- Jaime Guzmán, research fellowa,
- Rosmin Esmail, Cochrane Collaboration coordinatora,
- Kaija Karjalainen, research fellowb,
- Antti Malmivaara, assistant chief physicianb,
- Emma Irvin, manager, information systemsa,
- Claire Bombardier, senior scientista
- a Institute for Work and Health, Toronto, Canada M4W 1E6
- b Finnish Institute of Occupational Health, Helsinki, Finland 00250
- Correspondence to: J Guzmán, University of Manitoba Faculty of Medicine, S112-750 Bannatyne Avenue, Winnipeg MB, Canada R3E 0W3
- Accepted 6 April 2001
Objective: To assess the effect of multidisciplinary biopsychosocial rehabilitation on clinically relevant outcomes in patients with chronic low back pain.
Design: Systematic literature review of randomised controlled trials.
Participants: A total of 1964 patients with disabling low back pain for more than three months.
Main outcome measures: Pain, function, employment, quality of life, and global assessments.
Results: Ten trials reported on a total of 12 randomised comparisons of multidisciplinary treatment and a control condition. There was strong evidence that intensive multidisciplinary biopsychosocial rehabilitation with functional restoration improves function when compared with inpatient or outpatient non-multidisciplinary treatments. There was moderate evidence that intensive multidisciplinary biopsychosocial rehabilitation with functional restoration reduces pain when compared with outpatient non-multidisciplinary rehabilitation or usual care. There was contradictory evidence regarding vocational outcomes of intensive multidisciplinary biopsychosocial intervention. Some trials reported improvements in work readiness, but others showed no significant reduction in sickness leaves. Less intensive outpatient psychophysical treatments did not improve pain, function, or vocational outcomes when compared with non-multidisciplinary outpatient therapy or usual care. Few trials reported effects on quality of life or global assessments.
Conclusions: The reviewed trials provide evidence that intensive multidisciplinary biopsychosocial rehabilitation with functional restoration reduces pain and improves function in patients with chronic low back pain. Less intensive interventions did not show improvements in clinically relevant outcomes.
What is already known on this topic
What is already known on this topic Disabling chronic pain is regarded as the result of interrelating physical, psychological, and social or occupational factors requiring multidisciplinary intervention
Two previous systematic reviews of multidisciplinary rehabilitation for chronic pain were open to bias and did not include any of the randomised controlled trials now available
What this study adds
What this study adds Intensive, daily biopsychosocial rehabilitation with a functional restoration approach improves pain and function in chronic low back pain
Less intensive interventions did not show improvements in clinically relevant outcomes
It is unclear whether the improvements are worth the cost of these intensive treatments
In many countries chronic low back pain is the most common cause of long term disability in middle age.1 Chronic low back pain is resistant to treatment, and patients are often referred for multidisciplinary treatment.2 Current multidisciplinary biopsychosocial rehabilitation regards disabling chronic pain as the result of multiple interrelating physical, psychological, and social or occupational factors.3 4
Multidisciplinary treatments for chronic pain have been evaluated in many non-randomised studies and non-systematic reviews; both are prone to bias.5 We are aware of two published systematic reviews on this topic. Flor et al reviewed 65 controlled and non-controlled studies available in 1990.6 They calculated overall effect sizes within and between groups. They concluded that multidisciplinary treatments were effective, although the methodological quality of the studies was marginal. Cutler et al combined studies of multidisciplinary treatments and of other non-surgical treatments—a total of 37 controlled and non-controlled studies.7 They concluded that non-surgical treatment of chronic pain does enable patients to return to work. Estimating treatment effects in the absence of a control group and pooling together controlled and non-controlled studies implies a high risk of bias. Furthermore, these systematic reviews included no randomised controlled trials.
We aimed to assess systematically, based on available randomised controlled trials, the effect of multidisciplinary biopsychosocial rehabilitation on clinically relevant outcomes in patients with chronic low back pain.
The study was conducted under the sponsorship of the Back Review Group of the Cochrane Collaboration. It adhered to the methodological guidelines approved by the group.8 A detailed protocol was peer reviewed and published before data were collected.9
Selection of studies for review
To be included, a study had to fulfil several criteria. Participants had to be adults with disabling low back pain for more than three months (with or without sciatica). One group of participants had to have received multidisciplinary biopsychosocial rehabilitation; a minimum of the physical dimension and one of the other dimensions (psychological or social or occupational) had to be present as defined in the protocol.9 One group of participants had to have received a control treatment that did not fulfil our criteria for multidisciplinary rehabilitation. The study had to report treatment effect in at least one of these variables: pain severity, global improvement, functional status, quality of life, and employment status. Interventions described as back schools were excluded, unless they were part of a programme that fulfilled our criteria for multidisciplinary biopsychosocial rehabilitation.
Identification and assessment of trials
We used three strategies to locate candidate randomised controlled trials: an electronic database search (using Medline, Embase, PsycLIT, CINAHL, Health Star, and the Cochrane Library from the beginning of each database to June 1998 with no language restrictions), citation tracking, and consultation with content experts.
Study selection, data extraction, and assessment of methodological quality and clinical relevance were done by two independent reviewers. Discrepancies were resolved by consensus or by a third reviewer if necessary. Our attempts to mask the names of journals and authors turned out to be impractical, as reviewers were already familiar with many of the trials.
Methodological quality was scored from 0 to 10 as recommended by the Back Review Group, even though blinding of care provider and patient might not be feasible with multidisciplinary rehabilitation.8 Clinical relevance was described by answering the following questions: are the patients described in enough detail to decide whether they are comparable to the readers' patients, is the intervention described well enough to allow readers to provide the same for their patients, and were clinically relevant outcomes measured?
We calculated treatment effect sizes between groups and 95% confidence intervals for each randomised comparison for each outcome and follow up time. We calculated relative risks for dichotomous outcomes10 and standardised mean differences for continuous outcomes. If necessary, we approximated the numbers required for calculations from graphs and statistics in the article. When the standard deviation at follow up was not available, we used the standard deviation at baseline. If none was reported, we assumed the average standard deviation reported by other studies for that outcome. All analyses were conducted using Meta-View Rev-Man software version 3.1.1 (Cochrane Collaboration, 1998).
Given the heterogeneity in study settings, interventions, and control groups, we decided not to pool effect sizes in a meta-analysis. Instead, we summarised findings by strength of evidence and nature of intervention and control treatments. 11 12 The evidence was judged to be strong when multiple high quality trials produced generally consistent findings. It was judged to be moderate when multiple low quality trials or one high quality and one or more low quality trials produced generally consistent findings. Evidence was considered to be limited when only one randomised controlled trial existed or if the findings of existing trials were inconsistent. We designated trials with methodological quality scores of 5 or more as high quality. 12 13 A trial was judged positive if it reported statistically significant benefits of multidisciplinary biopsychosocial rehabilitation compared with the control treatment, neutral if it did not report significant differences, and negative if it reported significant benefit of the control treatment compared with multidisciplinary rehabilitation.
Our search identified 32 candidate randomised controlled trials. Twenty one failed to fulfil the criteria for review. One other trial did not allow the estimation of treatment effect for any outcome.14 Thus 10 studies were included in this review. The trials were performed in Scandinavian countries,15–24 Germany, 25 26 Australia, 27 28 and Canada. 29 30 A list of excluded studies is available from the authors.
Table 1 lists the participants, interventions, and outcome measures of the trials. The trials included a total of 1964 people with low back pain. All trials excluded patients with significant radiculopathy or other indication for surgery. Most participants were workers selected from insurance listings 15 21 29 or patients referred to pain centres. 16–18 25–28 Two trials randomised patients into three groups: one control group and two treatment programmes that fulfilled our definition of multidisciplinary rehabilitation. 17 21 One trial randomised patients into six small groups in a block design.27 For this review, the four multidisciplinary rehabilitation groups are compared with the two non-multidisciplinary rehabilitation groups. Thus, the 10 trials report on 12 randomised comparisons of multidisciplinary rehabilitation and a control condition. Follow up varied from immediately after treatment, 25 26 to up to five years after treatment. 17 18
Table 2 summarises the methodological quality and clinical relevance of the trials. Most trials measured relevant outcomes and had an acceptable dropout rate and comparable timing of assessment. Four described adequate concealment of allocation. 16 27–29 None of the trials accomplished blinding of patient or care provider. Overall, the methodological quality score varied from 2 to 6 points. The Scandinavian trials were judged more clinically relevant than the others.
What kinds of multidisciplinary treatments have been tested?
Multidisciplinary biopsychosocial rehabilitation varied in setting (inpatient or outpatient) and the time and intensity of the three components (physical, psychological, and social or occupational). Programmes fell into two main categories: daily intensive programmes with more than 100 hours of therapy 15 17 18 21 26 29 and once or twice weekly programmes with less than 30 hours of therapy. 17 21 25 27 28 Five treatment programmes specifically described all three components 15–18 29; four of these were modelled on the functional restoration approach first reported by Mayer et al.31
Most programmes had standard duration and interventions (Table 1). They allowed limited individualisation in the intensity of exercise and individual psychological or social or occupational counselling. Lukinmaa et al tested highly individualised multidisciplinary rehabilitation.16 Details of the content of multidisciplinary rehabilitation programmes are given in table A on the BMJ's website. Control participants received non-multidisciplinary inpatient or outpatient rehabilitation, usual care, or no treatment (waiting list).
Are multidisciplinary treatments effective?
The figure depicts treatment effect sizes on pain, function, employment status, and sickness leaves after different lengths of follow up. According to the effect sizes and following the described criteria for strength of evidence:
There is strong evidence that intensive multidisciplinary biopsychosocial rehabilitation with functional restoration improves function when compared with inpatient or outpatient non-multidisciplinary rehabilitation.
There is moderate evidence that intensive multidisciplinary biopsychosocial rehabilitation with functional restoration reduces pain when compared with outpatient non-multidisciplinary rehabilitation or usual care.
There is contradictory evidence regarding vocational outcomes of intensive multidisciplinary biopsychosocial rehabilitation; whereas Bendix et al reported improvements in “work-readiness,”17 Alaranta et al and Mitchel et al showed no benefit on sickness leaves in two high quality trials. 15 29
Regarding less intensive multidisciplinary biopsychosocial rehabilitation, five trials could not show improvements in pain, function, or vocational outcomes when compared with non-multidisciplinary outpatient rehabilitation or usual care. 17 21 25 27 28
Two trials reported on the effect of less intensive outpatient multidisciplinary rehabilitation on quality of life, 27 28 and one reported improvement.27 Global assessments were reported in three trials.15 16 21 Table B on the BMJ's website shows details of crude outcomes.
The human and financial costs of disabling low back pain are staggering—an estimated 1.7% of the gross national product of a developed country.32 Many different rehabilitation programmes of unclear efficacy are currently in use.2 This study provides a classification of multidisciplinary biopsychosocial rehabilitation and reviews 10 randomised controlled trials of such rehabilitation for chronic low back pain, which have not been included in previous systematic reviews.6 7 We were able to locate these trials because we did not impose any language or date restrictions and because our definition of multidisciplinary rehabilitation relied on the content of the intervention rather than its name (many trials did not use the term multidisciplinary biopsychosocial rehabilitation). The studies reviewed show that intensive multidisciplinary rehabilitation with a functional restoration approach decreased pain and improved function. Less intensive programmes were not better than control non-multidisciplinary treatments.
Our findings must be interpreted in the light of the shortcomings of systematic reviews, in particular publication bias.33 Four other potential limitations need to be considered.
Firstly, this review focused on selected clinical outcomes, ignoring data on physical measurements and psychological scales. We believe that clinically relevant endpoints should be used for judging treatments for chronic low back pain. 8 34
Secondly, the cut-off point for a high quality randomised controlled trial was arbitrary. The cut-off point and the specific scale used to measure methodological quality can change the conclusions of meta-analyses.35 The scale and cut-off point used here are comparable to those of other recent systematic reviews on low back pain.12 13 If the cut off was set at 7 or more points, all the trials would be considered low quality and the strength of evidence would be moderate.
Thirdly, some assumptions were made for calculation of treatment effect sizes (see methods section). In theory, these should not bias our estimates since the same assumptions applied to intervention and control groups. Calculation of treatment effect sizes allows meaningful comparisons across trials. Crude trial outcomes are available on the BMJ's website (table).
Fourthly, the studies consisted of selected patients with severe disabling low back pain treated in well established multidisciplinary rehabilitation programmes. The results might not apply to most patients seen in primary care or to less established programmes.
Should patients with chronic low back pain be referred for multidisciplinary treatment?
Given the variability across multidisciplinary treatments, it is inappropriate to refer patients for multidisciplinary biopsychosocial rehabilitation without knowing the actual content of the programme. The reviewed trials provide evidence that intensive daily multidisciplinary rehabilitation with a functional restoration approach produces improvements in pain and function in patients with chronic disabling low back pain. Less intensive treatments did not seem to be effective.
These intensive programmes might have a large impact on healthcare resources. From the studies reviewed, it is not clear whether the benefits outweigh the costs. A crucial element in cost-benefit analyses is cost of wage replacement. Some trials reported improvement in readiness for work at follow up, but no consistent reduction in sickness leaves was reported. Also, it is not clear whether to apply human capital or friction cost analysis to estimate the cost of sickness leaves.36
The reviewed studies provide evidence that intensive (>100 hours of therapy) multidisciplinary biopsychosocial rehabilitation with functional restoration produces greater improvements in pain and function for patients with disabling chronic low back pain than less intensive multidisciplinary or non-multidisciplinary rehabilitation or usual care. Whether the improvements are worth the expense of these intensive programmes is open for discussion. The final judgment will depend on societal resources, available alternatives, and the value attached to the observed decreases in human suffering from back pain.
Contributors: JG contributed to the conception, design, and writing of the study protocol, helped to select and assess trials, conducted the data analysis, and drafted and approved the final manuscript. RE contributed to the conception, design, and writing of the study protocol, helped to select and assess trials, and revised and approved the final manuscript. KK contributed to the design and writing of the study protocol, helped to select and assess trials, and revised and approved the final manuscript. AM contributed to the design of the study protocol, helped to select and assess trials, and revised and approved the final manuscript. EI contributed to the design of search strategies and writing of the study protocol, located and obtained trial reports, and revised and approved the final manuscript. CB contributed to the conception and design of the study protocol, assembled and supervised the research team, and revised and approved the final manuscript. All the authors will act as guarantors for the paper.
Funding JG received a research fellowship from the Institute for Work and Health, an independent, not-for-profit research organisation that receives support from the Ontario Workplace Safety and Insurance Board. KK's work was supported by a fellowship from the Finnish Office for Health Care Technology Assessment. RE is currently with the Calgary Regional Health Authority, Calgary, Canada.
Competing interests None declared.
Tables detailing the content of multidisciplinary rehabilitation programmes and the crude outcomes of the trials are on the BMJ's website