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Systematic reviews of complementary therapies - an annotated bibliography. Part 1: Acupuncture

  • Klaus Linde1, 2Email author,
  • Andrew Vickers3,
  • Maria Hondras4,
  • Gerben ter Riet5, 6,
  • Johannes Thormählen1,
  • Brian Berman7 and
  • Dieter Melchart1
BMC Complementary and Alternative MedicineBMC series ¿ open, inclusive and trusted20011:3

DOI: 10.1186/1472-6882-1-3

Received: 22 March 2001

Accepted: 16 July 2001

Published: 16 July 2001

Abstract

Background

Complementary therapies are widespread but controversial. We aim to provide a comprehensive collection and a summary of systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, homeopathy). This article is dealing with acupuncture. Potentially relevant reviews were searched through the register of the Cochrane Complementary Medicine Field, the Cochrane Library, Medline, and bibliographies of articles and books. To be included articles had to review prospective clinical trials of acupuncture; had to describe review methods explicitly; had to be published; and had to focus on treatment effects. Information on conditions, interventions, methods, results and conclusions was extracted using a pretested form and summarized descriptively.

Results

From a total of 48 potentially relevant reviews preselected in a screeening process 39 met the inclusion criteria. 22 were on various pain syndromes or rheumatic diseases. Other topics addressed by more than one review were addiction, nausea, asthma and tinnitus. Almost unanimously the reviews state that acupuncture trials include too few patients. Often included trials are heterogeneous regarding patients, interventions and outcome measures, are considered to have insufficient quality and contradictory results. Convincing evidence is available only for postoperative nausea, for which acupuncture appears to be of benefit, and smoking cessation, where acupuncture is no more effective than sham acupuncture.

Conclusions

A large number of systematic reviews on acupuncture exists. What is most obvious from these reviews is the need for (the funding of) well-designed, larger clinical trials.

Background

Complementary therapies are widely used throughout the world [1,2,3] but their effectiveness is controversial. Although these therapies are clearly under-researched compared to their relevance in actual care, the total number of clinical trials in many areas is considerable [4]. There is a need to know what evidence is available and which questions have not yet been addressed. Systematic reviews are considered to be the best available method to this end [5]. In recent years an increasing number of such reviews has been performed in a variety of complementary therapies. The objective of our series of reports is to provide a comprehensive collection and transparent summary of the available systematic reviews of clinical trials in three major complementary therapies (acupuncture, herbal medicine, and homeopathy). It was not our primary objective to assess efficacy as we do not consider a review of reviews of a large number of interventions an appropriate tool for this purpose. However, when summarizing the results of systematic reviews it is unavoidable to cite their conclusions on efficacy. Our results are presented in three consecutive articles. This first article deals with acupuncture.

Acupuncture is a therapy that involves the stimulation of defined points on the skin typically by inserting needles; however, related techniques such as manual (acupressure), electrical or laser stimulation of acupuncture points are also often summarised under this term [6,7]. Acupuncture is, together with the use of herbal medicines and other treatment modalities, a part of traditional Chinese medicine. In the West it is often used as a single therapy. The basic idea underlying acupuncture is that disorders related to the flow of Chi (the traditional Chinese concept translated as vital force or energy) can be prevented or treated by stimulating the relevant points on the body surface.

Methods

To be included in this overview reviews had to meet the following criteria: 1) Report reviews prospective (not necessarily controlled) clinical trials of acupuncture or related methods (such as acupressure) in humans. 2) Reports explicitly describe, at least, one of the following issues: a) methods for searching primary studies and eligibility criteria for primary studies; b) methods to assess quality aspects; c) methods to summarise the results of the primary studies. 3) Reports are published in journals, books, theses, or the internet. Reviews published before 1989 and as abstracts only were not included. 4) The primary focus of the report is on treatment effects (not diagnosis, side effects, risks, etc.). There were no language restrictions. Disease-oriented reviews including a variety of interventions were included only if they reviewed at least 4 acupuncture trials.

The primary source for identification of systematic reviews was the register of the Cochrane Complementary Medicine Field. For the compilation of this register a variety of databases including Medline, Embase, CISCOM, AMED and other sources have been searched. In addition, we searched 1) Medline 1989 to July 2000 using a standard strategy to identify systematic reviews [8] (see strategy list) combined with the terms acupuncture or acupressure; and 2) the Cochrane Library (last check in issue 2000, 3). Bibliographies of articles obtained and relevant textbooks were screened for further potentially relevant articles. The literature list from the Complementary Medicine Field register was screened in a first step independently by two reviewers who excluded all references for which they were sure that the papers were not systematic reviews. Abstracts of the publications identified by other means were screened by one reviewer. Full copies were obtained for all potentially relevant papers. One (in 46% of papers), two (53%) or three (1%) reviewers checked eligibility and extracted information (bibliographic details, topic, intervention, inclusion criteria, methodological issues, studies and number of patients included, results, and conclusions) from included reviews using pretested forms. For this report the included reviews were summarised in a tabular format giving basic information on the conditions, interventions, comparisons, number of studies reviewed, methodological features, results, and conclusions drawn by the reviewers (if possible in the original wording). We assessed the following methodological features: Comprehensiveness of the literature search (scored if in addition to Medline other databases and non-electronic sources were searched), whether inclusion and exclusion criteria were explicitly listed, whether the quality of primary studies was assessed using fomal methods (such as scores or checklists), whether a summary of results was provided for each included study, and whether a quantitative meta-analysis was performed.

If several review publications by the same team of reviewers with the same focus and published within a time span of 3 years were available these were considered as updates unless inclusion criteria for the two versions were clearly different.

Strategy to search systematic reviews in the Medline database(Ovid Version)[8]

#1 systematic adj reviews.tw.

#2 data adj synthesis.tw.

#3 published adj studies.ab.

#4 data adj extraction.ab.

#5 meta-analysis/

#6 meta analysis.ti.

#7 comment.pt

#8 letter.pt.

#9 editorial.pt.

#10 animal/

#11 human

#12 10 not (10 and 11)

#13 search terms for specific therapy

#14 13 not (7 or 8 or 9 or 12)

#15 or/1-6

#16 14 and 15

Results

From a total of 48 potentially relevant reviews preselected through the screening process, 39 (published in 45 papers) met the inclusion criteria [953]. Five reviews were excluded as they were not truly systematic reviews (not meeting inclusion criterion 2) [5458] and 4 as they did not focus on treatment effects but on methodological issues [5962].

As expected, many reviews addressed pain (see table 1). Three reviews (published 1989 [10,12], 1990 [11] and 2000 [9]) focused on chronic pain. The study samples (total number of trials covered in any of the reviews 72) and review methods differed considerably among the reviews but all agreed that the available evidence is inconclusive. Back and neck pain were addressed in six reviews (total number of trials covered for each back and neck pain 11). Conclusions regarding back pain were contradictory [13, 1519] while the evidence regarding neck pain was considered inconclusive [13,14]. Six reviews addressed various types of headaches (total number of trials covered 25). The largest review which focused on migraine and tension-type headache [21] drew tentatively positive conclusions. The remaining reviews included fewer studies and the evidence was considered inconclusive [20,[2225]].
Table 1

Systematic reviews of clinical trials of acupuncture & acupressure in pain

Author Year

Indication

Controls

Studies

features

Results

Conclusion

    

1 / 2 / 3

  
    

/ 4 / 5

  

Chronic

      

pain

      

Ezzo 2000

chronic

sham,

51 RCT

y / y / y /

Positive results in 21 studies, negative in 3,

Limited evidence that acupuncture is

[9]

pain

placebo, no

 

y / n

and neutral in 27. Better studies more often

more effective than no treatment,

  

treatment,

  

negative or neutral

inconclusive evidence regarding

  

standard

   

placebo, sham and standard care

ter Riet

chronic

sham,

51 CCT

y / y / y /

Trials small and of low quality. 24 with

The efficacy of acupuncture in the

90/89

pain

other, no

 

y / n

positive and 27 with negative results. Better

treatment of chronic pain remains

[10,11]

 

treatment

  

studies more often negative

doubtful

Patel 89 [12]

chronic

sham, no

14 RCT

n / y / n

Overall patients receiving acupuncture were

Available evidence positive but

 

pain

treatment,

 

/ y / y

18% (p < 0.01) more likely to experience

definitive conclusions difficult due to

  

standard

  

improvement

various potential sources of bias

Smith 2000

back &

sham,

13 RCT

y / y / y /

5 studies positive, 8 studies negative; better

No convincing evidence for the

[13]

neck pain

other, no

 

y / n

studies reported more often negative results

analgetic efficacy of acupuncture for

  

treatment

   

back and neck pain

White 99

neck pain

sham,

14 RCT

y / y / y /

7 studies positive, 7 negative. Of the 8 better

No convincing evidence for the

[14]

 

other, no

 

y / n

studies 5 negative, 3 positive

effectiveness of acupuncture for neck

  

treatment

   

pain

van Tulder

low back

sham,

11 RCT

y / y / y /

Conclusions of primary authors positive in 8

Authors would not recommend acu-

99 [15,16]

pain

other, no

 

y / n

studies, by reviewers for 2 studies.

puncture as regular treatment for low

  

treatment

  

Methodological quality judged as low

back pain. High quality trials needed

Ernst 98 [17]

back pain

sham,

12 RCT

y / y / y /

OR for improvement compared with all

Acupuncture superior to various

  

other, no

 

y / y

control interventions 2.30 (95%CI 1.28–4.13),

control interventions although

  

treatment

  

with sham 1.37 (0.84–2.25). Majority of

insufficient evidence whether

     

studies good quality

superior to sham

Longworth

sciatica

unclear

1 RCT, 6

p / p / n

Most studies of poor quality; a large number

There may be a role for acupuncture

97 [18]

  

CCT, 31

/ y / n

of patients seem to have benefited

treatment of lumbar disk protrusions

   

uncontrolled

  

and sciatica

   

studies

   

ter Riet 89

neck and

unclear

16 RCT, 6

y / p / y

Study design was generally poor. Results

Due to the low methodological quality

[19]

back pain

 

CCT

/ n / n

only discussed for a few better quality

no definitive conclusions can be

     

studies

drawn

Headache

      

McCrory

tension-

sham,

6 RCT

y / y / y /

3 of 4 sham-controlled trials positive (best

Insufficient evidence to draw

2000* [20]

type

physio-

 

y / n

negative), physiotherapy better in 1 of 2 trials

conclusions on the efficacy. Further

 

headache

therapy

   

rigorous trials needed

Melchart 99

idiopathic

sham,

22 RCT

y / y / y /

Majority of 14 sham controlled trials with at

Existing evidence suggests that

[21]

headaches

other, no

 

y / y

least a trend in favour of acupuncture. Trials

acupuncture has a role in headache

  

treatment

  

vs. other treatments contradictory

treatment. However, quality and

      

amount of evidence not fully

      

convincing

Goslin 99

migraine

sham,

6 RCT

y / y / y /

2 of 3 placebo-controlled trials positive,

Insufficient data on acupuncture to

[22]

 

other, no

 

y / n

similar effects as drug treatment in 2 trials

draw conclusions on its efficacy

  

treatment

    

Vernon 99**

tension-

sham,

8 RCT

y / y / y /

2 of 4 sham-controlled trials positive, results

Too few trials and contradictory

[23]

type and

other, no

 

y / n

vs. physiotherapy contradictory

findings precluding definitive

 

cervicogeni

treatment

   

conclusions

 

c

     

ter Riet 89

tension

sham, other

7 RCT, 1

y / p / y

Small study size and methodological

No definitive conclusions on the

[24]

type

treatment

CCT

/ n / n

problems make the available trials

effectiveness of acupuncture for

 

headache

   

uninterpretable

headache can be drawn

ter Riet 89

facial pain

sham

2 RCT

y / p / y

Methodological quality poor

No definitive conclusions possible

[25]

   

/ y / n

  

Pain

      

various

      

Ernst 98 [26]

acute

sham,

11 RCT, 5

y / p / y

The majority of trials imply that acupuncture

Acupuncture can alleviate dental pain

 

dental pain

other, no

CCT

/ y / n

is effective in dental analgesia

but additional research necessary

  

treatment

    

Ernst 99 [27]

temporoma

other and

3 RCT

y / y / n

3 comparisons with standard treatments and

Available data suggest beneficial

 

n-dibular

no

 

/ y / n

2 with no treatment with favorable effects of

effects; more rigorous, sham-

 

joint

treatment

  

acupuncture

controlled trials needed

 

dysfunction

     

*Disease focused review on a variety of interventions including acupunture and acupressure; **Disease focused review on a variety of complementary medicine interventions including acupunture and acupressure Features: 1 = comprehensive search, 2 = explicit inclusion criteria, 3 = formal quality assessment, 4 = summary of results for each included study, 5 = meta-analysis; y = yes, p = partly, n = no, - = not applicable, ? = unclear RCT = randomized controlled trials, CCT = non-randomized controlled trials, CS = cohort studies; OR = odds ratio, RR = rate ratio

The available trials suggest that acupuncture is effective in postoperative pain after dental treatment and temporomandibular dysfunction although further research is still considered necessary [26,27,53].

Systematic reviews of acupuncture and acupressure for rheumatic diseases, addiction, nausea and asthma are summarized in table 2. A variety of rheumatic conditions has been addressed in five reviews. The limited evidence available so far suggests that acupuncture may have favorable effects in fibromyalgia [28]. The majority of the available trials on osteoarthritis report improvement with both sham and true acupuncture but no significant differences between the two [29]. For a variety of other rheumatoid diseases the evidence was considered inconclusive [30,31,32].
Table 2

Systematic reviews of clinical trials of acupuncture & acupressure in rheumatic diseases, addiction, nausea and asthma

    

Feature

  

Author Year

Indication

Controls

Studies

s

Results

Conclusion

    

1 / 2 / 3

  
    

/ 4 / 5

  

Rheumatic diseases

      

Berman 99

fibromylgia

sham, other

3 RCT, 3 CS

y / y / y /

Acupuncture more effective than sham for

Limited amount of evidence positive.

[28]

 

treatments

 

y / n

symptoms and global ratings

Further research needed

Ernst 97 [29]

osteoarthriti

sham, other

13 RCT

y / p / n

Both sham and true acupuncture improve

The notion that acupuncture is

 

s

and no

 

/ y / n

symptoms but better trials suggest no

superior to sham-needling is not

  

treatment

  

difference between the two

supported by data from controlled

      

clinical trials

Lauten-

inflammator

sham, no

2 RCT, 7

n / p / n

Controlled trials contradictory, quality often

Acupuncture cannot be

schläger 97

y

treatment,

CCT, 9 CS

/ y / n

low

recommended for rheumatoid

[30]

rheumatoid

other acup.

   

arthritis, spondarthropathy, lupus

 

diseases

    

eryth., sclerodermia

Jacobs 91**

rheumatic

sham, other

23 CCT

p / y / n

7 trials positive, 13 trials no effect over

No specific conclusion on

[31]

diseases

treatment

 

/ y / n

placebo or control, 3 trials unclear

acupuncture (generally: no

      

convincing evidence for alternative

      

therapies in rheumat.)

ter Riet 89

rheumatoid

sham

1 RCT,

y / p / y

Only 1 trial summarized; this found positive

No definitive conclusions possible

[32]

arthritis

 

2CCT

/ n / n

effects on pain but not on inflammation

 

Addiction

      

White

smoking

sham, other

20 RCT

y / y / y /

Acupuncture vs. sham: OR for cessation

There is no evidence for the specific

2000/99

cessation

and no

 

y / y

1.22 (95%CI 0.99–1.49) after treatment and

effectiveness of acupuncture in

[33,34]

 

treatment

  

1.02 (0.72–1.43) at 12 months. No difference

smoking cessation greater than a

     

compared to other interventions, better than

placebo effect

     

no treatment

 

White 97

smoking

sham

7 RCT

y / y / y /

6 of the 7 studies do not yield cessation rates

Acupuncture for smoking cessation

[35]

cessation

  

y / n

that are significantly different from sham

does not produce an effect greater

     

acupuncture

than placebo

Law 95* [36]

smoking

sham, other

8 RCT

p / p / n

Compared to control 3% (95%CI -1 to 6%)

Acupuncture is ineffective

 

cessation

and no

 

/ n / y

more participants stopped smoking with

 
  

treatment

  

acupuncture

 

ter Riet

A. smoking

sham, other

A. 13 RCT, 2

y / p / y

A. 3 of 15 studies positive

Claims that acupuncture is effective

90/89 [37,38

cessat.

and no

CCT

/ y / n

 

for the treatment of tobacco, alcohol

39]

B. alcohol

treatment,

B. 1RCT, 1

 

B. 2 of 2 studies positive

and heroine addiction are not

 

addict.

other acu

CCT

  

supported by sound clinical research

 

C. heroine

 

C. 5 CCT

 

C. 3 of 5 studies positive

 
 

addict.

     

Nausea

      

Lee 99 [40]

postoperati

sham, other

19 RCT

y / p / y

RR of early vomiting compared to

Acupuncture equivalent to commonly

 

ve nausea

and no

 

/ y / y

antiemetics 0.89 (95%CI 0.47–1.67) and to

used antiemetic drugs. More effective

 

(prevention)

treatment

  

placebo 0.47 (0.34–0.64), late vomiting 0.81

than placebo in first 6 h after surgery

     

(0.46–1.42)

in adults but no benefit observed in

      

children

Aikins

nausea in

sham, no

7 RCT

y / p / n

6 of 7 P6 acupressure trials positive, 1 trial

Available evidence positive but

Murphy 99**

pregnancy

treatment

 

/ y / no

on P6 electrical stimulation positive

equivocal

[41]

      

Jewell 98*

nausea in

sham, no

4 RCT

y / y / y /

3 of 4 P6 acupressure trials positive, 2 cross-

Available evidence positive but

[42]

early

treatment

 

y / y

over trials excluded, best trial negative

equivocal

 

pregnancy

     

Vickers 96

nausea in

sham, other

33 CCT

y / y / y /

27 of 33 trials positive, 11 of 12 sham-

Except when administered under

[43]

surgery,

and no

 

y / n

controlled randomized trials positive

anesthesia P6 acupuncture point

(stimulation

pregnancy,

treatment

   

stimulation seems to be an effective

at point P6)

chemother.

    

antiemetic technic

Asthma

      

Linde 98 [44]

asthma

sham

7 RCT

y / y / y /

Highly heterogeneous trials; two positive, five

It is not yet possible to make any

 

(acute

  

y / p

found no difference

recommendations about the practice

 

attack trials

    

of acupuncture in the treatment of

 

excl.)

    

asthma

Linde 96 [45]

asthma

sham, no,

15 RCT

y / y / y /

Contradictory results, highly heterogeneous

There is insufficient data to draw

  

other

 

y / n

trials

reliable conclusions about the

  

treatment

   

effectiveness of acupuncture for

      

asthma

Kleijnen 91

asthma

unclear

9 RCT, 4

y / p / y

Quality low, contradictory results

Claims that acupuncture is effective

[46] & ter

  

CCT

/ n / n

 

in the treatment of asthma are not

Riet 89 [47]

     

based on well performed clinical trials

legend see table 1

The trials on smoking cessation show in a fairly consistent manner that acupuncture does not seem to have lasting effects over sham acupuncture [3339] (total number of trials covered 22). The only identified review on alcohol and heroin addiction which met our inclusion criteria was published in 1989 [39]; several narrative reviews including new trials on the topic are available (for example [55]).

Trials on nausea are unique in acupuncture research as they focus almost completely on acupuncture or acupressure at a single point (P6). There is good evidence that both acupuncture and acupressure are effective in postoperative nausea (total number of trials covered 24) while the results are equivocal for early morning sickness [4043] (total number of trials covered 8). Most of the trials report positive results but a recent high quality trial could not replicate the findings [63]. Several studies suggest that stimulation of P6 is also effective in treating chemotherapy-induced nausea [43].

Results on asthma are contradictory and all available trials are very small [4447] (total number of trials covered 15).

Systematic reviews of acupuncture and acupressure for a variety of additional conditions are summarized in table 3. While the findings of the available trials on tinnitus and weight reduction do not suggest important effects [48,49,50] a review on acupuncture as an adjunct treatment in stroke rehabilitation found promising results [51].
Table 3

Systematic reviews of clinical trials of acupuncture & acupressure in various conditions

    

Feature

  

Author Year

Indication

Controls

Studies

s

Results

Conclusion

    

1 / 2 / 3

  
    

/ 4 / 5

  

Park 2000

tinnitus

sham, other

6 RCT

y / y / y /

2 unblinded studies positive whereas 4

No evidence from rigorous RCT that

[48]

 

treatment

 

y / n

blinded studies showed no significant effects

acupuncture has specific effects in

     

of acupunct.

the treatment of tinnitus

Dobie 99 *

tinnitus

sham, other

6 RCT

p / p / p

No significant effects shown. Patients in

No specific conclusions for

[49]

 

treatment

 

/ p / n

cross-over studies tend to prefer

acupuncture drawn (generally: no

     

acupuncture

treatment well established)

Ernst 97 [50]

weight or

sham

4 RCT

? / y / y

Two studies positive effect mainly on

Claims that acupuncture reduces

 

appetite

  

/ y / y

appetite, two studies (better quality) negative

weight or appetite not based on well-

 

reduction

    

performed clinical trials

Ernst 96 [51]

stroke

no

5 RCT, 1

y / y / n

All trials suggest positive effects on

Evidence encouraging but not

 

rehabilitatio

treatment

CCT

/ y / n

functional recovery; numerous

compelling

 

n

(routine

  

methodological problems

 
  

only)

    

Harris 97

various

sham,

23 clinical

p / n / y

P6 acupressure effective for nausea, other

No clear conclusion beyond results

(only acu-

 

other, no

studies

/ n / n

research scarce and low quality

drawn

pressure)

 

treatment

    

[52]

      

Rosted 98

dentistry

sham,

15 RCT

y / p / y

Most studies with relevant methodological

The value of acupuncture as an

[53]

(mainly

other, no

 

/ n / n

problems. 11 of 15 trials with positive results

analgesic must be questioned due to

 

temporoma

treatment

   

problems in the trials. But the effect

 

ndibular

    

in temporomandibular dysfunction

 

dysfunction

    

and facial pain seems real

 

)

     

legend see table 1

Finally, there is one review summarizing research on acupressure for various conditions (acceptable evidence only available for nausea [52]) and another on acupuncture in various conditions related to dentistry (reporting promising evidence for temporomandibular dysfunction [53]).

Discussion

Although a considerable number of clinical trials on acupuncture is available the evidence so far is very often inconclusive. Apart from postoperative nausea (positive) and smoking cessation (negative) the reviewers apparently felt unable to make clear conclusions whether acupuncture was effective or not. This finding is somewhat frustrating. The primary problem in acupuncture studies seems to be sample size (most studies are very small). For example, median sample sizes of trials in low back pain, headache and osteoarthirits were 50 [16], 37 [21] and 31 [29], respectively. A second relevant problem is methodological quality. There was an almost uniform call for large, well-designed studies. Why are so few such studies available?

One reason is probably the lack of funding for such studies. There is little industrial interest in acupuncture, so major funding has to come mainly from public resources. In several countries a limited number of larger studies (on low back pain [64] with planned 170 patients and on headache [65] with 300 patients in the UK funded by the NHS; and on osteoarthritis [personal communication, Brian Berman] with 570 patients in the US funded by the NIH) is now underway which might bring some advances. A second - partly related - reason is that a competent research infrastructure has been developed only very slowly. A third reason is that clinical research in acupuncture is difficult. Acupuncture (as other non-drug therapies like physiotherapy) is a term for describing a group of quite heterogeneous interventions. Some providers clearly find it misleading to include techniques without needling into systematic reviews of acupuncture while those who apply acupressure or laser acupuncture often hold the opinion that the crucial issue is the stimulation of the correct point no matter by which way. Acupuncture strategies for the treatment of a specific condition can be highly variable. Some acupuncturists use similar approaches in all patients with a given Western diagnosis while others consider this as inadequate and claim that the treatment has to be "individualized." This is often misunderstood: Patients with the same Western diagnosis get different treatment because they have different diagnoses according to traditional Chinese medicine which uses different disease groups. Furthermore, different schools of acupuncture exist within Western and more traditional approaches.

Another significant problem in acupuncture research is choosing appropriate placebo controls if the objective is to evaluate specific effects. Techniques applied include mock transcutaneous nerve stimulation, sham laser acupuncture, needling superficially, needling wrong or inadequate points etc. There is some evidence that different types of acupuncture "placebos" have different effects [59]. For example, techniques that involve needling (and which are less likely to be distinguishable and therefore are considered as better for blinding) can cause relevant physiological responses [66].

Several reviews described a negative correlation between study quality and outcome (better studies were more often negative; for example [9,11,13]). This finding has to be interpreted with caution. Many reviews included trials with very different control groups: waiting list or no treatment, the various "placebo" techniques listed above, and a variety of active controls. If acupuncture has at least some placebo effect, attributable to the psychological effects of being administered a novel therapy, one would expect placebo-controlled trials to show smaller differences between groups than trials without placebo control. Acupuncture trials without placebo control cannot be blinded and therefore typically score lower on quality scales. Given that links between study quality and outcome are confounded by the issues of non-specific effects, and given that trials with different control groups answer different questions, analyses checking the influence of quality aspects on outcomes should only be performed within groups of trials with comparable controls.

This annotated bibliography of systematic reviews should also be interpreted with great caution. The risk of oversimplification in a systematic review is great. In a review of reviews it is extreme. We summarise the conclusion of a systematic review in a single phrase. Clinical decisions for treatment of individual patients should not be based on our work. For this, patients and health care professionals have to turn to the original reviews. Our aim was to provide a clear summary of what is available and where further information can be found. We tried to be as comprehensive as possible in our search but cannot exclude that we have overlooked eligible work, particularly if this was not published in a journal.

Our findings are generally in accordance with those of a panel of the National Institutes of Health reporting on acupuncture in 1998 [67]. However, the conclusions of the panel that the evidence on acupuncture is promising for a variety of conditions but not conclusive seems slightly more optimistic than the picture which emerges from the available systematic reviews.

We did not systematically search the literature on systematic reviews of side effects of acupuncture. We came across one such review which had collected case reports [68]. However, for a reliable assessment of safety large scale prospective studies or effective surveillance systems are needed in addition.

In conclusion, while in some areas only older reviews are available and some minor topics are not reviewed at all it is obvious that what is needed is new primary research and not new systematic reviews. Future trials should have larger sample sizes, rigorous methods, and should reflect principles and practice of acupuncture as applied in actual practice. Until conclusive data becomes available we must be aware that most decisions in health care regarding acupuncture are based - as in many other areas of medicine - on partial evidence about which reasonable people can disagree.

Declarations

Acknowledgements

KL's work was partly funded by the NIAMS grant 5 U24-AR-43346 -02 and by the Carl and Veronica Carstens Foundation, Essen, Germany.

Authors’ Affiliations

(1)
Centre for Complementary Medicine Research, Department of Internal Medicine II, Technische Universität
(2)
Institute for Social Medicine & Epidemiology, Charité Hospital, Humboldt University
(3)
Memorial Sloan-Kettering Cancer Center
(4)
Consortial Center for Chiropractic Research
(5)
NHS Centre for Reviews & Dissemination, University of York
(6)
Department of Epidemiology, Maastricht University
(7)
Division of Complementary Medicine, Department of Family Medicine, University of Maryland School of Medicine

References

  1. Eisenberg DM, Davis RB, Ettner SL: Trends in alternative medicine use in the United States, 1990-1997. Results of a follow-up national survey. JAMA. 1998, 280: 1569-1575. 10.1001/jama.280.18.1569.View ArticlePubMed
  2. MacLennan AH, Wilson DH, Taylor AW: Prevalence and cost of alternative medicine in Australia. Lancet. 1996, 347: 569-573.View ArticlePubMed
  3. Harris P, Rees R: The prevalence of complementary and alternative medicine use among the general population: a systematic review of the literature. Complement Ther Med. 2000, 8: 88-96. 10.1054/ctim.2000.0353.View ArticlePubMed
  4. Vickers AJ: Bibliometric analysis of randomised trials in complementary medicine. Complement Ther Med. 1997, 6: 185-189.View Article
  5. Cook DJ, Mulrow CD, Haynes RB: Systematic reviews: synthesis of best evidence for clinical decisions. Ann Intern Med. 1997, 126: 376-380.View ArticlePubMed
  6. Zollman C, Vickers A: ABC of complementary medicine. London: BMJ Books,. 2000, : 12-15.
  7. Filshie J, White A: Medical acupuncture. Edinburgh: Churchill Livingstone,. 1997
  8. Glanville J, Lefebrve C: Wichtige Quellen für systematische Reviews. Evidence-Based Medicine, German ed. 2000, 4: 100-101.
  9. Ezzo J, Berman B, Hadhazy VA, Jadad AR, Lao L, Singh BB: Is acupuncture effective for the treatment of chronic pain? A systematic review. Pain. 2000, 86: 217-225. 10.1016/S0304-3959(99)00304-8.View ArticlePubMed
  10. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur en chronische pijn. Huisarts en wetenschap. 1989, 32: 230-238.
  11. ter Riet G, Kleijnen J, Knipschild P: Acupuncture and chronic pain: a criteria-based meta analysis. J Clin Epidemiol. 1990, 43: 1191-1199.View ArticlePubMed
  12. Patel MS, Gutzwiller F, Paccaud F, Marazzi A: A meta-analysis of acupuncture for chronic pain. Int J Epidemiol. 1989, 18: 900-906.View ArticlePubMed
  13. Smith LA, Oldman AD, McQuay HJ, Moore RA: Teasing apart quality and validity in systematic reviews: an example from acupuncture trials in chronic neck and back pain. Pain. 2000, 86: 119-132. 10.1016/S0304-3959(00)00234-7.View ArticlePubMed
  14. White AR, Ernst E: A systematic review of randomised controlled trials of acupuncture for neck pain. Rheumatology. 1999, 38: 143-147. 10.1093/rheumatology/38.2.143.View ArticlePubMed
  15. Tulder MWvan, Cherkin DC, Berman B, Lau L, Koes BW: Acupuncture for low back pain (Cochrane Review). In: The Cochrane Library, Issue 1. 2000, . Oxford: Update Software.
  16. Tulder MWvan, Cherkin DC, Berman B, Lau L, Koes BW: The effectiveness of acupuncture in the management of acute and chronic low back pain. A systematic review within the framework of the Cochrane Collaboration Back Review Group. Spine. 1999, 24: 1113-1123. 10.1097/00007632-199906010-00011.View ArticlePubMed
  17. Ernst E, White AR: Acupuncture for back pain. A meta-analysis of randomised controlled trials. Arch Int Med. 1998, 158: 2235-2241. 10.1001/archinte.158.20.2235.View Article
  18. Longworth W, McCarthy PW: A review of research on acupuncture for the treatment of lumbar disk protrusions and associated neurological symptomatology. J Alternat Compl Med. 1997, 3: 55-76.View Article
  19. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur en nekpijn/rugpijn. Huisarts en wetenschap. 1989, 32: 223-227.
  20. McCrory D, Penzien DB, Gray RN, Hasselblad V: Behavioral and physical treatments for tension-type and cervicogenic headache. Prepared for the Foundation for Chiropractic Education and research. Grant No. 99-05-01. 2000, [http://www.fcer.org]
  21. Melchart D, Linde K, Fischer P: Acupuncture for recurrent headaches: a systematic review of randomised controlled trials. Cephalalgia. 1999, 19: 776-86. 10.1046/j.1468-2982.1999.1909779.x.View Article
  22. Goslin RE, Gray RN, McCrory DC, Penzien D, Rains J, Hasselblad V: Behavioral and physical treatments for migraine headache. Technical review 2.2. 1999, [http://www.clinpol.mc.duke.edu]February . Prepared for the Agency for Health Care Policy and Research under Contract No. 290-94-2025.
  23. Vernon H, McDermaid CS, Hagino C: Systematic review of randomised clinical trials of complementary/alternative therapies in the treatment of tension-type and cervicogenic headache. Complement Ther Med. 1999, 7: 142-155.View ArticlePubMed
  24. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur bij migraine en spanningshoofdpijn. Huisarts en wetenschap. 1989, 32: 258-263.
  25. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur en aangezichtspijn. Huisarts en wetenschap. 1989, 32: 264-266.
  26. Ernst E, Pittler MH: The effectiveness of acupuncture in treating acute dental pain: a systematic review. Br Dent J. 1998, 184: 443-447. 10.1038/sj.bdj.4809654.View ArticlePubMed
  27. Ernst E, White AR: Acupuncture as a treatment for temporomandibular joint dysfunction. A systematic review of randomised trials. Arch Otolaryngol Head Neck Surg. 1999, 125: 269-272.View ArticlePubMed
  28. Berman BM, Ezzo J, Hadhazy V, Swyers JP: Is acupuncture effective in the treatment of fibromyalgia?. J Fam Pract. 1999, 48: 213-218.PubMed
  29. Ernst E: Acupuncture as a symptomatic treatment of osteoarthritis. Scand J Rheumatol. 1997, 26: 444-447.View ArticlePubMed
  30. Lautenschläger J: Akupunktur bei der Behandlung entzündlich-rheumatischer Erkrankungen. Z Rheumatol. 1997, 56: 8-20. 10.1007/s003930050016.View ArticlePubMed
  31. Jacobs JWG, Rasker JJ, van Riel PLCM, Gribnau FWJ, van de Putte LBA: Alternatieve behandelingswijzen bij reumatische aandoeningen; een literatuuronderzoek. Ned Tijdschr Geneeskd. 1991, 135: 317-22.PubMed
  32. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur en reumatoide artritis. Huisarts en wetenschap. 1989, 32: 228-9.
  33. White AR, Rampes H: Acupuncture in smoking cessation (Cochrane Review). In: The Cochrane Library, Issue 4. 1998, . Oxford: Update Software.
  34. White AR, Resch KL, Ernst E: A meta-analysis of acupuncture techniques for smoking cessation. Tobacco Control. 1999, 8: 393-397.PubMed CentralView ArticlePubMed
  35. White AR, Resch KL, Ernst E: Smoking cessation with acupuncture? A 'best evidence synthesis'. Forsch Komplementärmed. 1997, 4: 102-105.View Article
  36. Law M, Ling Tang J: An analysis of the effectiveness of interventions intended to help people stop smoking. Arch Intern Med. 1995, 155: 1933-1941. 10.1001/archinte.155.18.1933.View ArticlePubMed
  37. ter Riet G, Kleijnen J, Knipschild P: A meta-analysis of studies into the effect of acupuncture in addiction. Br J Gen Prac. 1990, 40: 379-382.
  38. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur en stoppen met roken. Huisarts en wetenschap. 1989, 32: 299-303.
  39. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur, alcohol en drugs. Huisarts en wetenschap. 1989, 32: 304-307.
  40. Lee A, Done ML: The use of nonpharmacologic techniques to prevent postoperative nausea and vomiting: a meta-analysis. Anesth Analg. 1999, 88: 1362-1369.PubMed
  41. Aikins Murphy P: Alternative therapies for nausea and vomiting of pregnancy. Obstet Gynecol. 1998, 91: 149-155. 10.1016/S0029-7844(97)00582-6.View ArticlePubMed
  42. Jewell D, Young G: Interventions for nausea and vomiting in early pregnancy (Cochrane Review). In: The Cochrane Library. Oxford, Update Software,. 1998, issue 4:
  43. Vickers AJ: Can acupuncture have specific effects on health? A systematic review of acupuncture antiemesis trials. J Roy Soc Med. 1996, 89: 303-311.PubMed CentralPubMed
  44. Linde K, Jobst K, Panton J: Acupuncture for the treatment of asthma bronchiale (Cochrane Review). In: The Cochrane Library, Issue 4. 1998, . Oxford: Update Software.
  45. Linde K, Worku F, Stör W: Randomised clinical trials of acupuncture for asthma - a systematic review. Forsch Komplementärmed. 1996, 3: 148-155.View Article
  46. Kleijnen J, ter Riet G, Knipschild P: Acupuncture and asthma: a review of controlled trials. Thorax. 1991, 46: 799-802.PubMed CentralView ArticlePubMed
  47. ter Riet G, Kleijnen J, Knipschild P: Acupunctuur en astma. Huisarts en wetenschap. 1989, 32: 267-272.
  48. Park J, White AR, Ernst E: Efficacy of acupuncture as a treatment of tinnitus. Arch Otolaryngol Head Neck Surg. 2000, 126: 489-492.View ArticlePubMed
  49. Dobie RA: A review of randomised clinical trials in tinnitus. Laryngoscope. 1999, 109: 1202-1211. 10.1097/00005537-199908000-00004.View ArticlePubMed
  50. Ernst E: Acupuncture/acupressure for weight reduction?. Wien Klin Wochenschr. 1997, 109: 60-62.PubMed
  51. Ernst E, White AR: Acupuncture as an adjuvant therapy in stroke rehabilitation. Wien med Wschr. 1996, 146: 556-558.PubMed
  52. Harris PE: Acupressure: a review of the literature. Complement Ther Med. 1997, 5: 156-161.View Article
  53. Rosted P: The use of acupuncture in dentistry: a review of the scientific validity of published papers. Oral Diseases. 1998, 4: 100-104.View ArticlePubMed
  54. Beck R: Die kontrollierten Effizienzstudien: Ein tabellarischer Überblick. AKU. 1996, 24: 205-207.
  55. Brewington V, Smith M, Lipton D: Acupuncture as a detoxification treatment: An analysis of controlled research. J Subst Abuse Treatment. 1994, 11: 289-307. 10.1016/0740-5472(94)90040-X.View Article
  56. Diehl DL: Acupuncture for gastrointestinal and hepatobiliary disorders. J Alt Complement Med. 1999, 5: 27-45.View Article
  57. Ernst E: Acupressure for nausea: a best evidence analysis. Europ J Phys Med Res. 1996, 6: 26-
  58. Resch KL, Ernst E: Wirksamkeitsnachweise komplementärer Therapien - Literaturanalyse am Beispiel der Akupunktur. Fortschr Med. 1995, 113(5): 41-47.
  59. Araujo MS: Does the choice of placebo determine the results of clinical studies on acupuncture? A meta-analysis of 100 clinical trials. Forsch Komplementärmed. 1998, 5 (suppl 1): 8-11.
  60. Hammerschlag R, Morris MM: Clinical trials comparing acupuncture with biomedical standard care: a criteria-based evaluation of research design and reporting. Complement Ther Med. 1997, 5: 133-140.View Article
  61. Vickers CJ, Smith C: Analysis of the evidence profile of the effectiveness of complementary therapies in asthma: a qualitative survey and systematic review. Complement Ther Med. 1997, 5: 202-209.View Article
  62. Vickers A, Goyal N, Harland R, Rees R: Do certain countries produce only positive results? A systematic review of controlled trials. Controlled Clinical Trials. 1998, 19: 159-166. 10.1016/S0197-2456(97)00150-5.View ArticlePubMed
  63. O'Brien B, Relya MJ, Taerum T: Efficacy of P6 acupressure in the treatment of nausea and vomiting during pregnancy. Am J Obstet Gynecol. 1996, 174: 708-715.View ArticlePubMed
  64. Thomas KJ, Fitter M, Brazier J: Longer-term clinical and economic benefits of offering acupuncture to patients with chronic low back pain assessed as suitable for primary care management. Complement Ther Med. 1999, 7: 91-100.View ArticlePubMed
  65. Vickers A, Rees R, Zollman C, Smith C, Ellis N: Acupuncture for migraine and headache in primary care: a protocol for a pragmatic, randomized trial. Complement Ther Med. 1999, 7: 3-18.View ArticlePubMed
  66. Vincent C, Lewith G: Placebo controls for acupuncture studies. J Roy Soc Med. 1995, 88: 199-202.PubMed CentralPubMed
  67. NIH Consensus Development Panel on Acupuncture: Acupuncture. JAMA. 1998, 280: 1518-1524.View Article
  68. Ernst E, White A: Life-threatening adverse reactions after acupuncture? A systematic review. Pain. 1997, 71: 123-126. 10.1016/S0304-3959(97)03368-X.View ArticlePubMed
  69. Pre-publication history

    1. The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/content/backmatter/1472-6882-1-3-b1.pdf

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