayson R, Maruta T, Morse R, et al: Substance dependence and chronic pain: experience with treatment and follow-up results. Pain 1986;26:175-180 61. Duckro P, Margolis R, Tait R, et al: Long-term follow-up of chronic pain patients: a preliminary study. Int J Psychiatry Med 1985;15:283-292 62. Mayer TG, Gatchel RJ, Mayer H, et al: A prospective two-year study of functional restoration in industrial low back injury. An objective assessment procedure (published erratum appears in JAMA 1988; 259(2): 220). JAMA 1987;258(13):1763-1767 63. Tollison C, Kriegel M, Satterthwaite J, et al: Comprehensive pain center treatment of low back workers’ compensation injuries. An industrial medicine clinical outcome follow-up comparison. Orthop Rev 1989;18 64. Hazard RG, Fenwick JW, Kalisch SM, et al: Functional restoration with behavioral support. A oneyear prospective study of patients with chronic lowback pain. Spine 1989;14(2):157-161 65. Sachs B, David J, Olimpio D, et al: Spinal rehabilitation by work tolerance based on objective physical capacity assessment of dysfunction. A prospective study with control subjects and twelve-month review. Spine 1990;15:1325-1332 66. Deardorff WW, Rubin HS, et al: Comprehensive multidisciplinary treatment of chronic pain: a follow-up study of treated and non-treated groups. Pain 1991;45(1):35-43 67. Feuerstein M, Callan-Harris S, Hickey P, et al: Multidisciplinary rehabilitation of chronic work-related upper extremity disorders. Long-term effects. J Occup Med 1993;35(4):396-403 68. Tyre TE, Walworth DE, Tyre EM: The outcome status of chronic pain patients 4 years after multidisciplinary care. Wisc Med J 1994;93(1):9-12 69. Bendix AF, Bendix T, Vaegter K, et al: Multidisciplinary intensive treatment for chronic low back pain: a randomized, prospective study. Cleve Clin J Med 1996;63(1):62-69 70. Hildebrandt J, Pfingsten M, Saur P, et al: Prediction of success from a multidisciplinary treatment program for chronic low back pain. Spine 1997;22(9): 990-1001 71. Pfingsten M, Hildebrandt J, Leibing E, et al: Effectiveness of a multimodal treatment program for chronic low-back pain. Pain 1997;73(1):77-85 72. Vendrig AA, van Akkerveeken PF, McWhorter KR: Results of a multimodal treatment program for patients with chronic symptoms after a whiplash injury of the neck. Spine 2000;25(2):238-244
Interdisciplinary Pain Management With Pain Patients: Evidence for Its Effectiveness AKIKO OKIFUJI, PhD
ABSTRACT Chronic pain is a prevalent and debilitating condition and can become quite recalcitrant. Poor outcomes from traditional medical, pharmacological, and surgical approaches have been an impetus to development of comprehensive pain programs (CPPs) in which pain specialists from multiple disciplines provide treatment for patients. With health-care costs continuing to rise, the clinical efficacy and costeffectiveness of CPPs have been of greatly increased interest. In this study, evidence supporting the efficacy of CPP treatment for chronic pain is reviewed on the basis of multiple criteria. I also discuss additional treatment parameters (patient characteristics, treatment delivery, process variables) in considering the efficacy of CPPs. The literature generally supports positive results for CPPs for the various parameters. Furthermore, CPPs are likely to produce long-term cost-savings in health-care expenditures and indemnity costs. Key words: chronic pain, interdisciplinary pain management, treatment effectiveness.
accredited by the Commission on Accreditation of Rehabilitation Facilities (CARF), which has standards that are specifically designated for pain programs offering interdisciplinary pain management care. There are several terms describing pain treatment programs involving clinicians from multiple disciplines. To provide some consistency in characterizing pain treatment facilities, the International Association for the Study of Pain4 described four classes (Table 1). The term further evolved to introduce the “interdisciplinary” pain care. Generally, the multidisciplinary and interdisciplinary pain centers are defined as: “An organization of health care professionals and basic and applied scientists that includes research, teaching, and patient care related to acute
Specialized pain clinics began to proliferate shortly after the conclusion of the World War II. These clinics were unimodal in focus, providing mostly nerve blocks and regional anesthesia for a range of pain disorders. It did not take long for clinicians to recognize the limitation of the unimodal pain medicine practice for complex pain syndromes. This realization has prompted other medical and health-care professionals to enter into the field of pain medicine, marking the development of a team approach to manage complex pain problems. In 1977, the Committee on Pain Therapy of the American Society of Anesthesiologists listed a total of 327 pain clinics in their Directory of Pain Clinics.1 By 1990, Bonica2 estimated there were approximately 1000 pain treatment clinics in the USA alone. Today, there are approximately 3800 pain programs, clinics, centers, and solo practices in the USA,3 up from 3411 and 2356 estimated in 1997 and 1995, respectively. It has been estimated that almost 8 million Americans received pain management from pain clinics, centers, and solo practitioners in 2002.3 According to a recently published report,3 there are approximately 443 “accredited” pain management programs, clinics, and centers in the USA. Of these, 143 facilities are
From the Pain Research and Management Center, Department of Anesthesiology, University of Utah, Salt Lake City, Utah. Supported in part by grants from the National Institute of Arthritis and Musculoskeletal and Skin Diseases (R01 AR43606). Address reprint requests to: Akiko Okifuji, PhD, Pain Research and Management Center, Department of Anesthesiology, University of Utah, 615 Arapeen Drive, Ste. 200, Salt Lake City, UT 84108. Email: [email protected]. © 2003 Elsevier Inc. All rights reserved. 1537-5897/03/0102-0000/$30.00/0 doi:10.1016/S1537-5897(03)00025-9
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Table 1. Classification of Pain Center Modality-Oriented Clinic: Offers a specific type of treatment, but does not provide comprehensive assessment or management. It has no emphasis on an integrated, comprehensive team approach. The clinic may not be pain-specific, but rather is defined by a single modality in which the clinic is specialized (e.g., massage therapy, acupuncture). Pain Clinic: Focuses on diagnosis and management of patients with chronic pain and may specialize in the assessment and treatment of specific pain diagnosis (e.g., back pain, headaches). Multidisciplinary Pain Clinic: Staffed by a team of clinicians including physicians of different specialties and other health-care providers who specialize in the diagnosis and management of chronic pain. It does not include research and teaching activities in its regular program. Multidisciplinary Pain Center: Includes a range of health-care professional specialized in pain diagnosis and management, such as physicians, psychologists, nurses, physical therapists, occupational therapists, and other specialty care providers. The primary clinical approach is an integrated multimodal approach. It is generally affliated with a major health science institution and has research and teaching activities as a part of its regular operations. Modified from Loeser.4
and chronic pain. It includes a wide array of health care professionals including physicians, psychologists, nurses, physical therapists (PTs), occupational therapists (OTs), and other specialty health care providers. Multiple therapeutic modalities are available. These centers provide evaluation and treatment and are usually affiliated with major health science institutions‘5 (pp. 18-19). Conventional wisdom, however, treats the two terms as somewhat distinctive. The basic concept that facilitated introduction of the term “interdisciplinary” aimed to emphasize the importance of synthesized, integrated care across multiple disciplines, implying that “multidisciplinary” would mean only that a patient receive care from providers in a different discipline. If we are to be more meticulous about the definition, the two terms may be differentiated as: Multidisciplinary ⫽ Sum (Medicine ⫹ Psychology ⫹ Physical Therapy ⫹ Nursing ⫹ etc.) Interdisciplinary ⬎ Sum (Medicine ⫹ Psychology ⫹ Physical Therapy ⫹ Nursing ⫹ etc.) with the idea being that interdisciplinary pain management offers greater therapeutic effects from the integration of care than does multidisciplinary pain care. However, there are no standard rules or criteria in practice that clearly delineate the distinctive features of the two terms. Thus, we frequently find that the two terms are used more or less interchangeably in the literature. There are also additional terms, such as biopsychosocial rehabilitation, functional restoration, and behaviorally oriented programs, that include services from multiple domains.
The primary purpose of this article is to discuss the current status of evidence supporting interdisciplinary pain management for pain patients. To minimize the aforementioned confusion regarding these terms, I review the literature evaluating comprehensive pain treatment programs involving a team of disciplines aiming at improved pain management and functional restoration. For the sake of simplicity, I call these programs comprehensive pain programs (CPPs).
Patient Characteristics There is an ubiquitous assumption that all chronic pain patients are akin and comparable to one another. Empirical evidence, however, indicates that patients who are referred to CPPs represent a unique group from the chronic pain population at large, and that we need to recognize that the populations served by CPPs are not representative of chronic pain patients. Many patients have generally undergone multiple treatments with no success by the time they receive a referral to CPPs. The meta-analysis of 65 outcome studies on CPPs, including a total of 3089 patients, report that patients coming to CPPs have an average pain duration of 7 years, with over half of these patients having had at least one surgery.6 In addition, evidence suggests that CPP patients tend to suffer from greater functional disability and emotional distress. The prevalence of depression, for example, is about 50% in the tertiary CPP population,7 whereas it ranges from 6% to 10% among pain patients seeking treatment at HMO clinics.8 The epidemiology investigating the patient characteristics indicates that chronic pain patients who are referred to CPPs stand out with regard to the following characteristics:9,10
112 Seminars in Pain Medicine Vol. 1 No. 2 June 2003 ● ● ● ● ● ● ●
Greater functional impairment. More likely to have constant pain. Greater level of emotional distress. Greater health-care utilization. More likely to use opioid analgesics. Higher prevalence of work-related injuries as pain onset. Higher prevalence of past surgical interventions.
When we evaluate the effectiveness of a CPP approach, we must understand that the evidence is based on treatment outcomes from the most recalcitrant group of patients.
Treatment Delivery In the early years of CPPs, inpatient pain programs were the standard mode of CPP delivery. Patients were hospitalized for 4 to 8 weeks or longer, and underwent a structured set of daily treatments. Over the years, however, financial pressures developed. Clearly, the cost associated with inpatient pain programs is substantially greater than with outpatient programs. The change of climate in the health-care system has driven most inpatient pain programs to shift toward day-treatment or outpatient programs. Another issue potentially contributing to the shift in the delivery mode concerns the generalizability of clinical benefit from the inpatient pain program to patients’ daily lives. Inpatient programs exercise greater control over the patient’s life during their stay. Acquisition and practice of their rehabilitative skills and coping efforts are performed in the environment relatively free from their daily stressors and contexts that compromise patients’ rehabilitative efforts. Some patients may find the transition difficult from the well-controlled hospital environment to their own natural habitat without the opportunity to actively practice the learned skills in their natural habitat. There have been several studies addressing the clinical effect of mode of treatment delivery in chronic pain patients. The earlier study11 demonstrated greater benefit following an inpatient program compared with their outpatient program. Both programs were 3 weeks long; although the total number of therapy hours for each program was not reported, the report implied that the inpatient program required many more therapy hours than the outpatient program. The modalities of the program were mostly physical therapy and education. A comparison demonstrated that the inpatient program resulted in superior effects compared with the outpatient program by the end of treatment, but patients
in both groups relapsed during long-term follow-up, thereby eliminating the group difference. Subsequently, a series of studies comparing the clinical benefit of inpatient and outpatient pain programs for low back pain showed superior effects for inpatient CPP at posttreatment as well as during long-term follow-up.12,13 Similarly, Williams et al.14 demonstrated that their 4-week inpatient CPP resulted in greater benefit in physical and psychological functioning than did the 8-week (one-half day per week) outpatient program, even though the contents of both therapeutic programs were equivalent. On the other hand, several studies15-17 concluded that outpatient CPP programs would be as effective as inpatient programs, and that the former would be more cost-effective because they offered significant cost savings. The opposite end of the treatment-delivery approach from a structured inpatient program is a fieldtreatment program, such as an extended “homebased” treatment program in which supervised paraprofessionals visit patients at home to provide CPP care. Home-based programs are less structured, although acquisition and practice of self-management skills in the home environment may enhance the generalizability of clinical benefit. Cott et al.18 demonstrated that significantly increased improvement in the functional status of patients in a homebased program compared with an office-based treatment program. Further research is clearly needed to better understand the effectiveness of different delivery modes, but we also need to delineate a set of specific factors for patient–treatment matching. It is reasonable to assume that some patients benefit greatly from intensive programs, whereas others may achieve significant improvement with less intensive, outpatient programs. From the service perspective, it is important to understand the components of each delivery mode necessary to produce clinical benefit. Moreover, it is equally important to examine patient characteristics that result in greater clinical effectiveness with certain treatment modalities and delivery. The heterogeneity in the nature of CPP and patient populations in the chronic pain literature likely contribute to the conflicting results in clinical outcome studies. This area of interest is discussed later in this study.
Process Variables The concept of measuring process variables originated from industry’s effort to ensure quality in manufacturing.19 In our field of health-care research, pro-
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cess refers to the quality of the implementation of therapy, or “how well the treatment in question is provided.” The process variables are extremely important in assuring the validity of an outcome study through prevention, detection, and early remediation for inappropriate actions. In pain medicine, such process variables include treatment compliance, treatment delivery mode, and resource allocation. Treatment compliance is an important factor in evaluating CPPs. Rehabilitative effort requires patients’ active participation in the program. Compliance with the prescribed regimen in all areas of the CPP program is essential for successful outcome. Many patients who are deactivated and deconditioned often find activating physical therapy, for example, terrifyingly hard to perform. Noncompliance with exercise is common and detrimental to the outcomes of CPPs.20 Furthermore, when negative outcome results are found, the absence of compliance data makes it impossible to determine whether poor outcome resulted from the inefficacious treatment modality or whether the method of delivery was poorly executed. Similarly, the evaluation of CPPs is complicated by the large variability in the “ingredients” of their programs. Each discipline has a range of therapeutic regimens. In psychology alone, some programs may offer mostly didactic, psychoeducational sessions, whereas others include active skills training. One of the important factors in assessing the effectiveness of the program is to evaluate treatment validity. For example, validity evaluation should ascertain whether improvement in cognitive factors (e.g., less negative, more empowered) follows the implementation of cognitive therapy. An active exercise program should improve the physical capacity of the patients at the end of the treatment. Separate analyses of these two concepts are necessary to understand the mechanisms of the treatment and to troubleshoot in case of treatment failure. Such efforts will help facilitate better integration of outcomes research across studies.
Outcome Criteria The literature is confusing partly because of the diversity and inconsistency of outcome criteria across studies. Therapeutic goals for CPPs are generally multifaceted. Among the most common are goals aimed to: ● ● ●
Reduce pain. Improve function. Permit return to work.
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Resolve medication issues. Reduce health-care utilization. Resolve disability claims.
The importance of these items is relative, depending mostly upon what party is asked. Patients at the time of evaluation seem to focus on the first two items. On the other hand, many referring physicians may be more concerned about the last item, particularly with regard to the use of opioid analgesics.21 Third-party payers may consider all but health-care utilization as being of little consequence. Pain Reduction and Functions Published reports indicate that CPPs result in varying degrees of pain reduction, ranging from 14%22 to 60%,23 with an average of 20% to 30%.6 Recently, in attempt to delineate evidence for the efficacy of CPPs, a series of systematic reviews were performed for a range of pain disorders, including low back pain, 24 pain associated with upper limb repetitive strain injuries,25 fibromyalgia,26 and neck and shoulder pain.27 These publications reviewed a large number of studies and found that most utilized suboptimal methodology. Guzman et al.24 found only ten randomized, controlled trials (RCTs) adequate for their review, but noted that intensive CPPs with the functional restoration approach were effective in improving function and moderately reducing pain. However, the remaining reviews found only a small number of studies to be eligible for their review, and even these studies were found to be rather poor in their methodological quality. Moreover, the reviews showed only limited efficacy of CPPs. Clinical research to test the efficacy of CPPs is extremely labor-intensive, complicated by the complex logistics involved and large costs incurred. Often it is neither feasible nor ethical to randomize patients into treatment conditions. In general, a large numbers of patients are necessary, because, within-group designs, such as the cross-over approach, are not possible in CPPs, and also because a range of outcome variables must be evaluated, which requires a large sample size to maintain a reasonable level of statistical power. Nonetheless, one must caution against automatically discarding non-RCT studies as inadequate. The effort to maintain balance between adequate randomization and respecting a patient’s right to choose may skew the characteristics of patient sampling in RTCs.28 Comparisons between a program in which patients are randomly assigned and a program in which patients have elected to participate yielded a comparative treatment benefit for both inpatient and
114 Seminars in Pain Medicine Vol. 1 No. 2 June 2003 outpatient cases.29 Although well-controlled RCTs investigating efficacy are of high value, well-designed non-RCT studies may substantially enhance our understanding of the effectiveness of the different treatment modalities. Meta-analysis of 65 outcome studies, involving over 3000 patients, evaluating the effectiveness of CPPs indicates that CPPs reduce pain significantly by the end of the treatment. Similarly, patients who undergo CPPs showed significantly greater improvement in the level of functional activities than did untreated patients (65% versus 35%). Similar results were obtained in a narrative review of various treatment modalities for treating fibromyalgia.30 Approximately 70% of studies investigating the efficacy CPPs showed improvement in pain, although only 33% of these studies demonstrated a reduction in hyperalgesic response to induced pain. This discrepancy illustrates the importance of measuring multiple outcomes because treatment differentially affects each aspect of the clinical pain syndromes.
Return to Work Evaluation of return to work is extremely complex. Studies have varied on how work is defined (e.g., full-time, part-time, training). Return to work is generally operationalized as a cross-sectional factor; thus, timing parameters (e.g., how long should a person maintain the work, when the question should be asked) determine the positive counts. What such an assessment generally lacks is information regarding whether patients continue to work once they return. A number of factors influence return to work in chronic pain patients, including: (a) physical demands of the job; (b) regional variation in the job market; (c) availability of job accommodations; (d) marketability of patients’ skills; (e) extent of wage replacement; and (f) financial incentives. Finding an employer may be particularly difficult for patients with a long history of chronic pain and job skills predicated on high degrees of physical exertion. Consider, for example, a case of a job applicant with a long history of back pain and associated disability: For consideration for a job requiring physical labor, this person is likely to receive less preferential consideration than a candidate with no history of previous disability associated with back pain. Furthermore, not only are patients much older than they were at the onset of their pain problems (7 years, on average6), but also years of unemployment could result in a considerable mismatch between the patient’s job skills and skills required for today’s
Table 2. Return to Work Rates Studies Roberts et al.57 Sturgis et al.58 Guck et al.59 Finlyson et al.60 Duckro et al.61 Mayer et al.62 Tollison et al.63 Hazard et al.64 Saches et al.65 Deardorff et al.66 Tollison 35 Feuerstein et al.67 Tyre et al.68 Bendix et al.69 Hiderbrandt et al.70 Pfingsten et al.71 Vendrig et al.72
CPP
Control
77 29 75 65 71 87 56 81 63 48 57 74 86 64 62 63 65
5 14 25 44 33 41 27 29 42 0 20 40 NA 29 NA NA NA
NA, not available.
jobs. Depreciation of job skills may also be accelerated by rapid advancements in technologies. Thus, the difficulties in regaining employment may arise from the lack of opportunity for CPP patients to acquire job skills needed for today’s job market due to long-term unemployment. In light of the multiple factors adversely affecting the chances of patients to be employed it is unsuprising that, if untreated, only 25% of patients return to work.6 Table 2 summarizes results from recent clinical studies assessing return to work following completion of a CPP. Return-to-work rates after a CPP are shown to range from 29% to 86%, with a mean of 64.5%. On the other hand, consistently lower rates, from 0% to 42%, with a mean rate of 25.5%, are shown for non-CPP patients. Health-Care Utilization and Medication Issues As noted earlier, chronic pain is a costly condition and the costs of health care continue to rise. Our group31,32 has emphasized the importance of incorporating health-care utilization data as a part of the treatment outcome. Treatment of persistent pain is labor-intensive and expensive, and thus we need to demonstrate that CPPs are a viable option as well as being economically sensible, particularly in light of the general and pervasive belief that CPPs are expensive and not cost-effective, especially among thirdparty payers. Costs for MPC treatment vary depending upon the setting and level of intensity. One estimate for the average outpatient MPC rehabilitation program was $5075.3 Health-care utilization data from CPP trials have generally yielded favorable results. One study found a greater than 33% reduction in pain-related clinic
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visits in an HMO setting in the year after completion of a CPP that had a strong cognitive-behavioral orientation.33 Several reports23,34 obtained similar results, with a substantial decline in medical care for back pain CPP completion. Polypharmacy is not uncommon in chronic pain patients, particularly among those with comorbid conditions and in elderly patients. According to a recent estimate, the sales of analgesics in the USA approximated $8 billion in 2000, and this figure is expected to grow by 10% annually.3 Research considering reduction in medication use has traditionally focused on the use of opioid analgesics. The use of opioids for noncancer chronic pain patients remains a controversial issue. The nature of the debate is beyond the scope of this study; however, reduction, or elimination, of opioid medications has traditionally been a part of the clinical outcome for research investigating the effectiveness of CPPs. Approximately 50% of patients take opioid analgesics at the time of an initial evaluation in CPPs.6 Following CPP treatment, over 65% of these patients were found to discontinue their opioid medications for at least 1 year.23 Subsequently, Tollison35 reported striking results when comparing opioid use between patients who completed a CPP and patients who were not able to participate in the program due to denial from their payers. The former group showed a significant reduction in opioid use from 69% at the admission to 22% at 1-year follow-up, whereas, in the latter group, opioid use was reduced only slightly, from 81% to 75%. These data are not intended to dispute the appropriateness of use of opioid analgesics for noncancer chronic pain patients. However, the results are rather telling when combined with significant pain reduction and improvement in function. From the healthcare economy perspective, it seems to make sense that helping patients become more efficient in selfmanagement of their pain and disability would decrease their reliance on the health-care system.
Disability Claims Many individuals with chronic pain problems find it difficult to maintain employment and begin to rely on disability benefits. A recent report36 estimated that up to $43 billion is spent annually in the USA for disability compensation for back pain alone. Similar to the return-to-work criterion and health-care utilization, whether CPP treatment leads to the termination of disability claims has become an important outcome due to the socioeconomic implications
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of reduced productivity, wage loss, and disability payments. A substantial number of CPP-treated patients seem to terminate their disability claims after completing treatment. In one study the proportion of patients receiving disability was significantly reduced, from 70% to 45%.37 For example, approximately 75% of cases are recommended for termination,38 and most of the litigation is settled within 1 year.39 Unfortunately, the clinical effects of the conventional and surgical interventions on terminating disability claims have not been studied and remain unknown. A cautionary note is worth mentioning with regard to the implications of the findings on claim terminations. The decision as to whether a claim should be terminated is essentially administrative, not clinical. In an ideal situation, the decision should be based on signs and symptoms that are objectively measured. However, claim termination for chronic pain patients must, given the subjective nature of the syndrome, depend upon patients’ self-reports of pain and disability. The complex nature of chronic pain disorders inevitably makes the extent and quality of the claim adjusters very important. Nonetheless, very little is known about the reliability of decisionmaking by case managers on closing disability claims. In addition, societal and organizational pressures to promote closures may also become relevant as financial resources become more constricted. Therefore, careful interpretation is needed to understand disability closure as a treatment outcome in pain therapy. Economic Evaluation Cost containment in the managed health-care environment has increased the importance of establishing economic advantages of therapeutic interventions. Two types of analytic methods to evaluate economic consequences of interventions are cost– benefit analysis and cost-effective analysis. The two terms are often mislabeled and are frequently used interchangeably. The confusion in the current literature in the economic analysis of health-care delivery seems to result largely from confusion in the definition and the use of these terms. Definitions Both cost– benefit and cost-effective analyses are methods to compare the relationships between cost and clinical outcomes across different interventions. The two methods, however, differ in the expressions of effectiveness.
116 Seminars in Pain Medicine Vol. 1 No. 2 June 2003 Table 3. Index of Cost-Effectiveness for Chronic Pain: CPP versus conventional medication management versus surgical intervention Treatment CPP Conventional Surgical
Cost of treatment
Improvement
Index
$8,100 $26,000 $15,000
67% 24% 43%
0.83 0.09 0.29
Cost– benefit analysis evaluates the costs and effects of the intervention in a same, usually monetary, unit. Standardization of the unit used has an advantage because it permits comparisons across dissimilar intervention programs. On the other hand, conversion of treatment effects to a monetary unit may not always be feasible. In a cost-effective analysis, treatment outcomes are measured by criteria other than monetary terms, such as lives saved or return to work. The cost-tooutcome ratio can be estimated, and comparisons can be made between any interventions using ratios with common denominators. In a series of reports, our group31,32,40,41 demonstrated striking results of cost savings by CPPs. In a cost-effective analysis, we may ask questions about whether the treatment in question is, relative to an alternative modality42: ● ● ● ●
More effective at the same cost. At least as effective and less costly. More effective at a higher cost, but the benefit exceeds the added cost. Less effective at a lower cost, but the added benefit of alternative treatment is not worth the added cost.
One estimate,41 based on the available cost data for various health-care services, provided a figure for substantial savings in health-care expenditure of approximately $8500 per person per year, after taking the treatment cost for CPPs into consideration. The mean age of patients referred to CPPs is 45 years; the average American lives to 77 years of age.43 Thus, the average savings in a CPP can be estimated to be $272,000 per person, without accounting for increases in health-care costs over time. In an attempt to evaluate the relative cost-effectiveness of CPPs relative to standard care and surgical intervention, our group41 has also delineated an index score for cost-effectiveness, using return-to-work data as the outcome point. This index was defined as the ratio of improvement over the cost of treatment (Table 3; costs of treatment based on the data reported in the referred report). The larger the index score, the greater the level of cost-effectiveness. Based
on these figures, one may conclude that CPPs result in substantially increased cost-effectiveness in helping chronic pain patients return to work, compared with conventional medical and surgical interventions. These results are striking if one considers the patient characteristics of CPPs, discussed earlier in this study. CPPs tend to treat those patients who have not responded to conventional medical and surgical intervention.
Future Directions Heterogeneity of Chronic Pain Patients In evaluating treatment outcomes, we tend to divide patients into groups based on the primary pain diagnoses (e.g., back, headaches, fibromyalgia), considered one group sharing common features and mechanisms. This practice inevitably results in the assumption that all patients should respond similarly to a single set of CPP treatment. Given the multifactorial nature of chronic pain problems, it is reasonable to assume that patients’ clinical needs are multifaceted, with varying degrees of needs and aptitudes in each dimension. For example, research has demonstrated that chronic pain patients are quite diverse in their psychosocial characteristics.44-46 Treating such diverse needs with one set of treatment is likely to compromise the effectiveness of the treatment. Indeed, studies indicate that patients with various psychosocial characteristics respond differently to a single treatment.47-49 These results suggest that, because CPP treatment generally includes a wide range of treatment components, combinations of CPP components may be packaged differently to match patients’ clinical characteristics. Thus, future research should be asking the question of not only whether CPPs are effective, but also of what treatments should be delivered to patients in what way with what characteristics.50
Prevention Considering the adverse impact of chronic pain on patients’ lives and the society at large, preventive interventions have been of great interest in recent years. Prevention may be primary, in which attempts are made to prevent initial injury that may become chronically troublesome, or may be secondary, involving early intervention at the time of the initial injury. Recent reviews51,52 have pointed out that evaluations of single modalities, such as education, ex-
Interdisciplinary Pain Management
ercise, ergometrics, and risk factor (e.g., smoking) modifications, have yielded inconsistent results in preventing back pain. These modalities, however, may work more beneficially if administered in an integrated fashion. There is some evidence that some combinations of exercise and educational programs may help to reduce wage loss and medical costs53; however, the contributions of multidisciplinary work on prevention of chronic pain are not presently well understood. Because a history of back pain is one of the predictors of future back problems,54 secondary prevention programs could be incorporated in CPPs. Such programs would require less intensive effort when compared with rehabilitative programs treating chronic back pain, which were reviewed in this study. The preventive programs may incorporate education, body mechanics, exercise, and psychosocial interventions, particularly with regard to reduction of a pain-contingent lifestyle and modifications of risk factors with a strong focus on returning to usual activities as quickly as possible. Prospective studies are needed to evaluate the efficacy of CPPs in the secondary prevention of disability associated with chronic pain.
Conclusions Growing constraints on health-care resources has forced us to become more explicit about the accountability and evidence-based treatment outcomes in determining choice of treatment. Unfortunately, the common misperception of CPPs as being ineffective and costly seems to persist, particularly from the perspective of third-party payers. This is ironic because the literature suggests that CPP treatments are probably the most rigorously tested modality in the area of chronic pain.55 Because various biopsychosocial factors are involved in chronic pain, such as physical conditioning, operant, respondent, social learning, emotional, and cognitive factors, it is reasonable to conclude that interactions among clinicians with expertise from various disciplines would be most helpful. Reflecting this philosophical stance, outcome evaluations of CPP treatments generally provide empirical support for their effectiveness. However, CPP trials are often criticized for their methodological weaknesses. The majority of outcome studies are excluded from the Cochrane reviews for this reason. One of the problems in testing CPPs is that the conventional scientific methodology is often inapplicable in clinical trials for CPPs due to ethical concerns and the complexity of the treatment plans. Innovative thinking that goes beyond conventional RCTs is needed to improve the methodologi-
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cal integrity of CPP trials to demonstrate clinical effectiveness. From the practice point of view, although the multifactorial definition of pain56 has been widely accepted, transition of clinical practice from unimodal treatments of chronic pain to CPPs is, unfortunately, not simple. Many physicians, especially when services in the other disciplines are not easily accessible, are compelled to become a “multidisciplinary team” by themselves. It is unrealistic to ask a single physician to have a detailed understanding of psychology, PT, OT, and nursing at levels sufficient to complete comprehensive assessment and treatment of chronic pain. Nor it is not likely be a cost-effective practice. Therefore, although the consultation–liaison model of practice may have to be adopted in the absence of clinical resources, we must strive to help not only patients but also clinicians and administrators (e.g., hospital, insurance, medical school, and departments in which PTs, OTs, psychologists, and nurses are trained) understand the needs and rationale for developing CPPs. The available literature strongly suggests that CPPs offer promising treatments for chronic pain patients. Furthermore, CPPs have been shown to be more cost-effective relative to surgical and conventional medical interventions. These results are particularly impressive given that many patients have undergone other treatments without achieving satisfactory outcomes and come to CPPs as the last resort. Should those patients be referred early or undergo preventive programs, the clinical effectiveness and cost-effectiveness of CPPs would likely show improvement. It seems reasonable, therefore, to conclude that CPPs offer one of the most vital clinical options for those who suffer from chronic, disabling pain problems.
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