Acupuncture

We estimate that acupuncture and acupuncture-like interventions (acupressure, electrical or laser stimulation at acupuncture points etc.) have been investigated in more than 250 controlled clinical trials and in a much larger number of uncontrolled prospective studies and case series. The majority of the controlled clinical trials involve a comparison of "true" acupuncture with a "placebo" or "sham" acupuncture, thus investigating if there are specific effects. Finding an adequate "placebo" for acupuncture which is both indistinguishable (at least for patients and clinical evaluators) and inert is, however, a major problem and complicates the interpretation of such comparisons.

Good evidence from controlled trials for a clinical effect which is both superior to placebo and clinically relevant is up to now available only for the stimulation of the point P6 for nausea and vomiting [1], especially for postoperative vomiting. This study model has been used extensively not because of its relevance in the actual practice of acupuncture, but mainly because it is relatively easy to investigate (standardized treatment involving only one point, has a straightforward outcome measurement, and has a low likelihood of patients dropping out as observation periods can be kept very short).

Despite its widespread use - also in academic hospitals - the evidence for the effectiveness of acupuncture in the treatment of various painful conditions is not convincing [2-12]. Results are contradictory and the methodological quality of the majority of studies is at least partly inadequate. Nevertheless, acupuncture is used also in a large number of academic pain centres, claims positive results from clinical experience and observational studies, and is recommended by a number of experts and organisations including the World Health Organisation.

The results of controlled clinical trials for asthma treatment are also contradictory [13-16]. Regarding smoking cessation there is increasing evidence that "true" acupuncture has very little or no effect over "sham" acupuncture while the unspecific effects seem to be of similar size of other treatments (i.e. nicotine chewing gum) which have been shown to be superior to placebo [17-20]. This suggests that the placebo effect induced by acupuncture might be of a similar size as the combined unspecific and specific effects of another treatment. However, the available evidence is insufficient to allow a reliable assessment of this hypothesis which could be of major importance for acupuncture research. In stroke rehabilitation the addition of acupuncture to the ordinary treatment (compared with ordinary treatment alone) yielded some promising results [21]. In other conditions the number of trials is mostly insufficient to allow an interpretation.

A second major problem of acupuncture research (apart from the placebo problem discussed above) is the heterogeneous use of acupuncture. For example, apart from two studies from the same authors, all randomized trials of acupuncture for asthma used quite different treatment (and control) strategies. Randomized trials seem to be performed without ensuring that they reflect actual acupuncture practice and without pilot-testing. In consequence, it seems necessary that more research is done on the use of acupuncture in actual practice to collect reliable information on practice differences, patients, and outcomes under routine conditions.

The quality of clinical research in acupuncture is often unsatisfactory. This might be partly due to the lack of sponsoring. So far, we could not identify reviews which have systematically searched Chinese literature on acupuncture. According to non-systematic searches in that literature it seems that randomized trials are rare, but that there is a huge number of case series reporting extremely positive results. Very often, the methodology of these studies seems questionable. However, systematic reviews of uncontrolled trials have not been performed to our knowledge; this might be useful to collect more information about response rates.

Safety of acupuncture has been rarely investigated systematically. 126 documented cases of hepatitis associated with acupuncture due to the use of non-sterilised needles have been reported [22], mostly detected soon after the introduction of acupuncture into Western countries. Association with other infections has been reported, too [23]. Such complications can be avoided by the mandatory and exclusive use of properly sterilised needles. The most frequent severe traumatic complication resulting from acupuncture is pnothorax [23,24]. A total of 5 fatalities are documented in the literature [23]. In conclusion, from the available data acupuncture seems to be relatively safe but not free of risks.

Systematic reviews of acupuncture

First Author	Year	Condition	Comparison	Methods	Trialsinclud.	Conclusion
Vickers [1]	96	nausea	mainly sham	C,Q	29 RCTs	+
Patel [2]	89	chronic pain	mainly sham	Q,M	14 RCTs	(+)
ter Riet [3,4]	89/90	chronic pain	mainly sham	C,Q	51 CCTs	?
ter Riet [5]	89	migraine/tension headache	mainly sham	C,Q	10 CCTs	?
ter Riet [6]	89	facial pain	placebo	C,Q	2 RCTs	?
ter Riet [7]	89	back/neck pain	mainly sham	C,Q	22 CCTs	?
ter Riet [8]	89	rheumat arthritis	various	C,Q	3 CCTs	?
ter Riet [13]Kleijnen[14]	89 & 91	asthma	mainly sham	C,Q	13 CCTs	?
Linde [15,16]	96/97	asthma	mainly sham	C,Q	15 RCTs	?
ter Riet [17]	89/90	addiction	mainly sham	C,Q	22 CCTs	smoking -heroin ?alcohol ?
White[18,19]	96/97	smoking cessation	sham -other treatment	C,Q,M		(+)
Ernst [21]	96	stroke rehabilit.	standard		6 CCTs	(+)

Reviews on various treatments for a condition including acupuncture

Gabriel[10]	89	fibrositis	none		1 trial	?
Jacobs[11]	91	rheum. diseases	various		23 CCTs	?
Puett[12]	94	osteoarthritis	sham		2 RCTs	?
Law[20]	95	smoking cess.	various	M	8 RCTs	-
Volmink[9]	96	postherpetic neuralgia	Mock TENS	Q	1 RCT	-

C = comprehensive literature search
Q = systematic assessment of quality
M = quantitative meta-analysis