Roger Chou, MD; Laurie Hoyt Huffman, MS
Many nonpharmacologic therapies are available for treatment of low back pain.
To assess benefits and harms of acupuncture, back schools, psychological therapies, exercise therapy, functional restoration, interdisciplinary therapy, massage, physical therapies (interferential therapy, low-level laser therapy, lumbar supports, shortwave diathermy, superficial heat, traction, transcutaneous electrical nerve stimulation, and ultrasonography), spinal manipulation, and yoga for acute or chronic low back pain (with or without leg pain).
English-language studies were identified through searches of MEDLINE (through November 2006) and the Cochrane Database of Systematic Reviews (2006, Issue 4). These electronic searches were supplemented by hand searching of reference lists and additional citations suggested by experts.
Systematic reviews and randomized trials of 1 or more of the preceding therapies for acute or chronic low back pain (with or without leg pain) that reported pain outcomes, back-specific function, general health status, work disability, or patient satisfaction.
We abstracted information about study design, population characteristics, interventions, outcomes, and adverse events. To grade methodological quality, we used the Oxman criteria for systematic reviews and the Cochrane Back Review Group criteria for individual trials.
We found good evidence that cognitive-behavioral therapy, exercise, spinal manipulation, and interdisciplinary rehabilitation are all moderately effective for chronic or subacute (>4 weeks' duration) low back pain. Benefits over placebo, sham therapy, or no treatment averaged 10 to 20 points on a 100-point visual analogue pain scale, 2 to 4 points on the Rolandâ€“Morris Disability Questionnaire, or a standardized mean difference of 0.5 to 0.8. We found fair evidence that acupuncture, massage, yoga (Viniyoga), and functional restoration are also effective for chronic low back pain. For acute low back pain (<4 weeks' duration), the only nonpharmacologic therapies with evidence of efficacy are superficial heat (good evidence for moderate benefits) and spinal manipulation (fair evidence for small to moderate benefits). Although serious harms seemed to be rare, data on harms were poorly reported. No trials addressed optimal sequencing of therapies, and methods for tailoring therapy to individual patients are still in early stages of development. Evidence is insufficient to evaluate the efficacy of therapies for sciatica.
Our primary source of data was systematic reviews. We included nonâ€“English-language trials only if they were included in English-language systematic reviews.
Therapies with good evidence of moderate efficacy for chronic or subacute low back pain are cognitive-behavioral therapy, exercise, spinal manipulation, and interdisciplinary rehabilitation. For acute low back pain, the only therapy with good evidence of efficacy is superficial heat.
Appendix Table 1.
Appendix Table 2.
Appendix Table 3.
Appendix Table 4.
Appendix Table 5.
Appendix Table 6.
Appendix Table 7.
Appendix Table 8.
Appendix Table 9.
Appendix Table 10.
Appendix Table 11.
Appendix Table 12.
The In the Clinic® slide sets are owned and copyrighted by the American College of Physicians (ACP). All text, graphics, trademarks, and other intellectual property incorporated into the slide sets remain the sole and exclusive property of the ACP. The slide sets may be used only by the person who downloads or purchases them and only for the purpose of presenting them during not-for-profit educational activities. Users may incorporate the entire slide set or selected individual slides into their own teaching presentations but may not alter the content of the slides in any way or remove the ACP copyright notice. Users may make print copies for use as hand-outs for the audience the user is personally addressing but may not otherwise reproduce or distribute the slides by any means or media, including but not limited to sending them as e-mail attachments, posting them on Internet or Intranet sites, publishing them in meeting proceedings, or making them available for sale or distribution in any unauthorized form, without the express written permission of the ACP. Unauthorized use of the In the Clinic slide sets will constitute copyright infringement.
Jan M Bjordal
Inst. Physical Therapy, Bergen University College,
October 12, 2007
Why is a "fair" scientific grading higher for low level laser therapy than for other therapies?
In a recent systematic review of nonpharmacologic therapies for low back pain (LBP), the authors concluded that there is no evidence to support a recommendation for low level laser therapy (LLLT) (1). Although the review was largely based on previously published systematic reviews, no back-specific reviews were found for LLLT and four other therapies. For this reason a new literature search was undertaken which identified 5 randomized placebo-controlled trials and two comparative trials. The mechanisms behind LLLT have as yet not been fully understood. But recently it has been shown that all infrared wavelengths used in this review, reduce both inflammation and pain(2). In the current review, one small (n=20), medium quality trial (score 6/11) was reporting negative results. But as the authors in this trial used a dose of less than 10% of the other LLLT-trials, their negative findings are not surprising. All of the remaining 4 trials found significant results in favour of LLLT on relevant outcome measures such as pain, global improvement and Oswestry disability index (ODI). My own analyzes show that all combined outcomes were significantly better than placebo for the LLLT groups, and mean pain on VAS was reduced by 11.2 mm[1.2 "“ 22.3] even if the trial with insufficient dose (3) was included. For LLLT, the relative risk for global improvement was 2.55 [1.9 "“ 3-3] better than placebo and ODI was a mean 4.2 points better than placebo. It should be added that 3 of these trials yielded a high quality score(4-6), while the last trial just missed a "high" quality score by one criterion (5/11) (7). As for indirect evidence, an additional low quality trial found that LLLT was at least as effective as exercises (mean change 42mm vs 36 mm) for short-term pain relief (8). And the current review claims that exercises are moderately effective for subacute and chronic LBP. We can also add that a recent well-designed placebo-controlled LLLT-trial confirm the positive results of LLLT in subacute/chronic LBP for pain and disability measured by ODI (9), and that LLLT has recently been found effective in a Cochrane review for neck pain (10). Given the consistently positive results for adequate doses of LLLT, it is incomprehensible why LLLT evidence is rated as "poor". In comparison with other interventions for chronic/subacute LBP LLLT seems to have better evidence than yoga which was given a "fair" grading based on a single high quality with positive effects and two lower quality trials with largely non-significant results. And spinal manipulation was given a "fair" grading in acute LBP based on a single low quality trial in sacroiliac pain. Based on these comparisons I find the review conclusion for LLLT volatile and clearly deviating from the consistent positive evidence following from the published LLLT trials.
1. Chou, R. and L.H. Huffman, Nonpharmacologic therapies for acute and chronic low back pain: a review of the evidence for an American Pain Society/American College of Physicians clinical practice guideline. Ann Intern Med, 2007. 147(7): 492-504.
2. Bjordal, J.M., et al., Photoradiation in acute pain: a systematic review of possible mechanisms of action and clinical effects in randomized placebo-controlled trials. Photomed Laser Surg, 2006. 24(2): 158-68.
3. Klein, R.G. and B.C. Eek, Low energy laser treatment and exercise for chronic low back pain: double blind controlled trial. Arch Phys Med Rehab, 1990. 71(1): 34-7.
4. Soriano, F. and R. Rios, Gallium Arsenide Laser treatment of chronic low back pain: A prospective , randomized and double blind study. Laser Therapy, 1998. 10: 175-180.
5. Toya, S., et al., Report on a computer-randomized double blind clinical trial to determine the effectiveness of the GaAlAs (830nm) diode laser for attenuation in selected pain groups. Laser therapy, 1994. 6: 143-148.
6. Basford, J.R., C.G. Sheffield, and W.S. Harmsen, Laser therapy: a randomized, controlled trial of the effects of low-intensity Nd:YAG laser irradiation on musculoskeletal back pain. Arch Phys Med Rehabil, 1999. 80(6): 647-52.
7. Longo, L., A. Tamburini, and A. Monti, Treatment with 904 nm and 10600 nm laser of acute lumbago. Double-blind control laser J Eur Med Laser Ass, 1991. 3: 16-19.
8. Gur, A., et al., Efficacy of low power laser therapy and exercise on pain and functions in chronic low back pain. Lasers Surg Med, 2003. 32(3): 233-8.
9. Djavid, G.E., et al., In chronic low back pain, low level laser therapy combined with exercise is more beneficial than exercise alone in the long term: a randomised trial. Aust J Physiother, 2007. 53(3): 155-60.
10. Gross, A.R., et al., Conservative Management of Mechanical Neck Disorders: A Systematic Review. J Rheumatol, 2007.
Peninsula Medical School, Universities of Exeter and Plymouth
October 16, 2007
Risk of spinal manipulation
Chou et al(1) cite two of our reviews(2,3) stating that these and three further assessments "consistently found serious adverse events after serious manipulation (such as worsening lumber disc herniation or cauda equina syndrome) were very rare". Yet one of these articles(2) concludes that "the available data suggest that mild to moderate, transient adverse reactions occur in about 50% of patients after chiropractic spinal manipulation. Serious injuries are probably much rarer, but more conclusive studies are urgently needed", and the other one(3) states that "serious complications of spinal manipulation seem to be rare, whereas less serious adverse events occur frequently". The difference between Chou's "consistently very rare" and our attempts to express a high level of uncertainty about the risks is obvious.
The most worrying adverse events of spinal manipulation are not disc herniation or canda equina syndrome as Chou et al1 imply but cerebrovascular accidents.(2,3,4) Chou et al may have excluded these from their review on low back pain as these occur only after neck manipulation. This could be misleading as chiropractors, the profession using spinal manipulation more frequently than any other, consider the spine as an entity and will manipulate the upper spine, if they diagnose a subluxation in this area, even when patients consult them because of low back pain.
1. Chou R,.Hoffman LH. Non pharmacologic therapies for acute and chronic low back pain: A review of the evidence for an American Pain Society/American College of Physicians Clinical Practice Guideline. Ann Intern Med 2007;147:492-504.
2. Ernst E. Prospective investigations into the safety of spinal manipulation. J Pain Symptom Manage 2001;21:238-42.
3. Stevinson C,.Ernst E. Risks associated with spinal manipulation. Am J Med 2002;112:566-70.
4. Ernst E. Adverse effects of spinal manipulation: a systematic review. J R Soc Med 2007;100:330-8.
Brockbridge Therapy, Inc.
December 3, 2007
I thoroughly enjoyed reading Dr. Roger Chou, MD and Ms. Laurie Hoyt Huffman, MS' article, "Nonpharmacologic Therapies for Acute and Chronic Low Back Pain: A Review of the Evidence for an American Pain Society/American College of Physicians Clinical Practice Guideline", and found it very informative. I am writing this letter to express my concern regarding an impression I got about physical therapy from the article. In the article, the article search results were categorized into four major categories: spinal manipulation, massage and acupuncture; exercise therapy, yoga, and back schools; psychological therapies, interdisciplinary rehabilitation, and functional restoration; and physical therapies. Under the physical therapies category only a few passive modalities traditionally used by physical therapists and lumbar supports were listed. Unfortunately, this gives me and possibly other readers the impression that physical therapy is limited to the administration of passive modalities. Physical therapists, like me, are evidence based healthcare providers who are knowledgeable and skilled in the evaluation and management of low back pain. I traditionally screen my patients for symptoms associated with potentially serious medical conditions (e.g. cancer, cauda equine syndrome, etc.) that require medical referral; and for yellow flags (with validated and reliable outcome measures [e.g. Fear Avoidance Beliefs Questionnaire (FABQ) for worker's compensation patients with low back pain (Cleland, 2007)]) to determine if a different treatment approach (e.g. quota based exercise program [Kernan, 2007]) is indicated or if the expertise of a psycho-social expert would be beneficial.
My interventions for low back pain include educating my patients about their condition based on the information published in the Back Book, the use of spinal manipulation for patients with acute low back pain meeting a validated clinical prediction rule designed by Flynn et al (2002), and the use of manual therapy (e.g. mobilization) and various types of therapeutic exercises including (e.g. lumbar stabilization (Barr, 2007), extension oriented exercises (Browder, 2007), and flexion oriented exercises (Whitman, 2006) depending on the results of my physical examination. In a matter of fact, I and many of my colleagues don't use any of the modalities listed under "physical therapies" in the management of low back pain. Therefore, physical therapists do more than simply administer passive modalities. By integrating the best evidence into our practices we utilize the most effective interventions for our patients, which may include manual therapy (e.g. spinal manipulation), exercise, and or passive modalities just to name a few. If my impression is correct and readers of this article conclude that physical therapists simply administer passive modalities, then many patients, especially those with acute low back pain, may never be referred to physical therapy, and therefore may never receive appropriate and effective care in a timely manner. This would be extremely unfortunate. Sincerely, Dr. Sumesh Thomas, PT, DPT, OCS Brockbridge Therapy, Inc. Baltimore, MD
Barr KP, Griggs M, Cadby T. Lumbar stabilization: a review of core concepts and current literature, part 2. Am J Phys Med Rehabil. 2007 Jan;86(1):72-80.
Browder DA, Childs JD, Cleland JA, Fritz JM. Effectiveness of an Extension-Oriented Treatment Approach in a Subgroup of Subjects With Low Back Pain: A Randomized Clinical Trial. Phys Ther. 2007 Sep 25 [Epub ahead of print].
Cleland JA, Fritz JM, Brennan GP. Predictive validity of initial fear avoidance beliefs in patients with low back pain receiving physical therapy: is the FABQ a useful screening tool for identifying patients at risk for a poor recovery? Eur Spine J. 2007 Oct 10; [Epub ahead of print].
Flynn T, Fritz J, Whitman J, Wainner R, Magel J, Rendeiro D, Butler B, Garber M, Allison S. A clinical prediction rule for classifying patients with low back pain who demonstrate short-term improvements with spinal manipulation. Spine. 2002 Dec; 27(24): 2835-2843.
Kernan T, Rainville J. Observed outcomes associated with a quota- based exercise approach on measure of kinesiophobia in patients with chronic low back pain. JOSPT. 2007 Oct; 37(11):679-687.
Whitman JM, Flynn TW, Childs JD, Wainner RS, Gill HE, Ryder MG, Garber MB, Bennett AC, Fritz JM. A comparison between two physical therapy treatment programs for patients with lumbar spinal stenosis: a randomized clinical trial. Spine. 2006 Oct 15;31(22):2541-9.
Oregon Health & Science University
December 5, 2007
We thank the authors of the letters for their comments on our low back pain guideline (1) and evidence reviews (2, 3). Dr. Bjordal notes some methodologic concerns with our reviews. To clarify, we performed a systematic review of a broad range of low back pain topics, and when prior systematic reviews were available and of sufficient quality, we included them. The idea that new systematic reviews of the primary literature should always be conducted when developing clinical practice guidelines is both unsupported by any empirical evidence and if implemented could be a poor use of scientific resources (4). Guideline panels need relevant, current, high-quality reviews of the evidence; if existing reviews fulfill those criteria then it is wasteful to ignore them and conduct new reviews. We included systematic reviews published in or after the year 2000 and identified higher-quality reviews using a validated quality rating instrument (5, 6). Although systematic reviews should be updated, there is no compelling reason to ignore higher-quality Cochrane reviews (7) that met our criteria for inclusion and were "withdrawn" only because they did not meet an updating deadline, not because of methodological deficiencies or the publication of contradictory trials (8).
Dr. Bjordal suggests that we graded evidence for acetaminophen too positively. In his letter, Dr. Bjordal describes one trial as evaluating acute low back pain when it actually evaluated chronic low back pain (9). Otherwise, our descriptions of the evidence are similar (Appendix Tables 10 and 11 (2)). We agree that our evidence ratings for acetaminophen were generous given some inconsistency among trials of acute low back pain, and lack of direct evidence and small benefits for chronic low back pain. We re-rated evidence for acetaminophen for acute low back pain fair quality with moderate benefits, and for chronic low back pain fair quality with small benefits (see Correction). Because of acetaminophen's favorable safety profile compared to other pharmacologic therapies, these changes do not change our recommendation to consider it as a first-line option for pharmacologic therapy (1).
For NSAIDs, skeletal muscle relaxants, and benzodiazepines, Dr. Bjordal's focus on single outcomes from placebo-controlled trials reported in Cochrane reviews ignores much of the available evidence. Our assessments are based on both placebo and active-controlled trials, non- Cochrane systematic reviews, data on various outcomes related to pain, function, and global efficacy, and indirect evidence from patients with other pain conditions (Appendix Tables 10 and 11 (2)). We also evaluated consistency between trials and across higher-quality systematic reviews (10). In addition, post-hoc analyses, such as those presented by Dr. Bjordal, can be misleading and should be interpreted cautiously. For example, excluding trials based on small differences in quality scores is problematic given unpredictable associations between summary quality rating scores and estimates of effects (11). We did not report data on mean improvement in pain scores from a Cochrane review of NSAIDs because of substantial, unexplained heterogeneity (p<0.0001) (7).
As Dr. Bjordal surmised, we inverted relative risks (1/relative risk) for "˜no pain relief' with skeletal muscle relaxants and benzodiazepines (as reported in a Cochrane review (12)) to present results for a positive outcome (achieving pain relief) (2). However, this transformation was incorrect, as relative risks (unlike odds ratios) are not a symmetric statistic. We will correct the article to show original results as reported in the Cochrane review (see Corrections). This correction does not change any conclusions, but we thank Dr. Bjordal for noting this error.
We disagree with Dr. Bjordal's assertion that there is enough evidence to establish efficacy of low-level laser therapy (LLLT) and transcutaneous electrical nerve stimulation (TENS). In the case of LLLT, there is substantial diversity across trials in doses and types of laser, some inconsistency among higher-quality trials, and the possibility of publication bias. Our conclusion of insufficient evidence is similar to a recently published Cochrane review (13). For TENS, the highest quality placebo-controlled trial found no benefit in chronic low back pain (14). In addition, it is inappropriate to pool studies of disparate populations and therapies (TENS and neuromuscular stimulation), as proposed by Dr. Bjordal, and two of the trials proposed for pooling found no benefits on pain or function with TENS versus placebo (15, 16).
We disagree with Dr. Ernst that our conclusions regarding rare risk of serious adverse events with spinal manipulation are misleading or downplay the risk of cerebrovascular events (3). Our review deals with low back pain and treatment with lumbar spinal manipulation. There are no reports of cerebrovascular events following lumbar spine manipulation or in patients being treated for low back pain (17, 18). Cervical manipulation is not a subject of our review or practice guideline.
Dr. Bjordal suggests that recommendations for therapy favor pharmacologic over non-pharmacologic options (1). In fact, we recommend either type of therapy as options (Figure 1, Box 9 (1)), and strength of evidence and magnitude of benefits were graded similarly for several pharmacologic and non-pharmacologic therapies (Appendix Tables 5 and 6). However, recommendation 7 on non-pharmacologic therapies in general was graded "weak" because of relatively weak evidence for some suggested options (Appendix Tables 10 and 11 (3)), higher costs compared to first- line pharmacologic therapies, and less convenience (most non-pharmacologic options involving multiple provider visits). It would be appropriate to select a non-pharmacologic over pharmacologic therapy in patients who express such a preference, but the trade-offs should be discussed (19). Superficial heat is already recommended as a self-care option (Figure 2, Interventions box (1)).
Roger Chou, MD Oregon Health & Science University, Portland, Oregon
Paul Shekelle, MD, PhD Veterans Affairs Health Care System and RAND, Santa Monica, California
Amir Qaseem, MD, PhD, MHA The American College of Physicians, Philadelphia, Pennsylvania
Douglas K. Owens, MD, MS Veterans Affairs Palo Alto Health Care System, Palo Alto, and Stanford University, Stanford, California
1. Chou R, Qaseem A, Snow V, et al. Diagnosis and treatment of low back pain: A joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147:478 -491.
2. Chou R, Huffman LH. Medications for acute and chronic low back pain: a review of the evidence for an American Pain Society/American College of Physicians clinical practice guideline. Annals of Internal Medicine. 2007;147:505-514.
3. Chou R, Huffman LH. Non-pharmacologic therapies for acute and chronic low back pain: a review of the evidence for an American Pain Society/American College of Physicians Clinical Practice Guideline. Annals of Internal Medicine. 2007;147:492-504.
4. Silagy CA, Stead LF, Lancaster T. Use of systematic reviews in clinical practice guidelines: case study of smoking cessation. BMJ. 2001;323:833-836.
5. Jadad AR, McQuay HJ. Meta-analyses to evaluate analgesic interventions: a systematic qualitative review of their methodology. Journal of Clinical Epidemiology. 1996;49:235-243.
6. Oxman AD, Guyatt GH. Validation of an index of the quality of review articles. Journal of Clinical Epidemiology. 1991;44(11):1271-1278.
7. van Tulder MW, Schotten RJPM, Koes BW, Deyo RA. Non-steroidal anti -inflammatory drugs for low-back pain Cochrane Database of Systematic Reviews. 2000(2).
8. Shojania KG, Sampson M, Ansari MT, Ji J, Doucette S, Moher D. How quickly do systematic reviews go out of date? a survival analysis. Ann Intern Med. 2007;147:224-233.
9. Hickey RF, Hickey RF. Chronic low back pain: a comparison of diflunisal with paracetamol. New Zealand Medical Journal. 1982;95(707):312 -4.
10. GRADE Working Group. Grading quality of evidence and strength of recommendations. BMJ. 2004;328:1490-1494.
11. Juni P, Witschi A, Bloch R, Egger M. The hazards of scoring the quality of clinical trials for meta-analysis. JAMA. 1999;282:1054-1060.
12. van Tulder MW, Touray T, Furlan AD, Solway S, Bouter LM. Muscle relaxants for non-specific low-back pain Cochrane Database of Systematic Reviews. 2003(4).
13. Yousefi-Nooraie R, Schonstein E, Heidari K, et al. Low level laser therapy for nonspecific low-back pain. Cochrane Database of Systematic Reviews. 2007;2.
14. Deyo RA, Walsh NE, Martin DC, Schoenfeld LS, Ramamurthy S. A controlled trial of transcutaneous electrical nerve stimulation (TENS) and exercise for chronic low back pain. New England Journal of Medicine. 1990;322:1627-34.
15. Herman E, Williams R, Stratford P, Fargas-Babkak A, Trott M. A randomized controlled trial of transcutaneous electrical nerve stimulation (CODETRON) to determine its benefits in a rehabilitation program for acute occupational low back pain. Spine. 1994;19(5):561-568. 16. Moore SR, Shurman J. Combined neuromuscular electrical stimulation and transcutaneous electrical nerve stimulation for treatment of chronic back pain: a double-blind, repeated measures comparison. Arch Phys Med Rehabil. 1997;78:55-60.
17. Ernst E. Cerebrovascular complications associated with spinal manipulation. Physical Therapy Reviews. 2004;9(1):5-15.
18. Ernst E. Adverse effects of spinal manipulation: a systematic review. Journal of the Royal Society of Medicine. 2007;100:330-338.
19. Schunemann HJ, Jaeschke R, Cook DJ, et al. An official ATS statement: Grading the quality of evidence and strength of recommendations in ATS guidelines and recommendations. Am J Respir Crit Care Med. 2006;174:605-614.
We write to provide corrections to the recent joint guideline by the American College of Physicians and the American Pain Society on diagnosis and treatment of low back pain (1) and supporting evidence reviews (2, 3). In the original print version of the guideline, the target populations were described incorrectly (1). The word "not" was inadvertently dropped from a sentence that described populations that were excluded from the guideline. Children or adolescents with low back pain; pregnant women; patients with low back pain from sources outside the back (nonspinal low back pain), fibromyalgia or other myofascial pain syndromes, and thoracic or cervical back pain are not covered by the guideline. The online version of guideline has already been corrected.
In response to a letter to the editor (4) we re-reviewed the evidence on acetaminophen and believe we originally graded the evidence too positively in the guideline and evidence review (1, 2). However, our guideline recommendations remain the same. Acetaminophen for acute low back pain should be rated "˜fair' rather than "˜good' quality. Acetaminophen for chronic low back pain should be rated "˜fair' rather than "˜good' quality and magnitude of benefit "˜small' rather than "˜moderate' (Appendix Tables 5 and 6 in the guideline (1) and Appendix Tables 10 and 11 in the evidence review (2)). The Abstract/Data Synthesis section of the evidence review should read: "We found good evidence that NSAIDs, skeletal muscle relaxants (for acute low back pain), and tricyclic antidepressants (for chronic low back pain) are effective for pain relief"¦We also found fair evidence that acetaminophen, opioids, tramadol, benzodiazepines, and gabapentin (for radiculopathy) are effective for pain relief (2)." The Abstract/Conclusions section should read: "Medications with good evidence of short-term effectiveness for low back pain are NSAIDs, skeletal muscle relaxants (for acute low back pain), and tricyclic antidepressants (for chronic low back pain)." Similar changes should be applied to the Discussion section. As noted, these changes do not affect Recommendation 6 suggesting acetaminophen as an option for first-line pharmacologic therapy (1). This recommendation is based in large part on the safety profile of acetaminophen, when taken in appropriate dosages in patients without a contraindication.
Reference 62 in the evidence review on medications for low back pain is incorrect and should refer to a different trial by the same first author (5).
In the evidence review on medications, we inverted (calculated 1/relative risk) results for "not achieving pain relief" as reported in a Cochrane review (6) in order to report the likelihood of achieving pain relief. This conversion was incorrect because relative risk is not a symmetric statistic. The evidence review (2) will be corrected to state results as originally reported in the Cochrane review: for skeletal muscle relaxants, relative risks for not achieving pain relief 0.80 [CI, 0.71 to 0.89] at 2-4 days and 0.67 [0.13 to 3.44] at 5-7 days and relative risks for not achieving global efficacy 0.49 [CI, 0.25 to 0.95] at 2-4 days and 0.68 [CI, 0.41 to 1.13] at 5-7 days; and for benzodiazepines, relative risks for not achieving pain relief 0.71 [CI, 0.54 to 0.93] and for not achieving global efficacy 0.63 [CI, 0.42 to 0.97] at 8-14 days (6). Similarly, in the evidence review on non-pharmacologic therapies (3), results for a systematic review by Kool et al (7) on exercise therapy should state a relative risk of 0.73 [CI, 0.56 to 0.95] for not returning to work after 1 year . None of these corrections affect conclusions of the evidence reviews or guidelines.
All corrections have been applied to the online version of the articles.
Douglas K. Owens, MD, MS Veterans Affairs Palo Alto Health Care System, Palo Alto, and Stanford University, Stanford, California References
4. Bjordal JM, Lopes-Martin RAB, Klovning A, Roland PH, Slordal L. Overviews are methodically inferior to systematic reviews and contribute to myths of effective drugs. Annals Online. 17 Oct 2007.
5. Berry H, Bloom B, Hamilton EBD, Swinson DR. Naproxen sodium, diflunisal, and placebo int he treatment of chronic back pain. Ann Rheum Dis. 1982;41:129-132.
6. van Tulder MW, Touray T, Furlan AD, Solway S, Bouter LM. Muscle relaxants for non-specific low-back pain Cochrane Database of Systematic Reviews. 2003(4).
7. Kool J, de Bie R, Oesch P, Knusel O, van den Brandt P, Bachmann S. Exercise reduces sick leave in patients with non-acute non-specific low back pain: a meta-analysis. Journal of Rehabilitation Medicine. 2004;36(2):49-62.
Chou R, Huffman LH. Nonpharmacologic Therapies for Acute and Chronic Low Back Pain: A Review of the Evidence for an American Pain Society/American College of Physicians Clinical Practice Guideline. Ann Intern Med. 2007;147:492-504. doi: 10.7326/0003-4819-147-7-200710020-00007
Download citation file:
Published: Ann Intern Med. 2007;147(7):492-504.
Results provided by:
Copyright © 2017 American College of Physicians. All Rights Reserved.
Print ISSN: 0003-4819 | Online ISSN: 1539-3704
Conditions of Use
This PDF is available to Subscribers Only