Research Review By Dr. Demetry Assimakopoulos©

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Date Posted:

June 2016

Study Title:

Acupuncture for Neck Disorders

Authors:

Trinh K, Graham N, Irnich D et al

Author's Affiliations:

DeGroote School of Medicine/School of Rehabilitation Sciences/Centre for Evaluation of Medicine, McMaster University, Hamilton; Faculty of Medicine, University of Sydney, Sydney Australia; Physiotherapy Services, Sunnybrook/Women’s College Health Sciences Centre, North York, Ontario, Canada.

Publication Information:

Cochrane Database of Systematic Reviews 2016; Issue 5. Art. No.: CD004870. DOI: 10.1002/14651858.CD004870.pub4.

Background Information:

Neck pain is a very common musculoskeletal complaint, with a 12-month prevalence between 30-50% (1). Unfortunately, except perhaps for those of us in practice, neck pain recurs in 50-80% of people (2). The symptoms of neck pain vary, ranging from mild discomfort, to severe impairment. Neck pain can also be associated with headache, arm pain and neurological deficit, and has a substantial impact on health care costs (3).

Acupuncture is growing in popularity as an alternative to traditional therapies for neck pain. A prior 2006 Cochrane systematic review concluded that there was moderate-quality evidence that acupuncture can provide short-term neck pain relief (4). Unfortunately, the articles included in the abovementioned systematic review had small population samples, which might mask positive results. Luckily, more recent studies have used more modern and improved methods of assessment. This Cochrane review sought to summarize the most current scientific evidence on the effectiveness of acupuncture on acute, subacute and chronic neck pain.

Pertinent Results:

Twenty-seven trials (including a total of 5462 subjects) were included for review. The majority of the included studies had some variable risk of bias.

Acupuncture vs. Sham Acupuncture

Pain intensity (VAS): Moderate quality evidence suggests that acupuncture is beneficial for mechanical neck pain in the immediate-, short-, intermediate- and long-term post-treatment periods, compared to sham. The data examining the effect of acupuncture on pain intensity in the short-term were homogeneous and pooled for meta-analysis. The analysis concluded that acupuncture is favourable compared to sham at short-term follow-up. The data examining the effect of acupuncture on neck disability and quality of life were also pooled for meta-analysis, which was in favour of acupuncture.

Acupuncture vs. Inactive Treatment

Pain intensity (VAS): Of the studies included, acupuncture did not yield superior effects compared to inactive treatment in the immediate and long-term post-treatment periods. However, the authors concluded that moderate quality evidence exists in favour of acupuncture for the treatment of chronic mechanical neck pain in the short-term (1 day to 3 months). Interestingly, the authors initially wished to rate the evidence in favour of acupuncture in the short-term as high, because the majority of the GRADE criteria were met. They downgraded their rating to moderate however, because of small sample sizes used in the original studies. Only low-quality evidence exists for pain relief in the intermediate post-treatment period.

Disability and quality of life: There was no convincing evidence favouring acupuncture in the short-, intermediate- or long-term.

Acupuncture vs. Wait-list Control

Pain intensity (VAS) at short-term follow-up: One study was included for review, studying the effect of acupuncture on neck disorders with radiculopathy. The results favoured acupuncture for short-term pain relief. However, there was no evidence of improvement in the immediate post-treatment period.

Disability and Quality of life: One study was included for review, which assessed the effect of acupuncture on mechanical neck pain and disability (NDI) in the short-term. Acupuncture was superior to wait-list control. No convincing evidence favoured acupuncture in any other measures (i.e. SF-36).

A total of 14 studies reported adverse effects, such as bruising, increased pain, fainting, worsening of symptoms, local swelling and dizziness. No life threatening adverse effects were reported. A single, multi-centred trial reported that acupuncture is cost effective.

Clinical Application & Conclusions:

The authors found that acupuncture is more beneficial than sham for mechanical neck pain in the immediate post-treatment period. They also found that acupuncture is superior to sham and inactive treatments at short-term follow-up for pain intensity. Acupuncture is also superior to sham for pain intensity and ratings of disability in the short-term follow-up period, compared to patients assigned to a wait-list control. Unfortunately, these abovementioned effects are likely not sustainable over the long term. No serious complications have been reported.

Interestingly, the authors found that the acupuncture treatment dose was associated with treatment outcome. Ideally, treatment should consist of six or more acupuncture sessions. Included studies with fewer than 6 treatments failed to show favourable outcomes.

It is important to understand that the rigorous constraints inherent to performing RCTs in an attempt to measure a specific result might mask some of the effects of acupuncture observed in a clinical setting. Many of the effects reported by non-research clinicians are non-specific (things like: greater vitality, better sleep, return to activity, etc). In many instances, these non-specific benefits are deliberately not observed, in favour of rigorously studying a single outcome variable. Clinicians that are speculative of the effects from acupuncture should bear this in mind.

The notion that acupuncture can provide short-term analgesia is also important to recognize. Like many other physical treatments, acupuncture might provide temporary symptomatic relief, allowing the patient to return to normal activity, and take part in active or rehabilitative therapy.

Study Methods:

The authors included RCTs, quasi-RCTs and clinical controlled trials.

Inclusion criteria:
  • RCTs, quasi-RCTs, or clinical controlled trials examining the effect of acupuncture on neck pain. Studies involving manual, electrical, heat, laser and other forms of needle stimulation were included.
  • Participants had to be 18 years of age or older and suffering from: mechanical neck disorders (MND), whiplash associated disorders (WAD) 1 or 2, myofascial pain syndrome, degenerative changes, neck disorder with headaches, and/or neck disorder with radiculopathy/WAD 3.
  • Duration of neck pain could be acute (< 30 days), subacute (30-90 days) or chronic (> 90 days).
Exclusion criteria:
  • Neck disorders with definite or possible long tract signs, or neurological disease
  • Neck pain from pathological entities
  • Neck pain from fracture/dislocation
  • Coexisting headache where neck pain is not dominant
  • Mixed headache
The effect of acupuncture was measured at multiple time intervals, including the immediate post-treatment period (up to one day), short-term follow-up (1 day to 3 months), immediate-term follow-up (> 3 months to < 1 year) and long term follow-up (≥ 1 year).

A number of databases were electronically searched. Additional resources were screened through study-cited resources, professional communication and personal files. Chi-square tests were used to calculate agreement between investigators for study inclusion, selection and validity process before reaching consensus. Kappa statistics were used to measure author agreement. Each resource was rated as having high, low or unclear risk of bias.

Standardized mean differences/effect size, 95% confidence intervals, and risk ratios were used to summarize group description, interventions, outcomes, adverse effects and costs of care.

Random effects meta-analysis was performed where possible. If not possible, the authors described the results qualitatively in the context of clinically comparable trials.

The overall quality of the data was assessed using the GRADE criteria:
  • High quality evidence: findings consistent among at least 75% of RCTs with low risk of bias; consistent, direct and precise data; and no known or suspected publication bias.
  • Moderate quality evidence: one of the domains is not met. Further research is likely to have an important impact.
  • Low quality evidence: two domains are not met. Further research is very likely to have an important impact.
  • Very low quality evidence: three domains are not met. Very uncertain about the results.
  • No evidence: No RCTs addressed this outcome.

Study Strengths / Weaknesses:

Weaknesses:
  • Clinical heterogeneity in both the control and experimental groups in many cases prevented data pooling and meta-analysis.
  • Many studies did not report subject dropout rates.
  • The authors did not search many non-English language databases, and did not search Chinese databases beyond 2005.
Strengths:
  • Acupuncture treatments based on classical meridian points and dry needling were pooled together. There were not enough studies examining the effects of dry needling alone to separate the data. Past reviews have attempted to separate these two modalities.
  • The quality of acupuncture studies for neck pain has improved over time (especially since the last Cochrane review on this topic).
  • The authors used a comprehensive, librarian-assisted search of several databases.
  • Use of group consensus approach.
  • The authors were not members of a single profession, but practice in a variety of disciplines.
  • The data in some categories (listed above) were homogenous and meta-analyses were performed.

Additional References:

  1. Miller J, Gross A, D’Sylva J, et al. Manual therapy and exercise for neck pain: a systematic review. Manual Therapy 2010; 15: 334–54.
  2. Carroll LJ, Hogg-Johnson S, van der Velde G, et al. Course and prognostic factors for neck pain in the general population - results of the bone and joint decade 2000-2010 task force on neck pain and its associated disorders. Spine 2008; 33(4S): S75–82.
  3. Haldeman S, Carroll LJ & Cassidy JD. The empowerment of people with neck pain: Introduction - The bone and joint decade 2000-2010 task force on neck pain and its associated disorders. Spine 2008; 33(4S): S8–13.
  4. Trinh KV, Graham N, Gross AR, et al. Acupuncture for neck disorders. Cochrane Database of Systematic Reviews 2006; 3:1.