Chiropractic spinal manipulation: what does the best evidence show?

Transcription

1 bs_bs_banner REVIEW Focus on Alternative and Complementary Therapies Volume 17(4) December The Author FACT 2012 Royal Pharmaceutical Society DOI /j x ISSN Chiropractic spinal manipulation: what does the best evidence show? Edzard Ernst Abstract Background The evidence of effectiveness of chiropractic is controversial. Objectives To summarise all Cochrane reviews of chiropractic spinal manipulation. Methods The Cochrane database was searched for all Cochrane reviews of chiropractic manipulation. Cochrane reviews with the terms chiropractic, manipulation or manual therapy in the title, abstract or keywords were considered. Protocols of reviews were excluded, as were studies that did not focus specifically on chiropractic spinal manipulation. Data extraction was performed by the author according to predefined criteria. Results Five Cochrane reviews were eligible for inclusion. Due to clinical and statistical heterogeneity, a meta-analysis was not possible and the findings of the reviews were discussed narratively. The five reviews related to the following conditions: low back pain, asthma, dysmenorrhoea and neck pain. Each review included between three and 39 primary studies. Cautiously positive conclusions emerged for low back pain and neck pain. For the two non-spinal conditions, the conclusions were negative. Conclusions Cochrane reviews, generally considered to be the most reliable evidence, provide limited evidence that chiropractic may be effective for low back and neck pain, but failed to support the use of chiropractic for non-spinal conditions. Keywords Chiropractic Cochrane database effectiveness spinal manipulation systematic review Background In recent decades, chiropractic has firmly established itself in the healthcare system of many countries, 1 and numerous clinical trials of chiropractic have been published. However, the results of these trials tend to be full of contradictions. In such situations, evaluating the totality of the evidence through systematic reviews (SRs) might be the best way forward to inform clinicians about the value of chiropractic for specific conditions. Many SRs of chiropractic have emerged but, confusingly, their evidence is far from uniform, even when dealing with the same clinical condition. 2 Overt contradictions often emerge, as is the case for the conclusions of SRs of headache, 3,4 fibromyalgia 5,6 and whiplash injury. 7,8 The more positive SRs are frequently authored by chiropractors, 3,6,7 while the more negative SRs tend to be published by independent experts. 4,5,8 Most chiropractors continue to make therapeutic claims that are not supported by good evidence 9,10 and tend to argue that those SRs that fail to generate positive conclusions are biased. It is therefore relevant to ask what the least biased SRs of chiropractic show. Several authors have demonstrated that 202

2 Review 203 Cochrane reviews tend to be superior to other reviews; they are more rigorous, more transparent, less biased and more up to date. 11 They might therefore be considered best. The aim of this article is to summarise the findings from Cochrane reviews of chiropractic spinal manipulation. Methods The Cochrane database was searched in April 2011 for SRs that had the term chiropractic, manipulation or manual therapy in their title, abstract or keywords. Articles were excluded if they referred to protocols only, were not specifically on chiropractic spinal manipulation (i.e. included chiropractic spinal manipulation amongst other forms of health care for a given condition), 12,13 or focused exclusively on non-manipulative interventions that might be occasionally used by chiropractors Reviews of combined chiropractic interventions (i.e. manipulation plus other physical therapies), were included. Reviews of massage therapy 25 and those focusing entirely on non-manipulative interventions typically done by mainstream doctors 26 were excluded. All articles were read in full and key data were extracted by the author according to predefined criteria (Table 1). A meta-analysis was considered but, due to clinical heterogeneity of the primary studies, this plan was abandoned. Results The search generated 163 hits. Most articles were excluded because they did not specifically focus on chiropractic spinal manipulations (Figure 1). Five systematic reviews met the inclusion criteria and were included Key data from these reviews are summarised in Table 1. The included SRs related to the following conditions: low back pain, 30,31 asthma, 27 dysmenorrhoea 28 and neck pain. 29 The reviews assessed the effectiveness of spinal manipulation, 28,29,31 any type of manual therapy 27 and any type of treatment administered by chiropractors. 30 As expected, all SRs were of outstanding methodological quality. Most were (co-) authored by chiropractors. None of the included SRs provided strong evidence that chiropractic spinal manipulation is an effective treatment for the conditions in question. For back and neck pain, the conclusions were cautiously positive For non-spinal conditions, the evidence failed to support the effectiveness of chiropractic 27,28 (Table 1). All SRs noted the poor quality of the primary studies. Discussion This analysis revealed that few Cochrane reviews of chiropractic were available (i.e. five compared to 4407 in total, as at 12 October, 2010). Reviews that have been published either failed to produce strong evidence in favour of chiropractic or were clearly negative. 27,28 Recent survey data suggest that many chiropractors use spinal manipulation to treat a wide range of non-spinal conditions. 10,32 The evidence for this is, however, far from compelling. 33 Similarly, most chiropractors make therapeutic claims that are not supported by good evidence. 9,10 The traditional basis for using spinal manipulation is the notion that subluxations exist and are of pathophysiological importance. This notion is, however, not based on sound data. 34,35 Thus, it is the author s opinion that chiropractic is biologically implausible and not supported by strong evidence from Cochrane reviews. Considering that the best available evidence is unconvincing or negative, 27,28 and that chiropractic manipulations are by no means free of risks, 36 chiropractors should either produce convincingly positive evidence or stop promoting and employing unproven approaches to health care. A recent survey of 487 North American orthopaedic surgeons seems to agree with this view: The majority of respondents agreed that chiropractors provide effective therapy for some musculoskeletal complaints, but disagreed that they could provide effective care for non-musculoskeletal conditions or for postsurgical rehabilitation. The majority was also of the opinion that chiropractors provide unnecessary treatment, engage in overly-aggressive marketing, breed dependency in patients on shortterm symptomatic relief, and do not treat in accordance with evidence-based practices. 37 This analysis had several limitations. The paucity of Cochrane reviews was disappointing. Two of the reviews 27,28 included only three RCTs with a small total sample size. The conditions treated were highly diverse. Many of the primary studies included in the SRs were of poor quality. Collectively, these drawbacks limit the conclusions of this review. In order to move this field of inquiry forward, we need more high-quality research. Several clinical trials of chiropractic have recently been supported by the US National Centre for Complementary and Alternative Medicine (NCCAM). Such independently funded studies seem a step in the right direction. Unfortunately, a recent analysis of these data showed that several RCTs failed to report adverse effects and the majority was not described in sufficient detail to allow replication. 38 This might serve as a reminder

3 204 Focus on Alternative and Complementary Therapies December (4) Table 1 Cochrane reviews of chiropractic spinal manipulation First author (year) Aim of review (quote) Treatment Condition Number of trials (total sample size) Authors conclusion (quote) Hondras evaluate the evidence for the (2005) 27 effects of manual therapies for bronchial asthma Proctor determine the safety and (2006) 28 efficacy of spinal manipulative interventions Gross (2010) 29 assess if manipulation or mobilisation improves pain Walker determine the effects of (2010) 30 combined chiropractic interventions Rubinstein To assess the effects of SMT for (2011) 31 chronic low back pain Any type of manual therapy Asthma Three RCTs (156 patients; two RCTs of chiropractic manipulation) There is insufficient evidence to support the use of manual therapies for patients with asthma Any type of SMT Dysmenorrhoea Three RCTs (213 patients) There is no evidence to suggest that spinal manipulation is effective Any type of SMT Neck pain 27 RCTs (1522 patients) Cervical manipulation and mobilization...may provide immediate or short-term change Any type of therapy used by chiropractors Any type of SMT Chronic low back pain Low back pain 12 RCTs (2887 patients) Combined chiropractic interventions slightly improved pain and disability in the short-term and pain in the medium-term for acute and subacute LBP. However, there is currently no evidence that supports or refutes that these interventions provide a clinically meaningful difference for pain or disability in people with LBP when compared to other interventions. Future research is very likely to change the estimate of effect and our confidence in the results 26 RCTs High quality evidence suggests that there is no clinically relevant difference between SMT and other interventions for reducing pain and improving function in patients with chronic low-back pain. Determining cost-effectiveness of care has high priority. Further research is likely to have an important impact on our confidence in the estimate of effect in relation to inert interventions and sham SMT, and data related to recovery LBP, low back pain; SMT, spinal manipulation therapy.

4 Review hits found with initial search Figure 1 Five reviews included that clinical research in this area has to be rigorous in order to be meaningful. Conclusion In conclusion, the best available evidence failed to provide strong support for chiropractic as a treatment for neck or back pain, and provided no support for the use of chiropractic for non-spinal conditions. External funding None. Excluded (n = 158): - study protocol (n = 32) - not specifically on chiropractic (n = 36) - not chiropractic manipulation (n = 90) Flow chart of included systematic reviews. Conflict of interest None declared. References 1 Coulter ID, Shekelle PG. Chiropractic in North America: a descriptive analysis. J Manipulative Physiol Ther 2005; 28: Ernst E. Chiropractic: a critical evaluation. J Pain Symptom Manage 2008; 35: Bronfort G, Assendelft WJ, Evans R et al. Efficacy of spinal manipulation for chronic headache: a systematic review. J Man Phys Ther 2001; 24: Astin JA, Ernst E. The effectiveness of spinal manipulation for the treatment of headache disorders: a systematic review of randomized clinical trials. Cephalalgia 2002; 22: Ernst E. Chiropractic treatment for fibromyalgia: a systematic review. Clin Rheumatol 2009; 28: Schneider M, Vernon H, Ko G et al. Chiropractic management of fibromyalgia syndrome: a systematic review of the literature. J Manipulative Physiol Ther 2009; 32: Shaw L, Descarreaux M, Bryans R et al. A systematic review of chiropractic management of adults with Whiplash-Associated Disorders: recommendations for advancing evidence-based practice and research. Work 2010; 35: Ernst E. Chiropractic spinal manipulation for whiplash injury? A systematic review of controlled clinical trials. Focus Altern Complement Ther 2009; 14: Ernst E, Gilbey A. Chiropractic claims in the Englishspeaking world. N Z Med J 2010; 123: Christensen MG, Hyland JK. Practice Analysis of Chiropractic A project report, survey analysis and summary of the practice of chiropractic within the United States. Greely, CO: National Board of Chiropractic Examiners, Olsen O, Middleton P, Ezzo J et al. Quality of Cochrane reviews: assessment of sample from BMJ 2001; 323: Smith CA, Collins CT, Cyna AM, Crowther CA. Complementary and alternative therapies for pain management in labour. Cochrane Database Syst Rev 2006; 4: CD Handoll HH, Madhok R. Conservative interventions for treating distal radial fractures in adults. Cochrane Database Syst Rev 2003; 2: CD Verhagen AP, Karels CC, Bierma-Zeinstra SMA et al. [Withdrawn] Ergonomic and physiotherapeutic interventions for treating work-related complaints of the arm, neck or shoulder in adults. Cochrane Database Syst Rev 2009; 3: CD van Duijvenbode I, Jellema P, van Poppel M, van Tulder MW. Lumbar supports for prevention and treatment of low back pain. Cochrane Database Syst Rev 2008; 2: CD Teixeira LJ, Soares BGDO, Vieira VP, Prado GF. Physical therapy for Bell s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev 2008; 12: CD States RA, Pappas E, Salem Y. Overground physical therapy gait training for chronic stroke patients with mobility deficits. Cochrane Database Syst Rev 2009; 3: CD Schaafsma F, Schonstein E, Whelan KM et al. Physical conditioning programs for improving work outcomes in workers with back pain. Cochrane Database Syst Rev 2010; 1: CD Brosseau L, Pelland L, Casimiro L et al. Electrical stimulation for the treatment of rheumatoid arthritis. Cochrane Database Syst Rev 2002; 2: CD Mason DL, Dickens VA, Vail A. Rehabilitation for hamstring injuries. Cochrane Database Syst Rev 2007; 1: CD Katalinic OM, Harvey LA, Herbert RD et al. Stretch for the treatment and prevention of contractures. Cochrane Database Syst Rev 2010; 9: CD

5 206 Focus on Alternative and Complementary Therapies December (4) 22 Khadilkar A, Odebiyi DO, Brosseau L, Wells GA. Transcutaneous electrical nerve stimulation (TENS) versus placebo for chronic low-back pain. Cochrane Database Syst Rev 2008; 4: CD Haines T, Gross A, Burnie SJ et al. Patient education for neck pain with or without radiculopathy. Cochrane Database Syst Rev 2009; 1: CD Graham N, Gross A, Goldsmith CH et al. Mechanical traction for neck pain with or without radiculopathy. Cochrane Database Syst Rev 2008; 4: CD Haraldsson B, Gross A, Myers CD et al. Massage for mechanical neck disorders. Cochrane Database Syst Rev 2006; 3: CD Krul M, van der Wouden JC, van Suijlekom-Smit LWA, Koes BW. Manipulative interventions for reducing pulled elbow in young children. Cochrane Database Syst Rev 2009; 4: CD Hondras MA, Linde K, Jones AP. Manual therapy for asthma. Cochrane Database Syst Rev 2005; 2: CD Proctor ML, Hing W, Johnson TC, Murphy PA. Spinal manipulation for dysmenorrhoea. Cochrane Database Syst Rev 2006; 3: CD Gross A, Miller J, D Sylva J et al. Manipulation or mobilisation for neck pain. Cochrane Database Syst Rev 2010; 1: CD Walker BF, French SD, Grant W, Green S. Combined chiropractic interventions for low-back pain. Cochrane Database Syst Rev 2010; 4: CD Rubinstein SM, van Middelkoop M, Assendelft WJ et al. Spinal manipulative therapy for chronic low-back pain. Cochrane Database Syst Rev 2011; 2: CD Alcantara J, Ohm J, Kunz D. The chiropractic care of children. J Altern Complement Med 2010; 16: Bronfort G, Haas M, Evans R et al. Effectiveness of manual therapies: the UK evidence report. Chiropr Osteopat 2010; 18: Mirtz TA, Morgan L, Wyatt LH, Greene L. An epidemiological examination of the subluxation construct using Hill s criteria of causation. Chiropr Osteopat 2009; 17: Homola S. Real orthopaedic subluxations versus imaginary chiropractic subluxations. Focus Altern Complement Ther 2010; 15: Miley ML, Wellik KE, Wingerchuk DM, Demaerschalk BM. Does cervical manipulative therapy cause vertebral artery dissection and stroke? Neurologist 2008; 14: Busse JW, Jacobs C, Ngo T et al. Attitudes toward chiropractic: a survey of North American orthopedic surgeons. Spine 2009; 34: Ernst E, Posadzki P. An independent review of NCCAM-funded studies of chiropractic. Clin Rheumatol 2011; 30: Edzard Ernst, MD, PhD, FMedSci, FSB, FRCP, FRCPEd, Editor-in-chief of FACT, Emeritus Professor, Peninsula Medical School, University of Exeter, Veysey Building, Salmon Pool Lane, Exeter, EX2 4SG, UK. edzard.ernst@pms.ac.uk