Acupuncture research

Understanding and interpreting research can be difficult. Moreover, there are specific challenges when researching physical therapies such as acupuncture. If you are not familiar with the debates regarding acupuncture research, please take time to read the information below.  We believe this will support you in deciding whether or not acupuncture is something you would like to pursue.

The evidence pyramid

The evidence pyramid is a commonly used diagram which illustrates how different types of evidence relate to each other and their relative strengths. A simple version of the evidence pyramid can be seen in Figure 1. At the bottom of the pyramid sit the weaker types of evidence, expert opinion followed by observational studies. The stronger types of evidence are towards the top, randomised controlled trials (RCT) followed by systematic reviews.

Systematic reviews

Systematic reviews try to answer the question: does therapy X work for condition Y? Normally, systematic reviews will only include RCTs, the higher quality evidence, and exclude observational studies. They are called systematic because they should use a systematic method of searching to ensure all the relevant evidence is included. Ideally a systematic review will contain a meta-analysis where the results of the RCTs are combined to produce an overall result.

Systematic reviews should evaluate the ‘risk of bias’ from the included clinical trials. There are several things that may lead to bias. These include the methods used to randomise participants into different groups eg treatment or placebo group; and blinding, ensuring the participants cannot guess which group they are in. If there is a high risk of bias from the clinical trials included in a systematic review, this means it is difficult to draw a firm conclusion about whether the therapy is effective or not. Therefore, to draw a firm conclusion a systematic review must include a sufficient number of high-quality trials with an overall low risk of bias.

Clinical guidelines

Clinical guidelines provide recommendations to healthcare professionals regarding the different options for a particular condition. The National Institute for Health and Care Excellence (NICE) and The Scottish Intercollegiate Guidelines Network (SIGN) produce clinical guidelines in the UK. A systematic review is conducted to gather all the evidence. Clinical guidelines will often base their recommendations not just on whether a therapy is effective but also on a cost-benefit analysis.

Acupuncture is currently included in the following NICE guidelines:

• Headaches in over 12s: diagnosis and management (CG150)
• Chronic pain (primary and secondary) in over 16s: assessment of all chronic pain and management of chronic primary pain (CG193)

Systematic reviews of acupuncture

There are three main challenges when evaluating the evidence for acupuncture:

• availability of clinical trials
• the placebo
• quality of the acupuncture

Availability of clinical trials

The statement ‘there is no evidence that acupuncture is effective for condition Y’ can mean two different things. Clinical trials have been conducted and the results were negative. Alternatively, it means that no, or very few, high-quality clinical trials have been conducted.

Acupuncture research is dependent on charity and state funding, and conducting clinical trials is expensive. Consequently, for many conditions the available evidence is rather limited. The clinical trials are often small, involving less than 100 participants. This problem is reflected in the internationally renowned systematic reviews of the Cochrane Library. There are currently about 50 Cochrane reviews for acupuncture and various conditions. Many of these reviews, indicate that there is not sufficient evidence to draw a firm conclusion. However, it is important to remember this does not mean acupuncture is ineffective.

The placebo

A placebo should look and feel exactly like the real treatment, so that the patient does not know which treatment they are getting. Ideally, the person who administers the treatment should also not know whether it is a placebo or the real treatment. This is the meaning of ‘double-blinded’ clinical trial. Obviously, this is difficult for acupuncture because it requires inserting needles into people without them knowing whether the needle has been inserted or not. In addition, it means the acupuncturist would not know if the needle has been inserted.

Different methods have been used to blind the participants in acupuncture trials, these are normally referred to as sham acupuncture. Whether these sham acupuncture methods are inert or have therapeutic effects beyond the psychological is a controversy within acupuncture research. The BAcC view is that these are not inert interventions (for further reading see Appleyard et al 2014).

Sham acupuncture trials are single blinded because the acupuncturist knows whether sham or real acupuncture is being administered. This means even high-quality trials may be assessed as having a risk of bias. Acupuncture is not alone in this respect, placebo controls also difficult for other interventions such as surgery, exercise and talking therapies. In recent years, there have been calls for greater emphasis to be placed upon pragmatic research. Pragmatic research compares different interventions, for example, acupuncture vs medication or acupuncture vs physiotherapy.

Quality of the acupuncture

The acupuncture provided within some clinical trials would not be considered best practice by BAcC members. For example, sometimes the number of treatments is inadequate, only providing one or two treatments when really 10 would be more appropriate. Sometimes the acupuncture points used are not sufficient or appropriate.

Summary

The combined effect of sham acupuncture not being inert and inadequate acupuncture is to potentially reduce the effect size. In other words, clinical trials will tend to underestimate the effect of acupuncture compared to placebo.

Key systematic review

In recent years high-quality clinical trials investigating acupuncture have been conducted, particularly for chronic pain conditions. Therefore, there is evidence available, and the systematic reviews can draw firm conclusions. A systematic review of high-quality trials, Vickers et al 2018, involving over 20,000 adults with osteoarthritis, chronic headache or musculoskeletal pain (back, neck or shoulder) concluded:

• acupuncture was more effective than control for all pain conditions (pragmatic trials)
• acupuncture is not a placebo for treatment of chronic pain
• the effects persisted over time (15% reduction at one year)