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WorkSafeBC Journal Club

The Evidence Based Practice Group (EBPG) continually reviews medical literature that touches upon medical and policy issues of concern to WorkSafeBC. To assist stakeholders in understanding existing practices, selected articles that show relevance and merit are reviewed by the EBPG below. To search the page, type the Ctrl and F key at the same time.

Date posted: 2005/11/01
Topic: Homoeopathy

Citation and Review:

In July 2003, the EBPG conducted a review on the available systematic reviews on homoeopathic practices [1]. This comprehensive review provides background information on homoeopathy practice. We concluded that:

  • As of July 2003, there were > 200 clinical trials done on homoeopathy. However, most of these trials suffer from methodological errors and their results need to be interpreted with that in mind.
  • Systematic reviews on homoeopathy reveal that, with the possible exception of treating post-operative ileus and shortening the symptom duration of influenza, homoeopathy is not an effective treatment for various diseases.
  • Higher quality trials on homoeopathy show that the effect of homoeopathy is not different than the placebo effect (Level 1 evidence).

Recently, the Lancet published an updated systematic review (Level 1 evidence) entitled ‘Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy’ [2]. This is a high quality, comprehensive and transparent systematic review examining the effects of treatment, from trials of homoeopathic remedies and allopathic medicines on the same disease conditions, in a unique ‘case-control’ design of meta-analysis involving a random selection of allopathic medicine trials that served as the controls. The authors extensively evaluated the possible role of bias in these trials by employing funnel plots and meta-regression. The authors concluded that the effects seen in placebo controlled trials of homoeopathy are compatible with the placebo hypothesis. By contrast, with identical methods, the authors concluded that they found the benefits of allopathic medicine are unlikely to be explained by placebo effects.

The Editorial (‘The end of homoeopathy’ [3]) and Comment (‘Homoeopathy and “the growth of truth”’ [4]) accompanying the August 27, 2005 issue of the Lancet provide a strong opinion on the ineffectiveness of homoeopathy. An upcoming World Health Organization report on homoeopathy also drew a lot of criticism.

References

[1] Martin, Craig W. Homoeopathic practices. Review of published systematic reviews. Richmond, B.C. : WorkSafeBC, July 2003.

2] Shang A, Huwiler-Muntener K, Nartey L, Juni P, Dorig S, Sterne JA, Pewsner

D, Egger M. Are the clinical effects of homoeopathy placebo effects? Comparative study of placebo-controlled trials of homoeopathy and allopathy. Lancet. 2005 Aug 27-Sep 2 ; 366 (9487) : 726-32.

3] The end of homoeopathy. Lancet. 2005 Aug 27-Sep 2 ; 366 (9487) :690.

4] Vandenbroucke JP. Homoeopathy and "the growth of truth". Lancet. 2005 Aug 27-Sep 2 ; 366 (9487) : 691-2.

 

Date posted: 2005/10/20
Topic: A Review of occupational associations with soft tissue musculoskeletal disorders of the neck and upper limb

Citation and Review

Walker-Bone K, Cooper C. Hard work never hurt anyone: or did it? A review of occupational associations with soft tissue musculoskeletal disorders of the neck and upper limb. Ann Rheum Dis. 2005 Oct ; 64(10): 1391-6.

This is an interesting review on the possible association between work and soft tissue disorders of the neck and upper limb. In this review the authors provide important precautions for the methodological limitations among epidemiological studies in this area. The precautions include:

  • Until recently, epidemiological studies did not employ a common classification system for these conditions.
  • The majority of the studies were cross-sectional in nature and, as such, issues on causation cannot be appropriately established.
  • Variation in the exposure assessment methods may result in misclassification.

Regarding the association between work and neck and upper limb soft tissue disorders the authors concluded that:

  • The evidence suggests that neck pain and neck disorders are associated with mechanical and psychosocial workplace factors ( association does not mean causation). To date, the preventive effectiveness of neck schools, which is based predominantly on ergonomic principles, is not convincing.
  • With regard to shoulder disorders: Overhead work is an established risk factor and repetitive work is probably a risk factor (based on 2 systematic reviews). The evidence also suggests that psychological and occupational psychosocial variables have an important role.
  • Jobs that involve exposures to combinations of force, repetition and/or vibration may be associated with lateral epicondylitis. It may also be associated with low levels of psychological well being.
  • Non-specific forearm pain (also known as repetitive strain injury or RSI) is associated with psychological distress, aspects of illness behaviour (largest size of association), other somatic symptoms, other psychosocial factors including supports from supervisor/colleague and mechanical factors such as repetitive tasks.
  • Systematic reviews concluded that workplace factors, including exposure to force and/or repetitive motion, exposure to hand/wrist vibration and awkward arm, wrist and finger postures, probably contribute to carpal tunnel syndrome ( it should be noted that primary studies in carpal tunnel syndrome had some controversies, especially with regard to the case definition).

Overall, the authors concluded that due to methodological problems in the primary research in this area, it is impossible to draw a conclusion regarding the relative importance of mechanical and psychosocial risk factors in the etiology of upper limb disorders.

The EBPG would like to remind the reader that that the paper by Walker-Bone and Cooper is not a systematic review (expert review - level 5 evidence), the selection process of the primary papers/research is not completely transparent and the authors did not provide any framework on how causation was established.

Date posted: 2005/10/11
Topic: Environmental and Occupational Causes of Cancer

Citation and Review:

Clapp RW, Howe G and Lefevre MJ. Environmental and occupational causes of cancer: a review of recent scientific literature. University of Massachusetts Lowell. Boston University School of Public Health and the Environmental Health Initiative. September 2005. Available at: http://www.healthandenvironment.org/working_groups/cancer#1
Accessed October 10, 2005

This paper provides extensive and up-to-date epidemiological evidence regarding the potential contribution of various environmental and occupational exposures to cancer. The most notable conclusions from this paper are:

  • Cancer evolves from a complicated combination of multiple exposures.
  • Attempting to assign certain exposures with an etiological fraction that adds up to 100% is inappropriate given that no one exposure single handedly produces cancer and many causes of cancer are still unknown.
  • The authors suggested that strong causal links between environmental-occupational exposures and cancer occur in:
    • Metals, e.g. arsenic, with bladder, lung and skin cancers
    • Chlorination byproducts, e.g. trihalomethanes, with bladder cancer
    • Natural fibers, e.g. asbestos, with larynx, lung, mesothelioma and stomach cancers
    • Petrochemicals and combustion products, including motor vehicle exhaust and polycyclic hydrocarbons, with bladder, lung and skin cancers
    • Pesticide exposures with brain cancer, Wilms tumor, leukemia and non-Hodgkin's lymphoma
    • Reactive chemicals, such as vinyl chloride, with liver cancer and soft tissue sarcoma
    • Metalworking fluids and mineral oils with bladder, larynx, nasal passages, rectum, skin and stomach cancers
    • Ionizing radiation with leukemia, multiple myeloma, sarcomas, bladder, bone, brain, breast, liver, lung, ovary, skin and thyroid cancers
    • Solvents, e.g. benzene and with leukemia and non Hodgkin's lymphoma; tetrachloroethylene and bladder cancer; trichloroethylene and Hodgkin's disease, leukemia, kidney and liver cancers
    • Environmental tobacco smoke and cancers of the breast and lung

The EBPG has some reservations regarding this report. This is due to the fact that there was no information provided by the authors on the critical appraisal and the level of evidence of the primary or secondary studies used in this report. Further, the authors did not provide clear information on the way causation was established.

Date posted: 2005/10/11
Topic: Cold shock and swimming failure

Citation and Review:

Brooks CJ, Howard KA and Neifer SK. How much did cold shock and swimming failure contribute to drowning deaths in the fishing industry in British Columbia 1976-2002? Occup Med (Lond). 2005 Sep;55(6):459-62.

Under commission from WorkSafeBC, Brooks et al investigated the underlying causes of the drownings that occurred in the British Columbia (BC) fishing industry during the period of 1976-1992. In this case series (level 4 evidence), the authors found that there were 89 immersion accidents in the BC fishing industry causing 122 male and 8 female death. While the swimming capability of the majority (86.1%) of the victims was unknown, 8 (6.2%) of these victims could not swim. Flotation devices were not carried in 5 (5.6%) accidents and their existence was unknown in 56 (62.9%) accidents. No flotation devices were worn by 70 (53.8%) victims and their existence was unknown for 40 (30.8%) victims.
In the majority (72.2%) of cases, the authors could not conclude the underlying cause of drowning. Seven (5.4%) were classified as due to cold shock, 7 (5.4%) were due to swimming failure, 7 (5.4%) were due to hypothermia, 1 (0.8%) was due to post-rescue collapse, 1 (0.8%) was due to cardiac event after immersion and 13 (10.0%) were due to drowning.

Date posted: 2005/09/28
Topic: Role of Bone Growth Stimulating Devices and Orthobiologics in Healing Nonunion Fractures

Citation and Review:

Schoelles, K et al. The Role of Bone Growth Stimulating Devices and Orthobiologics in Healing Nonunion Fractures. US Emergency Care Research Institute. Evidence Based Practice Center. September 21, 2005. Available at: https://www.cms.hhs.gov/coverage/download/id30M.pdf Accessed: September 9, 2005

This is a comprehensive, up-to-date (up to August 2005), and high-quality systematic review conducted by the US Emergency Care Research Institute's Evidence Based Practice Center under contract to the US Agency for Healthcare Research and Quality (AHRQ). The Center for Medicare and Medicaid Services requested this review.
The objectives of this systematic review include: diagnosis of nonunion, risk factors for developing nonunion, current standards of care for nonunion fractures, intermediate and patient reported outcomes of treatments for nonunion, variation in treatment outcomes due to various factors and the effectiveness of bone growth stimulators and orthobiologics for treatment of nonunion fractures. The effectiveness of orthobiologics and bone growth stimulating devices is summarized here:

  • Various factors affect the bone healing process. Two of these factors are the availability of bone growth factors to stimulate the production of cells needed in the healing process and the type of stress applied to the bone during healing.
  • Biophysical stimulation has been proposed as a key element in repairing, maintaining and remodeling bone to meet its' functional demands. However, the direct link between biophysical stimulation and the cellular responses controlled by various growth factors has not been fully understood.
  • External energy sources, such as those delivered by ultrasound, pulsed electromagnetic field stimulation (PEMF), low power direct current and extracorporeal shock wave stimulation (ESWT), are thought to enhance fracture healing, even though their physiological mechanism is still controversial.
  • In this systematic review, 24 studies of bone growth stimulating devices and orthobiologics that met the inclusion and exclusion criteria were identified. These studies include 3 of ultrasound, 7 of PEMF, 4 of direct current and capacitive coupling, 6 of ESWT and 4 of orthobiologics. Only 4 RCTs (2 for PEMF, 1 for capacitive coupling and 1 for orthobiologics c.q. Stryker Biotech OP-1®) were identified in this systematic search, hence the majority of evidence available was of lower quality.
  • The authors concluded that while there is some suggestive evidence of the effectiveness of ultrasound (Exogen®), PEMF, ESWT, AlloMatrix Injectable Putty®, demineralized bone matrix, direct current and capacitive coupling to promote healing of nonunion fractures, the effect of these therapies cannot be separated from the effect of immobilization in these majority, uncontrolled studies.
  • One RCT comparing Stryker Biotech OP-1® (BMP-7) implants vs. fresh bone autografts among patients with tibial nonunion fracture (both with additional intramedullary rod fixation) showed similar healing rates. However, the authors rated the study of fair quality due to the problem in blinding the patients in the fresh bone autograft group. Further, the authors cautioned that the study needed to be replicated before OP-1® can be considered as an effective substitute for autogenous bone grafting.
Date posted: 2005/09/28
Topic: Low-intensity ultrasound (Exogen®) for the treatment of fractures

Citation and Review:

Banker, Reiner. Low-intensity ultrasound (Exogen®) for the treatment of fractures: a summary. Québec Health Technology Assessment Agency. 2004. Available at: http://www.aetmis.gouv.qc.ca/site/download.php?f=c8937c8d9a19e9d3bf631ffdbd40aa48 Accessed September 21, 2005.

This is a systematic review which was originally published (French version) in late 2003 by the Agence D'Evaluation des Technologies et des Modes D'Intervention en Sante (Québec Health Technology Assessment Agency). The objective of this systematic review was to investigate the effectiveness of low intensity ultrasound in preventing nonunion, in accelerating bone healing and in treating nonunion.
It is unfortunate that the English summary does not describe the methodology employed in this systematic review. As such, the EBPG cannot evaluate the quality of this systematic review. However, based on its membership in the the International Network of Agencies for Health Technology Assessment and from past published systematic reviews, the Québec AETMIS upholds a high quality of standard.
Results:

  • There is no evidence that low intensity ultrasound (Exogen®) can prevent nonunion in high risk patient populations.
  • There was weak evidence in the efficacy of low intensity ultrasound (Exogen®) in accelerating bone healing.
  • There is no evidence on the efficacy of Exogen® in treating fracture nonunion.
Date posted: 2005/09/01
Topic: Electrotherapy for neck disorders.

Citation and Review:

Recently, the Cochrane Library updated and published three topics that may be of interest to us. The EBPG summarizes these high quality systematic reviews below.

Kroeling P, Gross A, Goldsmith CH, Cervical Overview Group. Electrotherapy for neck disorders. The Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD004251.pub3. DOI:10.1002/14651858.CD004251.pub3.

Electrotherapy is commonly used to treat mechanical neck disorders. The types of electric currents and their putative therapeutic effects include:

  • Galvanic current. This treatment modality through the application of DC (direct current) supposedly reduces pain by inhibiting nociceptor activity. The main indication for Galvanic current is the treatment of acute radicular pain and inflammation of periarticular structures such as tendons and ligaments.
  • Electrical nerve stimulations (ENS or TENS). The AC or modulated DC in this device may be effective in inhibiting pain related potentials on the spinal or supra spinal level, known as gate control.
  • Electrical Muscle Stimulation ( EMS). EMS is similar to TENS. The difference is in the intensity which leads to additional muscle contractions.
  • Pulsed ElectroMagnetic Fields (PEMF) and permanent magnet.  In this device, electricity is always connected with both electrical and magnetic forces.
    In their attempt to assess the effect of the above mentioned electrotherapy methods on pain, function/disability, patient satisfaction and global perceived effects in adults with mechanical neck disorders, the authors found that:
  • The contribution of Galvanic current in treating acute, subacute or chronic occipital headache cannot be determined.
  • There is no evidence on the effectiveness of Diadynamic current (ENS) in treating mechanical neck disorder.
  • The contribution of iontophoresis in treating whiplash associated disorders cannot be determined.
  • The evidence for TENS in treating patients with whiplash associated disorders, acute mechanical neck disorder or chronic neck disorder with radicular findings is conflicting, at best.
  •  There is limited evidence that permanent magnets are not effective in treating chronic neck and shoulder pain.
  •  There is limited evidence that extremely low frequency PEMF slightly reduces pain in people with chronic cervical spine osteoarthritis. However, compared to placebo, patient’s global assessment and activities of daily living were not improved.

Overall, it can be concluded that, at present, there is no evidence on the effectiveness of electrotherapy in treating mechanical neck disorders.

 

Date posted: 2005/09/01
Topic: Antidepressants for neuropathic pain.

Citation and Review:

Saarto T, Wiffen PJ. Antidepressants for neuropathic pain. The Cochrane Database of Systematic Reviews 2005, Issue 3. Art. No.: CD005454. DOI: 10.1002/14651858.CD005454.
 
For many years antidepressants (and anticonvulsants) have been used in treating neuropathic pains. However, the mechanism of action of the antidepressants in treating neuropathic pain remains uncertain. Two main groups of antidepressants are in common use, including the older TCAs (e.g. amitriptyline, imipramine) and the newer group of SSRIs, SNRIs and RIMAs.
In this high quality systematic review, the authors investigated the analgesic effectiveness and adverse effects of antidepressants, including TCAs, MAOIs, SSRIs, SNRIs, RIMAs, St. John's Wort and others (e.g. bupropion, etoperidone, nefazodone etc) in treating neuropathic pain.
The authors found that:

  • TCAs are effective in treating diabetic neuropathy, postherpetic neuralgia, atypical facial pain, neuropathy of traumatic, surgical or infectious origin, central pain and polyneuropathy. For at least moderate pain relief, the Number Needed To Treat (NNT) calculated for amitriptyline is 2 for doses up to 150 mg daily, and for desipramine it is 2.1.
  • There is lack of evidence in the effectiveness of TCAs in treating burning mouth syndrome and HIV related neuropathies.
  • Studies comparing TCAs against other TCAs could not identify which TCA was better.
  • St. John’s Wort was slightly better than placebo in treating polyneuropathy
  • Sleep was improved with amitriptyline, imipramine or bupropion compared to placebo.
  • Minor side effects (harm) observed included drowsiness, dizziness, dry mouth, constipation, nausea, urinary retention, sweating, headache, blurred visions, palpitations, irritability and ataxia. The Number Needed to Harm for minor side effects for TCAs is calculated at 4.6.
  • The Number Needed to Harm for major side effects (i.e. for patients to withdraw from the trials) for TCA is calculated at 16.
  • There is limited evidence that newer SSRIs may be effective.

 Overall, it can be concluded that antidepressants are effective in treating neuropathic pains. The best evidence available is for amitriptyline. The effect of antidepressants is independent of any effect on depression.

 

Date posted: 2005/09/01
Topic: Surgery for degenerative lumbar spondylosis.

Citation and Review:

Gibson JNA, Waddell G. Surgery for degenerative lumbar spondylosis. The Cochrane Database of Systematic Reviews 2005, Issue 2. Art. No.: CD001352.pub2. DOI: 10.1002/14651858.CD001352.pub2.
 
Degeneration of lumbar spine (lumbar spondylosis) may lead to spinal stenosis, vertebral instability and/or vertebral malalignment which may be associated with back pain and/or leg symptoms. Symptoms associated with lumbar spondylosis vary in severity and have a relatively low correlation with the severity of anatomical or radiographic changes. Small proportions of these patients come to surgery. Surgical treatment may take the form of fusion and/or decompression; and lately intradiscal electrotherapy (IDET) and artificial discs. However, currently there is a lack of evidence in the role of instability and the clinical indications for surgery are not well defined. There is also wide variation in the surgical rate and techniques being used. The objective of this high quality systematic review is to investigate the effectiveness of these surgical interventions in treating lumbar spondylosis.

The authors found that:

  • Older trials on surgical fusion were of lower quality compared to more recent trials
  • With regard to spinal stenosis and decompressions:
    • There is no clear evidence of which techniques or the extent of the decompression is the most effective.
    • There is limited evidence that adjunct fusion to supplement decompression for degenerative spondylolisthesis produces less progressive slip and better clinical outcomes than decompression alone.
    • There is limited evidence that fusion alone may be as effective as fusion + decompression for grade I or II isthmic spondylolisthesis.

  • Trials on instrumented fusion varied widely clinically and statistically, hence firm conclusion cannot be obtained. Given these limitations:

    • Instrumentation of a posterolateral fusion seems to lead a higher fusion rate.
    • Despite enhancing fusion, there is strong evidence that instrumentation does not improve clinical outcomes.
    • Trials on the effectiveness of fusion compared to conservative treatments showed that fusion is no more effective than modern rehabilitation programme in treating chronic low back pain patients.
  • At the time of this review, it is not possible to draw any conclusion on the effectiveness of IDET and lumbar arthroplasty. It should be noted that the EBPG has published a systematic review on the effectiveness of artificial disc.


Overall, it can be concluded that there is still insufficient evidence on the effectiveness of surgery on clinical outcomes among patients with lumbar spondylosis.

 

Date posted: 2005/08/15
Topic: Patellar resurfacing in total knee arthroplasty. A meta analysis.

Citation and Review:

Pakos EE, Ntzani EE, Trikalonos TA. Patellar resurfacing in total knee arthroplasty. A meta analysis . Journal of Bone and Joint Surgery. American edition. July 2005;87A(7):1438-1445.
 
The treatment of the patella at the time of total knee arthroplasty remains controversial. The persistent or recurrent anterior knee pain that occurred at high rates following treatment with early implants, as well as other complications such as dislocation, maltracking and subluxation, typically were attributed to the patellofemoral joint. In this good (one step below the highest rank) quality systematic review, the authors attempted to answer several questions, including whether re-operation was less needed when the patella was resurfaced, the association, if any, between post-operative anterior knee pain with method of treatment (i.e. total knee arthroplasty with or without patellar resurfacing) and the mean improvement in the total knee score associated with each type of treatment.

The authors found that:

  • Overall, the frequency of re-operations in the patellar resurfacing group was 0.5 times lower than in the non resurfacing group. The effect was greater (0.2 times) and was statistically significant among studies that have 5 years follow-up.
  • Overall, the absolute risk of re-operation was reduced by 4.6% in the patellar re-surfacing group (need to re-surface 22 patellae to prevent one re-operation). Again, the absolute risk of re-operation was lower (6.7%) and statistically significant among studies that have 5 years follow-up (need to re-surface 15 patellae to prevent one re-operation).
  • Overall, the presence of post-operative anterior knee pain of any grade was 0.4 times lower in the resurfacing group. Overall, patellar resurfacing reduced the absolute risk of post-operative anterior knee pain by 14% (need 7 patellae to prevent one case of post operative anterior knee pain).
  • Meta-analysis on the various knee function scoring systems (including Knee Society Score, Bristol Knee Score and Hospital for Special Surgery Knee Score) did not show any difference between resurfacing and non-resurfacing group. However, the authors cautioned the heterogeneity, incompleteness and lack of data reported in general with regard to knee function scores in these RCTs.


Based on this meta analysis, it can be concluded that, with regard to the frequency of re-operation and post operative anterior knee pain, patellar resurfacing is marginally superior than non resurfacing.

 

Date posted: 2005/08/15
Topic: The power of the placebo.

Citation and Review:

(1) Moseley JB, O'Malley K, Petersen NJ, Menke TJ, Brody BA, Kuykendall DH, Hollingsworth JC, Ashton CM, Wray NP. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med. 2002 Jul 11;347(2):81-8.

(2) Rana JS, Mannam A, Donnell-Fink L, Gervino EV, Sellke FW, Laham RJ. Longevity of the placebo effect in the therapeutic angiogenesis and laser myocardial revascularization trials in patients with coronary heart disease. Am J Cardiol. 2005 Jun 15;95(12):1456-9.

This landmark trial by Moseley et al (1) showed that at no point during the 24 month follow-up was there a significant difference in pain or self-reported physical function among the patients randomly assigned to receive arthroscopic debridement, arthroscopic lavage or placebo arthroscopic debridement.
One might argue that these were subjective end point measurements. However, a recent article by Rana et al (2) that was published in the June 15, 2005 issue of the American Journal of Cardiology shows that similar placebo effect was also observed among end stage coronary heart disease patients. More importantly, the effect was maintained for at least 24 months including in the measurements of exercise treadmill time, mean Canadian Cardiovascular Society angina class and the SF-36 quality of life. This observation was done among placebo group of an angiogenesis and laser myocardial revascularization trial participants. Based on the observation that placebo effect was maintained for at least 24 months the authors strongly suggested that persistence of therapeutic effect in open label trials could not be used as evidence of efficacy because the placebo effect might last as long. As such, double blinding is essential and blinding should be maintained long term if possible.

 

Date posted: 2005/08/04
Topic: Costs and outcomes of chiropractic treatment for low back pain.

Citation and Review:

Brown A, Angus D, Chen S, Tang Z, Milne S, Pfaff J, Li H, Mensinkai S. Costs and outcomes of chiropractic treatment for low back pain [Technology report no 56]. Ottawa: Canadian Coordinating Office for Health Technology Assessment; July, 2005.

Recently, the Canadian Coordinating Office for Health Technology Assessment (CCOHTA) published a high quality systematic, clinical and economic review of chiropractic care for low back pain (LBP). The review was conducted to shed light on the uncertainty of the clinical and cost effectiveness of chiropractic care compared with standard medical treatment or physical therapy in treating LBP (acute, subacute and chronic). This is a comprehensive review, including the reimbursement practices of chiropractic care across Canada, that attempts to provide answers to decision makers involved in the provision of chiropractic services across Canada.

Major findings of this study include:

  • There is no clear clinical advantage to chiropractic treatment for LBP versus standard medical care or physical therapy. Studies show that the three treatment methods have similar effects on pain relief and functional improvement. The higher quality reviews did not find significant differences in effectiveness.
  • There is no clear cost advantage for any of the three methods studied. One of the included economic studies compared chiropractic care with physical therapy; and found costs to be similar. Cost results varied among the studies comparing chiropractic care with standard medical care. In terms of improving lost time from work, chiropractic care was similar to physical therapy and was effective as or better than standard medical care.

In summary, chiropractic care for LBP is similar in effectiveness to that of standard medical care and physical therapy. The evidence from other countries is inconclusive about the costs for chiropractic treatment of LBP, relative to physical therapy or medical care. The authors suggest that a well-designed Canadian study that compares the cost-effectiveness of LBP care provided by chiropractors, physical therapists and primary care physicians, would be beneficial.

 

Date posted: 2005/08/04
Topic: Meta-analysis: acupuncture for low back pain.

Citation and Review:

Manheimer E, White A, Berman B, Forys K and Ernst E. Meta-analysis: acupuncture for low back pain. Annals of Internal Medicine. April 2005;142:651-663.

This is a high quality systematic review and meta analysis investigating the relative effectiveness of acupuncture against sham (penetrating or non penetrating) acupuncture, other sham (c.q. sham TENS), no treatment and active treatments (c.q. massage, medication, spinal manipulation and TENS). It should be noted that the authors considered a minimum of 10 mm difference in the VAS for pain (out of 100) and a 2 point difference in Roland Disability score (in function) as clinically important difference.

Major findings from this study include:

  • There was not enough data to draw any conclusion for ACUTE LOW BACK PAIN patients.
  • For CHRONIC LOW BACK PAIN patients:
    • short term outcome (< 6 weeks) on PAIN, acupuncture is:
      • clinically significantly better than sham acupuncture, sham TENS, no additional treatment
      • marginally (not clinically but statistically only) significantly better than medication or TENS
      • massage is marginally (not significant) better
      • spinal manipulation is clinically significantly better
    • long term outcome (> 6 weeks) on PAIN, acupuncture is:
      • clinically significantly better than sham acupuncture, sham TENS, no additionaltreatment
      • marginally significantly better than TENS
      • massage is clinically significantly better than acupuncture
    • short term FUNCTIONAL STATUS, acupuncture is:

      • clinically significantly better than no additional treatment; not statistically significantly better than sham acupuncture
      • marginally (not statistically) better than TENS
      • massage, medication and spinal  manipulation are clinically significantly better than acupuncture
    • long term FUNCTIONAL STATUS:
      • marginally but not statistically significantly better than sham acupuncture or no additional treatment
      • massage is marginally but not statistically significantly better than acupuncture

Perhaps, it can be concluded that acupuncture affects the pain but not the functional status of the chronic low back pain patients.

 

Date posted: 2005/07/13
Topic: Metal on Metal Hip Resurfacing
Citation and Review:

Recently, the EBPG received several questions regarding Metal on Metal (MoM) hip resurfacing (HR). MoM is a fairly new technology and, fortunately, we were able to identify several systematic reviews on this topic that had already been conducted by some of the world leaders in health technology assessment (HTA) [See references at the end of this review].

Several good systematic reviews on MoM have been published by various organizations including the NHS Health Technology Assessment Programme [1]  (this article was re-published in BMC Health Services Research [2]), the NHS National Horizon Scanning Centre [3] in the UK (these two systematic reviews became the framework for the UK National Institute for Clinical Excellence (NICE) guidance on MoM HR issued in 2002 [4]), the Centre for Clinical Effectiveness [5], the Australian Safety and Efficacy Register of New Interventional Procedures - Surgical [6], the Canadian Coordinating Office for Health Technology Assessment [7] [8] and the Alberta Heritage Foundation HTA [9].  Almost all of these systematic reviews used the 2002 NHS Health Technology Assessment Review [1] as their baseline and expanded from there.

The NICE issued a guidance document on the application of MoM in the UK NHS system in June 2002 [4] and this was updated in February 2005 [10]. The February 2005 [10] update on the MoM guidelines stated that due to the paucity of new evidence NICE still adheres to the conclusions and guidance on the application of MoM HR outlined in the original June 2002 [4] document.

Summary of the available systematic reviews and guidelines on the MoM:

  • There was no evidence regarding medium to long term safety and reliability of these devices or the likely outcome of revision surgery when compared with conventional total hip arthroplasty
  • The systematic reviews noted that there were no randomized controlled trials (RCTs) or head to head trials comparing MoM with total hip arthroplasty (THA). Evidence used came from 8 observational studies (of which only 4 have been published) including 3 studies from the product manufacturers
  • Scant data is available on the dislocation rates of MoM. Birmingham Hip (the only data available at the time) showed 0.05% dislocation rates in the year following surgery
  • Device revision surgery ranged from 0% - 14.3%
  • No data was available on device survival rates, while the survival rates for THA ranged from 92%-94% at 7 years among those patients aged <= 55 years
  • MoM is recommended as an option for people with advanced hip disease (majority of primary research came from patients with osteoarthritis (OA)) who would otherwise receive a conventional primary total hip replacement (THR) and are likely to live longer than the device is likely to last (the majority of THRs last for at least 10-15 years amongst people with various degree of activity levels)
  • Patient level of activity is more important than age of patients when deciding on which procedure to undertake (majority of primary research was done among those younger than 65 years old)
  • Surgeons should inform patients that there is no long term (> 10 years) follow up data available at present
  • It is a requirement that prospective patients have good bone stock for MoM. As such, it is suggested that patients with diseases that reduce the viability of the femoral head are contraindications for this procedure.
  • Cautious assessment should be done among patients with existing osteonecrosis and rheumatoid arthritis prior to MoM HR. Osteoporosis is also considered as one contraindication for MoM HR.
  • CCOHTA cautioned that gaining proficiency in the operating procedure is challenging, especially with the new minimally invasive procedures. At the time of their report (March 2005), the number of Canadian surgeons with the appropriate skills was still limited. The Canadian joint replacement registry is currently collecting data (since 2003) on MoM outcomes so hopefully we'll see some higher quality patient selection criteria as well as outcomes in the near future
  • Currently, Health Canada licenses four products (Birmingham Hip, Conserve Plus, ReCap Femoral and Durom) under normal licensing and two (Cormet and DePuy) under special needs licensing MoM in Canada
  • WITH REGARD TO PATIENTS WITH AVN, partial/hemi hip resurfacing in which a femoral shell is implanted over the femoral head is considered an established procedure for patients with good acetabular cartilage and without secondary OA.
    Recently Grigoris et al [11] and Clarke et al [12] wrote interesting historical articles on the development of MoM published in the Orthopedic Clinics of North America.


References:

[1]   Vale L, Wyness L, McCormack K, McKenzie L, Brazzelli M, Stearns SC.
 A systematic review of the effectiveness and cost-effectiveness of metal-on-metal hip resurfacing arthroplasty for treatment of hip disease. Health Technol Assess. 2002 ; 6(15): 1-109.

[2]  Wyness L, Vale L, McCormack K, Grant A, Brazzelli M.  The effectiveness of metal on metal hip resurfacing: a systematic review of the available evidence published before 2002. BMC Health Serv Res. 2004 Dec 27 ; 4(1): 39.

[3]  National Horizon Scanning Centre. Metal on metal resurfacing hip arthroplasty (hip resurfacing).  December 2000.  Available at: http://pcpoh.bham.ac.uk/publichealth/horizon/PDF_files/2000reports/HipResurfacing.pdf Accessed July 13, 2005

[4]  National Institute for Clinical Excellence. Press release: NICE recommends the selective use of metal on metal hip resurfacing.  NICE 2002/34, issued: 19 June 2002. Available at: http://www.nice.org.uk/page.aspx?o=33569 Accessed July 13, 2005

[5]  Bernath, Vivienne.  Hip resurfacing in patients with osteoarthritis.  Centre for Clinical Effectiveness, November 2002. Available at: http://www.med.monash.edu.au/healthservices/cce/evidence/pdf/b/910%20Report.pdf Accessed July 13, 2005

[6] Australian Safety and Efficacy Register of New Interventional Procedures – Surgical. Metal hip resurfacing.  Royal Australasian College of Surgeons. 2001. Available at: http://www.surgeons.org/asernip-s/net-s/procedures/Metal_Hip_Resurfacing_Prosthesis.pdf Accessed July 13, 2005

[7]  Canadian Coordinating Office for Health Technology Assessment (CCOHTA).  Pre-assessment : metal-on-metal hip resurfacing.  CCOHTA n.19, March 2003. 

[8]  Allison C. Minimally invasive hip resurfacing [Issues in emerging health technologies ; issue 65]. Ottawa: Canadian Coordinating Office for Health Technology Assessment; 2005.

[9]  Health Technology Assessment Unit. Alberta Heritage Foundation for Medical Research. Metal-on-metal hip resurfacing for young, active adults with degenerative hip disease.  Technote, TN 33, March 2003.

[10]  National Institute for Health and Clinical Excellence. Review proposal. Available at: http://www.nice.org.uk/page.aspx?o=259479 Accessed July 13, 2005

[11]  Grigoris P, Roberts P, Panousis K, Bosch H. The evolution of hip resurfacing arthroplasty. Orthop Clin North Am. 2005 Apr;36(2):125-34, vii.

[12]  Clarke IC, Donaldson T, Bowsher JG, Nasser S, Takahashi T. Current concepts of metal-on-metal hip resurfacing. Orthop Clin North Am. 2005 Apr;36(2):143-62, viii.

 

Date posted: 2005/06/29
Topic: Efficacy and safety of opioid agonists in the treatment of neuropathic pain of nonmalignant origin
Citation and Review:

Eisenberg E, McNicol ED, Carr DB. Efficacy and safety of opioid agonists in the treatment of neuropathic pain of nonmalignant origin: systematic review and meta-analysis of randomized controlled trials. JAMA. 2005 Jun 22;293(24):3043-52.

  • The objectives of this high quality systematic review and meta-analysis (level 1 evidence) were to investigate the effectiveness and the side effects of opioid agonists in patients with neuropathic pain. The authors separated the effect of opioids into two randomized controlled trials, those originated from short term (< 24 hours) and those from intermediate term (between 8 – 56 days, median 28 days). The results of the intermediate term are summarized here.
  • The data were derived from 8 (403 patients) high quality, primary research studies on oral opioids, including long acting oxycodone, morphine, methadone and levorphanol.
  • The pain etiology included post herpetic neuralgia, phantom limb (12 patients), diabetic neuropathy and mixed neuropathy.
  • All trials reported that opioids were efficacious in reducing spontaneous neuropathic pain or in a dose dependent analgesic response (levorphanol) compared to placebos.
  • Data on pain intensity from 6 (out of 8) studies were pooled in a meta-analysis and showed that the overall mean pain intensity among opioid-treated patients was -14 points (i.e. lower) (95% CI -18 to -10) than those treated with placebos (out of 100 point scale).
  • The commons side effects included:
    - Nausea, with number needed to harm (NNH)  3.6 (95% CI 2.9 – 4.8).
    - Constipation, with NNH 4.6 (95% CI 3.4 – 7.1)
    - Drowsiness, with NNH 5.3 (95% CI 3.7 – 8.3)
    - Vomiting, with NNH 6.2 (95% CI 4.6 – 11.1)
    - Dizziness, with NNH 6.7 (95% CI 4.8 – 10.0)
  • Overall, 13.5% of patients in the opioid studies withdrew because of side effects compared to 7.6% of patients in the placebo studies.
  • It should be noted that there was no data on the efficacy or side effects for longer term treatment.

It should be noted that none of the primary studies addressed the issues on addiction and abuse.

 

Date posted: 2005/06/29
Topic: Overutilization of shoulder magnetic resonance imaging as a diagnostic screening tool in patients with chronic shoulder pain.

Citation and Review:

Bradley MP, Tung G, Green A. Overutilization of shoulder magnetic resonance imaging as a diagnostic screening tool in patients with chronic shoulder pain. J Shoulder Elbow Surg. 2005 May-Jun;14(3):233-7.

In this large, good quality case series (Level 4 evidence) of 101 consecutive new patients with non-traumatic onset of shoulder pain Bradley et al investigated the utility of screening MRI for patient treatment and outcome. Patients were recruited prospectively; hence data on Simple Shoulder Test scores, visual analog scale (VAS) scores on pain, function and quality of life (QoL), were also collected prospectively. However, data collections on various other aspects were collected retrospectively in order not to influence the practice of the independent care givers.

Patients were divided into those who came with MRI already done (Group 1) and those who did not have prior MRI (Group 2). The patients were then followed for between 8-11 months (mean 9.1 months) after the initial assessments. The authors did not provide enough detail on the characteristics of the patients.

The authors found that there was no difference between those who came with MRI and those who did not have prior MRI with regards to diagnosis, initial and final outcome scores in SST and VAS pain, function and QoL, physical therapy or shoulder surgery. The incidence of surgery among those diagnosed with full thickness rotator cuff tears was similar among Group 1 and Group 2 (whom subsequently got MRI). By employing certain, probably debatable, formula, the authors estimated that the overutilization of MRI in Group 1 to be 90%.

The authors concluded that routine pre-evaluation with MRI did not appear to have significant impact on the treatment or outcome of patients with non-traumatic shoulder pain. The authors suggested that MRI should not be used as a screening tool for non-traumatic shoulder pain before a comprehensive clinical evaluation of the shoulder.

 

Date posted: 2005/06/16
Topic: Arthroscopic Versus Open Repair for Traumatic Anterior Shoulder Instability: A Meta-analysis.
Citation and Review:

Mohtadi NG, Bitar IJ, Sasyniuk TM, Hollinshead RM, Harper WP. Arthroscopic versus open repair for traumatic anterior shoulder instability: a meta-analysis. Arthroscopy. 2005 Jun;21(6):652-8.

n this (not so strong methodologically) meta-analysis the authors conducted a thorough search (the major strength of this study) in the Medline database (1966-Oct 2003) as well as manual searches on anterior shoulder instability. Of the 981 abstracts reviewed, 11 studies were appraised and the results were combined into a meta-analysis. The combined results showed that the odds of having recurrent instability was 2.0 (95% CI 1.3 – 3.3) for those having arthroscopic repairs compared to open repair. When the lower level studies were excluded (case controls and retrospective cohorts) the result remained similar. Further, the odds of returning to activity was 2.9 (95% CI 1.4 – 5.8) favoring open repair. The plotting of the odds ratio of the primary studies suggested that open repair was more favorable than arthroscopic repair with regard to recurrent instability or return to activity. The results of this meta-analysis need to be interpreted cautiously.

 

Date posted: 2005/05/27
Topic:

Exercise therapy for low back pain

Citation and Review:

(1) Hayden JA, van Tulder MW, Malmivaara AV, Koes BW. Meta-analysis: exercise therapy for nonspecific low back pain.  Ann Intern Med. 2005 May 3;142(9):765-75.
(2) Hayden JA, van Tulder MW, Tomlinson G. Systematic review: strategies for using exercise therapy to improve outcomes in chronic low back pain. Ann Intern Med. 2005 May 3;142(9):776-85.
 
A meta-analysis (level 1 evidence) and a high quality systematic review on the effectiveness of exercise in treating nonspecific low back pain (LBP) were published by the same authors in the May 3, 2005 edition of the Annals of Internal Medicine. These studies were also featured in the May 3, 2005 edition of the Globe and Mail, in an article entitled "Exercise: Don't take back pain lying down" (page A15).
 
The first paper (1) evaluated the effectiveness of exercise therapy, compared to no treatment or other conservative therapy, in adults with nonspecific acute, subacute or chronic LBP. Among chronic nonspecific LBP patients, it was found that the pooled mean improvement for pain was 7.3 points (95% CI 3.7 – 10.9) and 2.5 points (95% CI 1.0 – 3.9) for function at earliest follow-up. It should be noted that the measurement was based on 100 point scale. With regard to subacute low back pain, the authors found some evidence of the effectiveness of a graded activity exercise program in an occupational setting. The evidence for other types of exercise therapy in other populations was found to be inconsistent. In acute low back pain, exercise therapy was as effective as either no treatment or other conservative treatments.
 
The second paper (2) attempted to identify particular exercise characteristics that decrease pain and improve function in adults with chronic nonspecific LBP.
The authors found compared to home exercise alone that:
- individually supervised programs improved pain scores by 5.9 points (out of 100 points) (95% CI 2.1-9.8)
- individually designed programs improved pain scores by 5.4 points (out of 100 points) (95% CI 1.3-9.5)
- supervised home exercise improved pain scores by 6.1 points (out of 100 points) (95% CI -0.2 – 12.4)
- group exercise improved pain scores by 4.8 points (out of 100 points) (95% CI 0.2-9.4)
 
Further, interventions that combined exercise with other conservative care had better results (pain improvement 5.1 points, 95% CI 1.8-8.4). As well, high dose exercise programs were better than low dose exercise programs (pain improvement 1.8 points, 95% CI -2.1 – 5.5). The authors identified stretching and strengthening as the most important components of the exercise programs in improving pain and function.
 
In both papers, the authors cautioned readers about the overall low quality of the published primary research, the heterogeneous outcome measures employed, the inconsistent and poor reporting, and the possibility of publication bias.

It should be noted that the authors, a priory, defined minimal clinically important difference as a 20 point improvement in pain or 10 point improvement in functioning outcomes.
It should be noted that these papers did not investigate the effect of physiotherapy or physiotherapists in treating nonspecific low back pain.
A complete critical appraisal of this topic is available from the Evidence Based Practice Group as part of our reply to the concerns raised by the Physiotherapy Association of BC.

 

Date posted: 2005/05/27
Topic: Spinal Cord Stimulation and Complex Regional Pain Syndrome: Results of two years' follow-up

Citation and Review:

Kemler MA, De Vet HC, Barendse GA, Van Den Wildenberg FA, Van Kleef M. The effect of spinal cord stimulation in patients with chronic reflex sympathetic dystrophy: two years' follow-up of the randomized controlled trial. Ann Neurol. 2004 Jan;55(1):13-8.

Recently, a two year follow-up of a randomized controlled trial (RCT) was published in the Annals of Neurology.  This is perhaps the only RCT on the application of spinal cord stimulators (SCS) among patients with complex regional pain syndrome (CRPS). The results of the two year follow-up were similar to the outcome at 6 months that was published by the same authors in 2000 and were employed by the EBPG in our assessment on SCS and CRPS.

The recent study showed that CRPS patients treated with SCS and physiotherapy had lower pain intensity (2.1 of 10 point scale) and better global perceived effects compared to patients who only received physiotherapy. However, in both studies there was no clinically significant improvement in functional status. It should be noted that 89 incidents of side effects, including paresthesia, pain/irritation, disturbed urination and replacement/reposition/reimplantation of the SCS, occurred during this period, 25% of which needed re-operation.  Thus, the outcomes of the two year follow-up on the application of SCS among CRPS patients should not change the conclusions provided in the EBPG review on SCS and CRPS.

 

Date posted: 2005/04/20
Topic: Acupuncture for low back pain

Citation and Review:

(1) Manheimer E, White A, Berman B, Forys K, Ernst E. Meta-analysis: acupuncture for low back pain. Ann Intern Med. 2005 Apr 19;142 (8):651-63. 

(2)  Furlan AD, van Tulder M, Cherkin D, Tsukayama H, Lao L, Koes B, Berman B. Acupuncture and dry-needling for low back pain: an updated systematic review within the framework of the Cochrane collaboration. Spine. 2005 Apr 15;30(8): 944-963
 
The two high quality, systematic reviews on acupuncture cited above were published in April 2005. Both investigated the effectiveness of acupuncture for treating low back pain (LBP).  Even though there were methodological differences, such as the literature search sources, strategies, inclusion and exclusion criteria (detailed appraisals will be available on our next update on Acupuncture), both reviews came to the similar conclusion that acupuncture is effective in reducing pain (compared to sham treatments) and improving function, either as a stand alone or adjunct treatment, in chronic LBP patients.  However, Furlan et al (2) pointed out that the effects only last for < 3 months. At present the effectiveness of acupuncture in treating acute LBP cannot be concluded due to the small number of trials in this area.

 

Date posted: 2005/04/06
Topic: Association Between Compensation Status and Outcome After Surgery:A Meta-analysis

Citation and Review:

Harris I, Mulford J, Solomon M, van Gelder JM, Young J. Association between compensation status and outcome after surgery: a meta-analysis. JAMA. 2005 Apr 6;293(13):1644-52.

This is a well-designed, executed and reported meta-analysis on the association between compensation status and outcome after surgery. Within the limitations of the study, the authors concluded that compensation status is associated with poor outcome after surgery. This effect is significant, clinically important and consistent.  Figure I and the table provided in the article are particularly informative.

 

Date posted: 2005/04/01
Topic: Subanesthetic Ketamine Infusion Therapy

Citation and Review:

Correll G.E., Maleki J., Gracely E.J., Muir J.J., Harbut R.E. Subanesthetic ketamine infusion therapy: a retrospective analysis of a novel therapeutic approach to complex regional pain syndrome. Pain Med. 2004 Sep;5(3):263-75
 
The outcome of this moderately-sized case report is interesting considering the nature of Complex Regional Pain Syndrome (CRPS) and the availability of effective treatment. However, the EBPG has some questions regarding this research and its implications:

  • The authors did not clearly describe the criteria/characteristics of the CRPS patients selected for this procedure.
  • Based on the amount of published literature, it seems that this procedure is still highly experimental.
  • Issues surrounding side effects need attention.
  • The ultimate outcome of this procedure (i.e. on quality of life or return to work/activities) is not available.

It is important to wait until published randomized controlled trials or at least prospective case series are available.

 

Date posted: 2005/04/01
Topic: Back Pain Europe (Part of the European Commission Research Directorate General)
Citation and Review:

(1) Van Tulder, Maurits et al. European guidelines for the management of acute nonspecific low back pain in primary care. Back Pain Europe. Available at: http://www.backpaineurope.org/web/files/WG1_Guidelines.pdf. Accessed April 1, 2005.

(2) Airaksinen, O. European guidelines for the management of chronic non-specific low back pain. Back Pain Europe. Available at: http://www.backpaineurope.org/web/files/WG2_Guidelines.pdf. Accessed April 1, 2005

(3) Burton, AK et al.European guidelines for prevention in low back pain. Back Pain Europe. November 2004. Available at: http://www.backpaineurope.org/web/files/WG3_Guidelines.pdf. Accessed April 1, 2005

Recently, Back Pain Europe developed and published three evidence-based guidelines. These guidelines provide direction in the management of acute and chronic non specific low back pain, as well as the prevention of low back pain.  The EBPG has analyzed these three documents and found them to be of high quality. The guidelines on the management of chronic non-specific low back pain (1) was discussed in a recent issue of the Back Pain Letter (v.20, n.3, March 2005). The guideline on the management of acute non-specific low back pain (2) is rather old (first draft: December 2000) however the information available is still accurate. The document on prevention of low back pain (3) is perhaps the most interesting. These papers also provide good executive summaries.

 

Date posted: 2005/04/01
Topic: Early Disability Risk Factors for Low Back Pain Assessed at Outpatient Occupational Health Clinics
Citation and Review:

Shaw WS, Pransky G, Patterson W, Winters T. Early disability risk factors for low back pain assessed at outpatient occupational health clinics. Spine. 2005 Mar 1;30(5):572-80.

he EBPG would like to draw attention to an article from the March 1, 2005 issue of Spine regarding predictors for return to work (or early disability risk factors). Despite some shortfalls in the methodology, the EBPG thinks the article provides good information on trying to reduce the number of chronic acute low back pain patients in order to facilitate return to work. Tables 4 and 5 are particularly informative. Even though the authors claim that their model had 74% sensitivity and 70% specificity, we'd suggest disregarding this data since it requires more validation.