Research Review By Dr. Jeff Muir©

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Date Posted:

June 2019

Study Title:

Benefits and harms of spinal manipulative therapy for the treatment of chronic low back pain: systematic review and meta-analysis of randomised controlled trials

Authors:

Rubinstein SM, de Zoete A, van Middelkoop M, Assendelft WJJ, de Boer MR, van Tulder MW

Author's Affiliations:

Department of Health Sciences, Faculty of Science, Vrije Universiteit Amsterdam, Netherlands; Department of General Practice, Erasmus Medical Centre, Rotterdam, Netherlands; Department of Primary and Community Care, Radboud University Medical Centre, Nijmegen, Netherlands; Department of Physiotherapy & Occupational Therapy, Aarhus University Hospital, Aarhus, Denmark.

Publication Information:

British Medical Journal (BMJ) 2019; 364: l689. doi: 10.1136/bmj.l689

Background Information:

Low back pain remains a significant healthcare problem, one that challenges patients, clinicians and policymakers alike. Spinal manipulative therapy (SMT) is widely used as a mainstay treatment for low back pain and has been the subject of several randomized, controlled trials which have been summarized in earlier reviews by the authors and have acted as a basis for recommendations in current clinical practice guidelines (1-4).

Despite the existing evidence and support within clinical guidelines, recommendations regarding the use of SMT for low back pain are not without dispute (5). While considered a front-line treatment in some jurisdictions (2), SMT is also viewed as a complimentary treatment amongst a broader treatment package in others (4). Recent guideline summaries have indeed recommended SMT as a second line therapy (6).

The purpose of the current review is to update an earlier Cochrane review by the same authors (7), which found no clinically relevant difference between SMT and other effective interventions for low back pain. The review sought to examine the effectiveness of SMT on pain relief and improvement of function at the short, intermediate and long-term follow-ups.

Pertinent Results:

Included Studies:
47 trials were eligible for inclusion, 21 of which were not included in the previous review. 9211 total patients were included, with sample sizes in individual trials ranging from 21 to 1334. The average age of participants was 35-60 yrs. Practitioners varied and included chiropractors, physical/manual therapists, osteopaths, medical doctors or naturopaths. Treatment techniques involved were primarily high velocity, low amplitude thrust (HVLA), low velocity, low amplitude thrust (LVLA), passive movement techniques, or a combination of HVLA and LVLA.

Risk of Bias Assessment:
3 studies were excluded due to significant flaws and high risk of bias. Adequate sequence generation and allocation procedures were suspect in over half of eligible studies; only 5 studies attempted to blind participants.

Outcomes:
  1. SMT vs. Recommended Interventions: Moderate quality evidence suggested that SMT was significantly better than recommended interventions at 6 months but not at 1 month or 12 months, although the effect size was not clinically relevant. Moderate quality evidence also indicated that back specific functional status was improved at 1 month, but not at 6 or 12 months, although this improvement was not significant.
  2. SMT vs. Non-recommended Interventions: High quality evidence indicated that SMT resulted in a small, statistically significant effect, although it was not clinically significant. Moderate and low-quality evidence indicated that SMT resulted in not-significant improvements at 6 and 12 months, respectively. Small to moderate improvements in back specific functional status were noted with SMT at 1, 6 and 12 months.
  3. SMT vs. Sham SMT: SMT was not shown to improve pain when compared with sham SMT at 1, 6 or 12 months, although the evidence was low to very low quality for this outcome. SMT demonstrated a moderate to strong improvement over sham SMT with respect to back specific functional status, although no improvement was noted at 6 or 12 months.
  4. SMT as Adjunctive Therapy: When used as an adjunctive therapy, SMT demonstrated a significant but not clinically relevant improvement in both pain and back specific functional status at 1 and 12 months, but not at 6 months.
Secondary Analyses
No significant difference was noted between HVLA and LVLA SMT at 1 or 6 months; no data was available at 12 months. One study compared Maitland mobilization with Mulligan mobilization and noted no significant difference between the two techniques.

Adverse Events:
Adverse events were reported in approximately half of eligible studies, although recording of adverse events in various studies was unclear, which the authors suggest might make the data unreliable. One study suggested no increased risk of adverse events when comparing SMT with sham SMT. Two studies reported on serious adverse events as part of Data Safety Monitoring Board requirements, with 1 identifying no adverse events and 1 study noting 1 adverse event.

Clinical Application & Conclusions:

The authors of this important paper made several conclusions. For clinicians, the value of SMT as a treatment for low back pain is highlighted, as is the relatively low rate of adverse events observed in the pooled analysis. For policymakers, the authors note that, while they did not search for reviews with economic considerations, they cite two recent systematic reviews (8, 9) which indicate that SMT is a cost-effective treatment for low back pain.

Overall, the authors conclude:
  1. ”In the treatment of chronic low back pain in adults, moderate quality evidence suggests that spinal manipulative therapy (SMT) results in similar outcomes to recommended therapies for short, intermediate, and long term pain relief as well as improvement in function.”
  2. SMT results in clinically better effects in the short-term with respect to functional status when compared with non-recommended therapies, sham SMT or when SMT is used as an adjunctive therapy. The evidence is varied regarding pain relief in this comparison.

Study Methods:

The authors followed the PRISMA guidelines for their review and registered the protocol with the Cochrane Collaboration. Several databases were searched: Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Medline In-Process and Other Non-Indexed Citations, Embase, CINAHL, Physiotherapy Evidence Database (PEDro), Index to Chiropractic Literature, and PubMed.

Study Eligibility:
  • Randomized studies only,
  • Adult population (> 18 yrs); > 50% of population had duration of pain of > 3 months,
  • Treatment: SMT alone or part of a package of care.
Primary Analyses:
  • SMT was compared to: 1) recommended therapies; 2) non-recommended therapies; 3) placebo/sham SMT; or 4) SMT as an adjunctive therapy.
Outcome Measures:
  • Pain intensity
  • Pain specific functional status
Two authors were responsible for data extraction. Risk of bias was assessed using the Cochrane Back and Neck Review Group criteria. Outcomes were assessed at 1, 3, 6 and 12-months post-randomization. Clinical relevance was defined as small (mean difference < 10% of the scale), medium (10-20%) or large (> 20% mean difference). Quality of evidence was evaluated using GRADE. Standard meta-analytic tests for heterogeneity (Q-value and I2 statistic) were utilized.

Study Strengths / Weaknesses:

Strengths:
  • Strong, comprehensive search criteria.
  • Clinically relevant and comprehensive treatment interventions and comparators.
  • Strong statistical analysis plan.
Weaknesses:
  • Heterogeneity among studies limits veracity of pooled data.
  • Limited number of studies with low risk of bias.
  • Vague details regarding research team and/or treatment team composition and lack of disclosures limits the ability to rule out conflicts of interest.

Additional References:

  1. Airaksinen O, Brox JI, Cedraschi C, et al, COST B13 Working Group on Guidelines for Chronic Low Back Pain. Chapter 4. European guidelines for the management of chronic nonspecific low back pain. Eur Spine J 2006; 15(Suppl 2): S192-300. doi:10.1007/s00586-006-1072-1.
  2. Qaseem A, Wilt TJ, McLean RM, Forciea MA. Clinical Guidelines Committee of the American College of Physicians. Noninvasive Treatments for Acute, Subacute, and Chronic Low Back Pain: A Clinical Practice Guideline From the American College of Physicians. Ann Intern Med 2017; 166: 514-30. doi:10.7326/M16-2367.
  3. Bons SCS, Borg MAJP, Van den Donk M, et al. NHG guideline for aspecific low-back pain, 2017. www.nhgorg/standaarden/samenvatting/aspecifieke-lagerugpijn#idp23613872.
  4. NICE guideline. Low back pain and sciatica in over 16s: assessment and management. www.nice.org.uk/guidance/NG59/chapter/Recommendations#non-invasive-treatments-for-low-back-pain-andsciatica, 2016.
  5. Koes BW, van Tulder M, Lin CW, Macedo LG, McAuley J, Maher C. An updated overview of clinical guidelines for the management of nonspecific low back pain in primary care. Eur Spine J 2010; 19: 2075-94. doi:10.1007/s00586-010-1502-y.
  6. Foster NE, Anema JR, Cherkin D, et al. Prevention and treatment of low back pain: evidence, challenges, and promising directions. Lancet 2018; 391(10137): 2368-2383.
  7. Rubinstein SM, van Middelkoop M, Assendelft WJJ, de Boer MR, van Tulder MW. Spinal manipulative therapy for chronic low-back pain. Cochrane Database Syst Rev 2011; (2): CD008112.
  8. Andronis L, Kinghorn P, Qiao S, Whitehurst DG, Durrell S, McLeod H. Cost-Effectiveness of Non-Invasive and Non-Pharmacological Interventions for Low Back Pain: a Systematic Literature Review. Appl Health Econ Health Policy 2017; 15: 173-201. doi:10.1007/s40258-016-0268-8.
  9. Michaleff ZA, Lin CW, Maher CG, van Tulder MW. Spinal manipulation epidemiology: systematic review of cost effectiveness studies. J Electromyogr Kinesiol 2012; 22: 655-62. doi:10.1016/j. jelekin.2012.02.011.