MD, PhD, FMedSci, FRSB, FRCP, FRCPEd.

Chinese studies

This post has an odd title and addresses an odd subject. I am sure some people reading it will ask themselves “has he finally gone potty; is he a bit xenophobic, chauvinistic, or what?” I can assure you none of the above is the case.

Since many years, I have been asked to peer-review Chinese systematic reviews and meta-analyses of TCM-trials submitted to various journals and to the Cochrane Collaboration for publication, and I estimate that around 300 such articles are available today. Initially, I thought they were a valuable contribution to our knowledge, particularly for the many of us who cannot read Chinese languages. I hoped they might provide reliable information about this huge and potentially important section of the TCM-evidence. After doing this type of work for some time, I became more and more frustrated; now I have decided not to accept this task any longer – not because it is too much trouble, but because I have come to the conclusion that these articles are far less helpful than I had once assumed; in fact, I now fear that they are counter-productive.

In order to better understand what I mean, it might be best to use an example; this recent systematic review seems as good for that purpose as any.

Its Chinese authors “hypothesized that the eligible trials would provide evidence of the effect of Chinese herbs on bone mineral density (BMD) and the therapeutic benefits of Chinese medicine treatment in patients with bone loss. Randomized controlled trials (RCTs) were thus retrieved for a systematic review from Medline and 8 Chinese databases. The authors identified 12 RCTs involving a total of 1816 patients. The studies compared Chinese herbs with placebo or standard anti-osteoporotic therapy. The pooled data from these RCTs showed that the change of BMD in the spine was more pronounced with Chinese herbs compared to the effects noted with placebo. Also, in the femoral neck, Chinese herbs generated significantly higher increments of BMD compared to placebo. Compared to conventional anti-osteoporotic drugs, Chinese herbs generated greater BMD changes.

In their abstract, the part on the paper that most readers access, the authors reached the following conclusions: “Our results demonstrated that Chinese herb significantly increased lumbar spine BMD as compared to the placebo or other standard anti-osteoporotic drugs.” In the article itself, we find this more detailed conclusion: “We conclude that Chinese herbs substantially increased BMD of the lumbar spine compared to placebo or anti-osteoporotic drugs as indicated in the current clinical reports on osteoporosis treatment. Long term of Chinese herbs over 12 months of treatment duration may increase BMD in the hip more effectively. However, further studies are needed to corroborate the positive effect of increasing the duration of Chinese herbs on outcome as the results in this analysis are based on indirect comparisons. To date there are no studies available that compare Chinese herbs, Chinese herbs plus anti-osteoporotic drugs, and anti-osteoporotic drug versus placebo in a factorial design. Consequently, we are unable to draw any conclusions on the possible superiority of Chinese herbs plus anti-osteoporotic drug versus anti-osteoporotic drug or Chinese herb alone in the context of BMD.

Most readers will feel that this evidence is quite impressive and amazingly solid; they might therefore advocate routinely using Chinese herbs for the common and difficult to treat problem of osteoporosis. The integration of TCM might avoid lots of human suffering, prolong the life of many elderly patients, and save us all a lot of money. Why then am I not at all convinced?

The first thing to notice is the fact that we do not really know which of the ~7000 different Chinese herbs should be used. The article tells us surprisingly little about this crucial point. And even, if we manage to study this question in more depth, we are bound to get thoroughly confused; there are simply too many herbal mixtures and patent medicines to easily identify the most promising candidates.

The second and more important hurdle to making sense of these data is the fact that most of the primary studies originate from inaccessible Chinese journals and were published in Chinese languages which, of course, few people in the West can understand. This is entirely our fault, some might argue, but it does mean that we have to believe the authors, take their words at face value, and cannot check the original data. You may think this is fine, after all, the paper has gone through a rigorous peer-review process where it has been thoroughly checked by several top experts in the field. This, however, is a fallacy; like you and me, the peer-reviewers might not read Chinese either! (I don’t, and I reviewed quite a few of these papers; in some instances, I even asked for translations of the originals to do the job properly but this request was understandably turned down) In all likelihood, the above paper and most similar articles have not been properly peer-reviewed at all.

The third and perhaps most crucial point can only be fully appreciated, if we were able to access and understand the primary studies; it relates to the quality of the original RCTs summarised in such systematic reviews. The abstract of the present paper tells us nothing at all about this issue. In the paper, however, we do find a formal assessment of the studies’ risk of bias which shows that the quality of the included RCTs was poor to very poor. We also find a short but revealing sentence: “The reports of all trials mentioned randomization, but only seven described the method of randomization.” This remark is much more significant than it may seem: we have shown that such studies use such terminology in a rather adventurous way; reviewing about 2000 of these allegedly randomised trials, we found that many Chinese authors call a trial “randomised” even in the absence of a control group (one cannot randomise patients and have no control group)! They seem to like the term because it is fashionable and makes publication of their work easier. We thus have good reason to fear that some/many/most of the studies were not RCTs at all.

The fourth issue that needs mentioning is the fact that very close to 100% of all Chinese TCM-trials report positive findings. This means that either TCM is effective for every indication it is tested for (most unlikely, not least because there are many negative non-Chinese trials of TCM), or there is something very fundamentally wrong with Chinese research into TCM. Over the years, I have had several Chinese co-workers in my team and was invariably impressed by their ability to work hard and efficiently; we often discussed the possible reasons for the extraordinary phenomenon of 0% negative Chinese trials. The most plausible answer they offered was this: it would be most impolite for a Chinese researcher to produce findings which contradict the opinion of his/her peers.

In view of these concerns, can we trust the conclusions of such systematic reviews? I don’t think so – and this is why I have problems with research of this nature. If there are good reasons to doubt their conclusions, these reviews might misinform us systematically, they might not further but hinder progress, and they might send us up the garden path. This could well be in the commercial interest of the Chinese multi-billion dollar TCM-industry, but it would certainly not be in the interest of patients and good health care.

This week is acupuncture awareness week, and I will use this occasion to continue focusing on this therapy. This first time ever event is supported by the British Acupuncture Council who state that it aims to “help better inform people about the ancient practice of traditional acupuncture. With 2.3 million acupuncture treatments carried out each year, acupuncture is one of the most popular complementary therapies practised in the UK today.

Right, let’s inform people about acupuncture then! Let’s show them that there is often more to acupuncture research than meets the eye.

My team and I have done lots of research into acupuncture and probably published more papers on this than any other subject. We had prominent acupuncturists on board from the UK, Korea, China and Japan, we ran conferences, published books and are proud to have been innovative and productive in our multidisciplinary research. But here I do not intend to dwell on our own achievements, rather I will highlight several important new papers in this area.

Korean authors just published a meta-analysis to assess the effectiveness of acupuncture as  therapy for gouty arthritis. Ten RCTs involving 852 gouty arthritis patients were included. Six studies of 512 patients reported a significant decrease in uric acid in the treatment group compared with a control group, while two studies of 120 patients reported no such effect. The remaining four studies of 380 patients reported a significant decrease in pain in the treatment group.

The authors conclude “that acupuncture is efficacious as complementary therapy for gouty arthritis patients”.

We should be delighted with such a positive and neat result! Why then do I hesitate and have doubts?

I believe that this paper reveals several important issues in relation to systematic reviews of Chinese acupuncture trials and studies of other TCM interventions. In fact, this is my main reason for discussing the new meta-analysis here. The following three points are crucial, in my view:

1) All the primary studies were from China, and 8 of the 10 were only available in Chinese.

2) All of them had major methodological flaws.

3) It has been shown repeatedly that all acupuncture-trials from China are positive.

Given this situation, the conclusions of any review for which there are only Chinese acupuncture studies might as well be written before the actual research has started. If the authors are pro-acupuncture, as the ones of the present article clearly are, they will conclude that “acupuncture is efficacious“. If the research team has some critical thinkers on board, the same evidence will lead to an entirely different conclusion, such as “due to the lack of rigorous trials, the evidence is less than compelling.

Systematic reviews are supposed to be the best type of evidence we currently have; they are supposed to guide therapeutic decisions. I find it unacceptable that one and the same set of data could be systematically analysed to generate such dramatically different outcomes. This is confusing and counter-productive!

So what is there to do? How can we prevent being misled by such articles? I think that medical journals should refuse to publish systematic reviews which so clearly lack sufficient critical input. I also believe that reviewers of predominantly Chinese studies should provide English translations of these texts so that they can be independently assessed by those who are not able to read Chinese – and for the sake of transparency, journal editors should insist on this point.

And what about the value of acupuncture for gouty arthritis? I think I let the readers draw their own conclusion.

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