Download Lectures on Biostatistics (1971). Corrected and searchable version of Google books edition
Download review of Lectures on Biostatistics (THES, 1973).
BMJ Group
This piece is almost identical with today’s Spectator Health article.
This week there has been enormously wide coverage in the press for one of the worst papers on acupuncture that I’ve come across. As so often, the paper showed the opposite of what its title and press release, claimed. For another stunning example of this sleight of hand, try Acupuncturists show that acupuncture doesn’t work, but conclude the opposite: journal fails, published in the British Journal of General Practice).
Presumably the wide coverage was a result of the hyped-up press release issued by the journal, BMJ Acupuncture in Medicine. That is not the British Medical Journal of course, but it is, bafflingly, published by the BMJ Press group, and if you subscribe to press releases from the real BMJ. you also get them from Acupuncture in Medicine. The BMJ group should not be mixing up press releases about real medicine with press releases about quackery. There seems to be something about quackery that’s clickbait for the mainstream media.
As so often, the press release was shockingly misleading: It said
Acupuncture may alleviate babies’ excessive crying Needling twice weekly for 2 weeks reduced crying time significantly
This is totally untrue. Here’s why.
|
Luckily the Science Media Centre was on the case quickly: read their assessment. The paper made the most elementary of all statistical mistakes. It failed to make allowance for the jelly bean problem. The paper lists 24 different tests of statistical significance and focusses attention on three that happen to give a P value (just) less than 0.05, and so were declared to be "statistically significant". If you do enough tests, some are bound to come out “statistically significant” by chance. They are false postives, and the conclusions are as meaningless as “green jelly beans cause acne” in the cartoon. This is called P-hacking and it’s a well known cause of problems. It was evidently beyond the wit of the referees to notice this naive mistake. It’s very doubtful whether there is anything happening but random variability. And that’s before you even get to the problem of the weakness of the evidence provided by P values close to 0.05. There’s at least a 30% chance of such values being false positives, even if it were not for the jelly bean problem, and a lot more than 30% if the hypothesis being tested is implausible. I leave it to the reader to assess the plausibility of the hypothesis that a good way to stop a baby crying is to stick needles into the poor baby. If you want to know more about P values try Youtube or here, or here. |
|
One of the people asked for an opinion on the paper was George Lewith, the well-known apologist for all things quackish. He described the work as being a "good sized fastidious well conducted study ….. The outcome is clear". Thus showing an ignorance of statistics that would shame an undergraduate.
On the Today Programme, I was interviewed by the formidable John Humphrys, along with the mandatory member of the flat-earth society whom the BBC seems to feel obliged to invite along for "balance". In this case it was professional acupuncturist, Mike Cummings, who is an associate editor of the journal in which the paper appeared. Perhaps he’d read the Science media centre’s assessment before he came on, because he said, quite rightly, that
"in technical terms the study is negative" "the primary outcome did not turn out to be statistically significant"
to which Humphrys retorted, reasonably enough, “So it doesn’t work”. Cummings’ response to this was a lot of bluster about how unfair it was for NICE to expect a treatment to perform better than placebo. It was fascinating to hear Cummings admit that the press release by his own journal was simply wrong.
Listen to the interview here
Another obvious flaw of the study is that the nature of the control group. It is not stated very clearly but it seems that the baby was left alone with the acupuncturist for 10 minutes. A far better control would have been to have the baby cuddled by its mother, or by a nurse. That’s what was used by Olafsdottir et al (2001) in a study that showed cuddling worked just as well as another form of quackery, chiropractic, to stop babies crying.
Manufactured doubt is a potent weapon of the alternative medicine industry. It’s the same tactic as was used by the tobacco industry. You scrape together a few lousy papers like this one and use them to pretend that there’s a controversy. For years the tobacco industry used this tactic to try to persuade people that cigarettes didn’t give you cancer, and that nicotine wasn’t addictive. The main stream media obligingly invite the representatives of the industry who convey to the reader/listener that there is a controversy, when there isn’t.
Acupuncture is no longer controversial. It just doesn’t work -see Acupuncture is a theatrical placebo: the end of a myth. Try to imagine a pill that had been subjected to well over 3000 trials without anyone producing convincing evidence for a clinically useful effect. It would have been abandoned years ago. But by manufacturing doubt, the acupuncture industry has managed to keep its product in the news. Every paper on the subject ends with the words "more research is needed". No it isn’t.
Acupuncture is pre-scientific idea that was moribund everywhere, even in China, until it was revived by Mao Zedong as part of the appalling Great Proletarian Revolution. Now it is big business in China, and 100 percent of the clinical trials that come from China are positive.
if you believe them, you’ll truly believe anything.
Follow-up
29 January 2017
Soon after the Today programme in which we both appeared, the acupuncturist, Mike Cummings, posted his reaction to the programme. I thought it worth posting the original version in full. Its petulance and abusiveness are quite remarkable.
I thank Cummings for giving publicity to the video of our appearance, and for referring to my Wikipedia page. I leave it to the reader to judge my competence, and his, in the statistics of clinical trials. And it’s odd to be described as a "professional blogger" when the 400+ posts on dcscience.net don’t make a penny -in fact they cost me money. In contrast, he is the salaried medical director of the British Medical Acupuncture Society.
It’s very clear that he has no understanding of the error of the transposed conditional, nor even the mulltiple comparison problem (and neither, it seems, does he know the meaning of the word ‘protagonist’).
I ignored his piece, but several friends complained to the BMJ for allowing such abusive material on their blog site. As a result a few changes were made. The “baying mob” is still there, but the Wikipedia link has gone. I thought that readers might be interested to read the original unexpurgated version. It shows, better than I ever could, the weakness of the arguments of the alternative medicine community. To quote Upton Sinclair:
“It is difficult to get a man to understand something, when his salary depends upon his not understanding it.”
It also shows that the BBC still hasn’t learned the lessons in Steve Jones’ excellent “Review of impartiality and accuracy of the BBC’s coverage of science“. Every time I appear in such a programme, they feel obliged to invite a member of the flat earth society to propagate their make-believe.
Acupuncture for infantile colic – misdirection in the media or over-reaction from a sceptic blogger?26 Jan, 17 | by Dr Mike Cummings So there has been a big response to this paper press released by BMJ on behalf of the journal Acupuncture in Medicine. The response has been influenced by the usual characters – retired professors who are professional bloggers and vocal critics of anything in the realm of complementary medicine. They thrive on oiling up and flexing their EBM muscles for a baying mob of fellow sceptics (see my ‘stereotypical mental image’ here). Their target in this instant is a relatively small trial on acupuncture for infantile colic.[1] Deserving of being press released by virtue of being the largest to date in the field, but by no means because it gave a definitive answer to the question of the efficacy of acupuncture in the condition. We need to wait for an SR where the data from the 4 trials to date can be combined. So what about the research itself? I have already said that the trial was not definitive, but it was not a bad trial. It suffered from under-recruiting, which meant that it was underpowered in terms of the statistical analysis. But it was prospectively registered, had ethical approval and the protocol was published. Primary and secondary outcomes were clearly defined, and the only change from the published protocol was to combine the two acupuncture groups in an attempt to improve the statistical power because of under recruitment. The fact that this decision was made after the trial had begun means that the results would have to be considered speculative. For this reason the editors of Acupuncture in Medicine insisted on alteration of the language in which the conclusions were framed to reflect this level of uncertainty. DC has focussed on multiple statistical testing and p values. These are important considerations, and we could have insisted on more clarity in the paper. P values are a guide and the 0.05 level commonly adopted must be interpreted appropriately in the circumstances. In this paper there are no definitive conclusions, so the p values recorded are there to guide future hypothesis generation and trial design. There were over 50 p values reported in this paper, so by chance alone you must expect some to be below 0.05. If one is to claim statistical significance of an outcome at the 0.05 level, ie a 1:20 likelihood of the event happening by chance alone, you can only perform the test once. If you perform the test twice you must reduce the p value to 0.025 if you want to claim statistical significance of one or other of the tests. So now we must come to the predefined outcomes. They were clearly stated, and the results of these are the only ones relevant to the conclusions of the paper. The primary outcome was the relative reduction in total crying time (TC) at 2 weeks. There were two significance tests at this point for relative TC. For a statistically significant result, the p values would need to be less than or equal to 0.025 – neither was this low, hence my comment on the Radio 4 Today programme that this was technically a negative trial (more correctly ‘not a positive trial’ – it failed to disprove the null hypothesis ie that the samples were drawn from the same population and the acupuncture intervention did not change the population treated). Finally to the secondary outcome – this was the number of infants in each group who continued to fulfil the criteria for colic at the end of each intervention week. There were four tests of significance so we need to divide 0.05 by 4 to maintain the 1:20 chance of a random event ie only draw conclusions regarding statistical significance if any of the tests resulted in a p value at or below 0.0125. Two of the 4 tests were below this figure, so we say that the result is unlikely to have been chance alone in this case. With hindsight it might have been good to include this explanation in the paper itself, but as editors we must constantly balance how much we push authors to adjust their papers, and in this case the editor focussed on reducing the conclusions to being speculative rather than definitive. A significant result in a secondary outcome leads to a speculative conclusion that acupuncture ‘may’ be an effective treatment option… but further research will be needed etc… Now a final word on the 3000 plus acupuncture trials that DC loves to mention. His point is that there is no consistent evidence for acupuncture after over 3000 RCTs, so it clearly doesn’t work. He first quoted this figure in an editorial after discussing the largest, most statistically reliable meta-analysis to date – the Vickers et al IPDM.[2] DC admits that there is a small effect of acupuncture over sham, but follows the standard EBM mantra that it is too small to be clinically meaningful without ever considering the possibility that sham (gentle acupuncture plus context of acupuncture) can have clinically relevant effects when compared with conventional treatments. Perhaps now the best example of this is a network meta-analysis (NMA) using individual patient data (IPD), which clearly demonstrates benefits of sham acupuncture over usual care (a variety of best standard or usual care) in terms of health-related quality of life (HRQoL).[3] |
30 January 2017
I got an email from the BMJ asking me to take part in a BMJ Head-to-Head debate about acupuncture. I did one of these before, in 2007, but it generated more heat than light (the only good thing to come out of it was the joke about leprechauns). So here is my polite refusal.
|
Hello Thanks for the invitation, Perhaps you should read the piece that I wrote after the Today programme Why don’t you do these Head to Heads about genuine controversies? To do them about homeopathy or acupuncture is to fall for the “manufactured doubt” stratagem that was used so effectively by the tobacco industry to promote smoking. It’s the favourite tool of snake oil salesman too, and th BMJ should see that and not fall for their tricks. Such pieces night be good clickbait, but they are bad medicine and bad ethics. All the best David |
Today brings a small setback for those of us interested in spreading sensible ideas about science. According to a press release
“The BMJ Group is to begin publishing a medical journal on acupuncture from next year, it was announced today (Tuesday 11 November 2008).
This will be the first complementary medicine title that the BMJ Group has published.”
And they are proud of that? What one earth is going on? The BMJ group is a publishing company which says, of itself,
“Our brand stands for medical credibility. We are one of the world’s best known and most respected medical publishers.”
Well perhaps it used to be.
They have certainly picked a very bad moment for this venture. In the last year there have been at least five good books that assess the evidence carefully and honestly. Of these, the ones that are perhaps the best on the subject of acupuncture are Singh & Ernst’s Trick or Treatment and Barker Bausell’s Snake Oil Science. Both Ernst and Bausell have first hand experience of acupuncture research. And crucially, none of these authors has any financial interest in whether the judgement goes for acupuncture or against it.
Here are quotations from Singh & Ernst’s conclusions
“Reliable conclusions from systematic reviews make it clear that acupuncture does not work for a whole range of conditions, except as a placebo.”
“There are some high quality trials that support the use of acupuncture for some types of pain and nausea, but there are also high quality trials that contradict this conclusion. In short, the evidence is neither consistent nor convincing – it is borderline.”
The House of Lords’ report in 2000 tended to give acupuncture the benefit of the (very considerable) doubt that existed at the time the report was written. Since that time there have been a lot of very well-designed trials of acupuncture.
Now it is quite clear that, for most (and quite possibly all) conditions, acupuncture is no more than a particularly theatrical placebo. Perhaps that is not surprising insofar as the modern western practice of acupuncture owes more to Chinese nationalistic propaganda that started in the time of Mao-Tse Tung than it owes to ancient wisdom (which often turns out to be bunk anyway).
The BMJ Group has decided to endorse acupuncture at a time when it is emerging that the evidence for any specific effect is very thin indeed. Well done.
The journal in question is this.
Acupuncture in Medicine is a quarterly title, which aims to build the evidence base for acupuncture. It is currently self-published by the British Medical Acupuncture Society (BMAS).
One good thing can be said about the Society and the Journal. That is that they don’t espouse all the mumbo-jumbo about ‘meridians’ and ‘Qi’. This, of course, puts them at odds with the vast majority of acupuncture teaching. This sort of internecine warfare between competing sects is characteristic of all sorts of alternative medicine. But that is just ideology. What matters is whether or not sticking needles in you is actually anything more than a placebo.
British Medical Acupuncture Society (BMAS)
The British Medical Acupuncture Society (BMAS). is “a registered charity established to encourage the use and scientific understanding of acupuncture within medicine for the public benefit.”. The phrase “encourage the use” suggests that they do not even envisage the possibility that it might not work. Their web site includes these claims.
Acupuncture can help in a variety of conditions:
- Pain relief for a wide range of painful conditions
- Nausea, especially postoperative nausea and vomiting
- Overactive bladder, also known as bladder detrusor instability
- Menstrual and menopausal problems, eg period pains and hot flushes
- Allergies such as hay fever and some types of allergic rashes
- Some other skin problems such as ulcers, itching and localised rashes
- Sinus problems and more
Presumably the word “help” is chosen carefully to fall just short of “cure”. The claims are vaguely worded, but let’s see what we can find about them from systematic reviews. It appears that the BMAS is being rather optimistic about the evidence.
BMJ Clinical Evidence is considered reliable and is particular interesting because it is owned by the BMJ Publishing Group.
Low Back Pain (chronic) Acupuncture is listed as being of “unknown effectiveness”.
Dysmenorrhoea Acupuncture is listed as being of “unknown effectiveness”.
Osteoarthritis of the knee. Acupuncture is listed as being of “unknown effectiveness”.
Psoriasis (chronic plaque) Acupuncture is listed as being of “unknown effectiveness”.
Neck pain “Acupuncture may be more effective than some types of sham treatment (not further defined) or inactive treatment (not further defined) at improving pain relief at the end of treatment or in the short term (less than 3 months), but not in the intermediate term (not defined) or in the long term (not defined)”
Headache (chronic tension-type) Acupuncture is listed as being of “unknown effectiveness”.
What about the greatest authority, the Cochrane Reviews?
Cochrane Reviews
Low back pain The data do not allow firm conclusions about the effectiveness of acupuncture for acute low-back pain. For chronic low-back pain, acupuncture is more effective for pain relief and functional improvement than no treatment or sham treatment immediately after treatment and in the short-term only. Acupuncture is not more effective than other conventional and “alternative” treatments. The data suggest that acupuncture and dry-needling may be useful adjuncts to other therapies for chronic low-back pain. Because most of the studies were of lower methodological quality, there certainly is a further need for higher quality trials in this area.
Chronic asthma. There is not enough evidence to make recommendations about the value of acupuncture in asthma treatment. Further research needs to consider the complexities and different types of acupuncture.
But most of the vaguely-worded claims made by BMAS have not been the subject of Cochrane reviews. The obvious interpretation of that is that there is not enough evidence to make it worth writing a review. In which case, why does BMAS claim that acupuncture can “help”?
Bandolier is another excellent source of high quality information, This was their view in September 2006
“Large, high-quality randomised trials of acupuncture have been published since the reviews. In fibromyalgia, chemotherapy-induced nausea and vomiting, breech presentation, tension headache, and migraine, all were negative compared with sham acupuncture. One in osteoarthritis of the knee, had statistical improvement over sham acupuncture at three months, but not later. Both large trials and this review of reviews come to the same general conclusion; that over a whole range of conditions and outcomes acupuncture cannot yet be shown to be effective.”
After thousands of years of acupuncture (or at least almost 40 years in the West) there seems to be very little to show for it.
The journal: Acupuncture in Medicine
What about the journal in question? Like all journals devoted to alternative medicine, it claims to be evidence-based. And like all journals devoted to alternative medicine it suffers from a fatal conflict of interest. If this journal were ever to conclude that acupuncture is a placebo, it would destroy the journal and the livelihoods of many of the people who write for it.
Scanning the first three issues of 2008 shows that it is very much like other alternative medicine journals. Most of the papers don’t address the critical question, is it a placebo. And most papers end up rather limply, with a statement along the lines “acupuncture may be useful for ***. More research is needed.”
The editor in chief of the journal is Dr Adrian White, and its editor is Michael Cummings. White is quoted by Ernst in the Guardian in 2004.
“We need to provide hard evidence to support what we all see in our clinics every day: that the modern approach to acupuncture works, and is highly relevant to the new, patient-centred NHS.” .
That means the answer is assumed in advance. That just isn’t science.. ‘We know the answer, all we have to do now is get some evidence’.
Why should the BMJ Group want to do a thing like this?
The press release says
Commenting on the move, BMJ and BMJ Journals Publishing Director, Peter Ashman, said “The journal is a good complement for our existing portfolio of journals and we’re certain that the Society’s members and other subscribers will appreciate the benefits of the decision the BMAS has made on their behalf.”
He continued: “The BMAS is ambitious for its journal to grow and flourish and we’re looking forward to working with the Society to develop an editorial and commercial strategy which will achieve the aims of BMAS and those of its members, while reaching out to the wider global community interested in this fascinating area of medicine.”
Yes, you got it. Money. The same motive that causes some vice-chancellors to bring their university into disrepute by awarding BSc degrees in subjects that are not only not science, but which are oftenly openly anti-science.
Conscience doesn’t seem to bother these people, so let’s put the problem in purely cash terms.
Both the BMJ Group and the vice-chancellors will have to decide whether the cash they gain is sufficient to counterbalance the corrosive effects of their actions on their own reputations.
Follow-up
Only a couple of days later, two new trials show acupuncture is no different from sham controls for helping IVF pregnancy rates. James Randerson in the Guardian writes thus.
“Acupuncture aimed at improving IVF success rates is widely offered by fertility clinics in the UK. In the first of the studies, researchers in Hong Kong split 370 women receiving IVF into two groups. One group received real acupuncture before and after having an IVF embryo implanted into their uterus. The other had the same procedure, except the treatment used retractable needles that did not penetrate the skin.”
“Of the 185 who received the sham treatment, 91 achieved a clinical pregnancy (foetal heartbeat identified using ultrasound) and 71 had a successful delivery. This compared with 72 clinical pregnancies in the true acupuncture group and 55 live births. The differences between the groups were not statistically significant.”
“In a second study, researchers in Chicago used a similar design in which 124 women received true or sham acupuncture. The control group had their skin punctured by real acupuncture needles, but not at genuine “Qi-lines” on the body. In the true acupuncture group, 43.9% achieved a clinical pregnancy, compared with 55.2% of the women given the sham treatment. “
The original paper for the first study can be seen here.