Acupuncture treatment for pain: systematic review of randomised clinical trials with acupuncture, placebo acupuncture, and no acupuncture groups

The authors of this review stated that their aim was ‘to study the
analgesic effect of acupuncture and placebo acupuncture’. There could be
at least three different ways to operationalise these aims as research
questions. Each requires a different study method and analysis. The
authors seem to intend to address parts of each question, and so their
methodology may not be entirely appropriate.

1. Is acupuncture a clinically relevant treatment for chronic pain?
The way to address this question would be to compare the normal practice
of acupuncture with usual care, and with other existing treatments. There
is no reason to limit the evidence to three arm studies. And there is no
reason to simply compare acupuncture and ‘placebo’ acupuncture, as done
here: the clinical impact of every physical treatment incorporates both
psychological and physical components, which are not delivered separately.
We would get more of an impression of the clinical value of acupuncture if
we combined the results of the two analyses (acupuncture vs ‘placebo’, and
‘placebo’ vs usual care). This gives an overall acupuncture treatment
effect of about 14mm, which is hardly large but may meet the authors’
definition of ‘clinically relevant’. Thus, the analysis used in the
review seems inappropriate for the conclusion they made, that the
analgesic effect of acupuncture seems to lack clinical relevance.

2. Is acupuncture just a placebo? The authors seem interested in two
parts to this question: whether needles have neurophysiological effects of
their own, separate from their psychological effects; and, what is the
size of the psychological (placebo) effect of acupuncture. At first sight,
it seems appropriate to compare acupuncture with ‘placebo’ acupuncture.
However, in the Introduction the authors summarise the neurophysiology of
acupuncture with the statement: ‘Studies indicate that penetration of a
needle through the skin, whether at an acupuncture point or not, has
physiological effects’. Unfortunately, this sentence renders most of their
data irrelevant: if needles inserted at non-acupuncture points have
physiological effects, they are not a ‘placebo’ and studies using them
cannot be included. Only two trials included in the review used needles
that did not penetrate the skin and might be placebo, though there is some
doubt about whether even non-penetrating needles are completely inert.[1
2] This placebo control problem in acupuncture research is well recognised
and unfortunately not overcome by the methodology used here. So the study
had little chance of providing any conclusions about whether acupuncture
is just a ‘placebo’, or about the size of the effect of ‘placebo’
acupuncture.

3. Is acupuncture a panacea for pain? This seems to be the authors’
main question, expressed mostly clearly in the Discussion and in the Rapid
Responses as ‘an effect on pain in general’. This phrase was used to
justify the inclusion of studies in different pain conditions, such as
osteoarthritis, fibromyalgia, procedural pain, migraine and postoperative
pain. However, it is well accepted that there are several different types
of pain (e.g. some do not respond well to morphine) which need different
treatments.[3] So the hypothesis that acupuncture is a panacea for pain is
surprising and not really scientifically based. It requires some reference
to justify it, but none is given. No acupuncturist of my acquaintance has
ever made this claim, nor can I readily find it in a peer reviewed
publication. I suppose there may be some people on the fringes of
acupuncture with little clinical experience of real patients who might say
such a thing out of ignorance or innocence, but they make a rather soft
target. The methodology may be appropriate for addressing this question,
but the question seems rather pointless. It may be that the authors are
concerned about the exaggerated claims that are sometimes made for
acupuncture, which could be a significant problem. If so it would seem
that the appropriate methodology would not be meta-analysis, but
regulation.

I have only outlined three possible research questions, and there may
be others that the authors were really addressing. It would be interesting
to hear from them, so that we can judge how this work stands in relation
to the cautious effort to build up the primary evidence on whether or not
acupuncture can contribute to the wellbeing of patients, as exemplified by
the journal Acupuncture in Medicine. [4]

References

1. Lund I, Lundeberg T. Are minimal, superficial or sham acupuncture
procedures acceptable as inert placebo controls? Acupunct. Med
2006;24(1):13-15.

2. Lund I, Naslund J, Lundeberg T. Minimal acupuncture is not a valid
placebo control in randomised controlled trials of acupuncture: a
physiologist's perspective. Chinese Medicine 2009;4(1):1.

3. Woolf CJ, Decosterd I. Implications of recent advances in the
understanding of pain pathophysiology for the assessment of pain in
patients. Pain 1999;Suppl 6:S141-7.

4. White A, Med EBoA. Western medical acupuncture: a definition.
Acupunct Med 2009;27(1):33-5.

Competing interests:
The author has received fees for lecturing on acupuncture and is paid as the editor in chief of Acupuncture in Medicine, which aims to provide an unbiased approach to the evidence on acupuncture’s place in health care using a western scientific approach