systematic review

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If we go on the internet, we find no end of positive claims for TM. The official TM website, for instance, claims that more than 350 peer-reviewed research studies on the TM technique have been published in over 160 scientific journals. These studies were conducted at many US and international universities and research centers, including Harvard Medical School, Stanford Medical School, Yale Medical School, and UCLA Medical School.

This may well be true – but do those studies amount to more than a heap of beans? Let’s find out.

The objective of our Cochrane review was to determine the effectiveness of TM for the primary prevention of cardiovascular disease (CVD). We searched the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (2013, Issue 10); MEDLINE (Ovid) (1946 to week three November 2013); EMBASE Classic and EMBASE (Ovid) (1947 to week 48 2013); ISI Web of Science (1970 to 28 November 2013); and Database of Abstracts of Reviews of Effects (DARE) and Health Technology Assessment Database and Health Economics Evaluations Database (November 2013). We also searched the Allied and complementary Medicine Database (AMED) (inception to January 2014) and IndMed (inception to January 2014). We hand searched trial registers and reference lists of reviews and articles and contacted experts in the field. We applied no language restrictions.

We included randomised controlled trials (RCTs) of at least three months’ duration involving healthy adults or adults at high risk of CVD. Trials examined TM only and the comparison group was no intervention or minimal intervention. We excluded trials that involved multi-factorial interventions. Outcomes of interest were clinical CVD events (cardiovascular mortality, all-cause mortality and non-fatal events) and major CVD risk factors (e.g. blood pressure and blood lipids, occurrence of type 2 diabetes, quality of life, adverse events and costs). Two authors independently selected trials for inclusion, extracted data and assessed the risk of bias.

We identified 4 RCTs with a total of 430 participants for inclusion in this review. The included trials were small, short term (three months) and at risk of bias. In all studies, TM was practised for 15 to 20 minutes twice a day. None of the included studies reported all-cause mortality, cardiovascular mortality or non-fatal endpoints as trials were short term, but one study reported survival rate three years after the trial was completed. In view of the considerable statistical heterogeneity between the results of the studies for the only outcomes reported, systolic blood pressure (I2 = 72%) and diastolic blood pressure (I2 = 66%), we decided not to undertake a meta-analysis. None of the four trials reported blood lipids, occurrence of type 2 diabetes, adverse events, costs or quality of life.

We concluded that there are few trials with limited outcomes examining the effectiveness of TM for the primary prevention of CVD. Due to the limited evidence to date, we could draw no conclusions as to the effectiveness of TM for the primary prevention of CVD. There was considerable heterogeneity between trials and the included studies were small, short term and at overall serious risk of bias. More and larger long-term, high-quality trials are needed.

Even though I am a co-author of this review, I am not entirely sure that the last sentence of our conclusion is totally correct. The TM movement has, in my view, all the characteristics of a cult with all its the dangers that cults entail. This means, I think, we ought to be cautious about TM and sceptical about their research and results. At the risk of provoking harsh criticism, I would even say we should be distrustful of their aims and methods.

- Chronic low back pain (CLBP) is a condition which affects so many people that it represents a huge burden to individual patients’ suffering as well as to society in terms of loss of work time and increased economic cost. The number of therapies that have been claimed to be effective for CLBP can hardly be counted. Two of the most common treatments are spinal manipulation and exercise.

The purpose of this systematic review was to determine the effectiveness of spinal manipulation vs prescribed exercise for patients diagnosed with CLBP. Only RCTs that compared head-to-head spinal manipulation to an exercise group were included in this review.

A search of the current literature was conducted using a keyword process in CINAHL, Cochrane Register of Controlled Trials Database, Medline, and Embase. The searches included studies available up to August 2014. Studies were included based on PICOS criteria 1) individuals with CLBP defined as lasting 12 weeks or longer; 2) spinal manipulation performed by a health care practitioner; 3) prescribed exercise for the treatment of CLBP and monitored by a health care practitioner; 4) measurable clinical outcomes for reducing pain, disability or improving function; 5) randomized controlled trials. The methodological quality of all included articles was determined using the criteria developed and used by the Physiotherapy Evidence Database (PEDro).

Only three RCTs met the inclusion criteria of this systematic review. The outcomes used in these studies included Disability Indexes, Pain Scales and function improvement scales. One RCT found spinal manipulation to be more effective than exercise, and the results of another RCT indicated the reverse. The third RCT found both interventions offering equal effects in the long term.

The author concluded that there is no conclusive evidence that clearly favours spinal manipulation or exercise as more effective in treatment of CLBP. More studies are needed to further explore which intervention is more effective.

Whenever there are uncounted treatments for a given condition, one has to ask oneself whether they are all similarly effective or equally ineffective. The present review does unfortunately not answer this question, but I fear the latter might be more true than the former.

Considering how much money we spend on treating CLBP, it is truly surprising to see that just three RCTs are available comparing two of the most commonly used treatments for this condition. Equally surprising is the fact that we simply cannot tell, on the basis of these data, which of the two therapies is more effective.

What consequences should we draw from this information. Obviously we need more high quality trials. But what should we do in the meantime?

Whenever two treatments are equally effective (or, in this case, perhaps equally ineffective?), we must consider other important criteria such as safety and cost. Regular chiropractic care (chiropractors use spinal manipulation on almost every patient, while osteopaths and physiotherapists employ it less frequently)  is neither cheap nor free of serious adverse effects such as strokes; regular exercise has none of these disadvantages. In view of these undeniable facts, it is hard not to come up with anything other than the following recommendation: until new and compelling evidence becomes available, exercise ought to be preferred over spinal manipulation as a treatment of CLBP – and consequently consulting a chiropractor should not be the first choice for CLBP patients.

Moxibustion is an ancient variation of acupuncture using  moxa made from dried mugwort (Artemisia argyi). It has long played an important role in the traditional heath care systems of China and other Asian countries. More recently, it has become popular also in the West. Practitioners use moxa sticks indirectly to warm acupuncture needles, or burn it close to the patient’s skin. Essentially, moxibustion is a treatment where acupuncture points are stimulated mainly or exclusively by the heat of burning moxa.

Because of moxibustion’s long history of usage and the fact that it is employed in many countries for a very wide range of conditions, some might argue that it has stood the ‘test of time’ and should be considered to be a well-established therapy. More critical thinkers would, however, point out that this is not an argument but a classical fallacy.

My team at Exeter regularly had research fellows from Korea and other Asian countries, and we managed to develop a truly productive cooperation. It enabled us to conduct systematic reviews including the Asian literature – and this is how we got involved in an unusual amount of research into moxibustion which, after all, is a fairly exotic alternative therapy. In 2010, we began a series of systematic reviews of moxibustion.

One of the first such articles included 9 RCTs testing the effectiveness of this treatment for stroke rehabilitation. Three RCTs reported favorable effects of moxibustion plus standard care on motor function versus standard care alone Three randomized clinical trials compared the effects of moxibustion on activities of daily living alone but failed to show favorable effects of moxibustion.

Also in 2010, our systematic review of RCTs of moxibustion as a treatment of ulcerative colitis (UC) concluded that current evidence is insufficient to show that moxibustion is an effective treatment of UC. Most of included trials had high risk of bias. More rigorous studies seem warranted.

Our (2010) systematic review od RCTs of moxibustion as a therapy in cancer care found that the evidence was limited to suggest moxibustion is an effective supportive cancer care in nausea and vomiting. However, all studies had a high risk of bias so effectively there was not enough evidence to draw any conclusion.

Our (2010) systematic review of RCTs of moxibustion for treating hypertension concluded that there was insufficient evidence to suggest that moxibustion is an effective treatment for hypertension.

Our (2010) systematic review of RCTs of moxibustion for constipation concluded as follows: Given that the methodological quality of all RCTs was poor, the results from the present review are insufficient to suggest that moxibustion is an effective treatment for constipation. More rigorous studies are warranted.

Our (2010) systematic review found few RCTs were available that test the effectiveness of moxibustion in the management of pain, and most of the existing trials had a high risk of bias. Therefore, more rigorous studies are required before the effectiveness of moxibustion for the treatment of pain can be determined.

Our (2011) systematic review of 14 RCTs of moxibustion for rheumatic conditions failed to provide conclusive evidence for the effectiveness of moxibustion compared with drug therapy in rheumatic conditions.

The, so far, last article in this series has only just been published. The purpose of this systematic review was to assess the efficacy of moxibustion as a treatment of chemotherapy-induced leukopenia. Twelve databases were searched from their inception through June 2014, without a language restriction. Randomized clinical trials (RCTs) were included, if moxibustion was used as the sole treatment or as a part of a combination therapy with conventional drugs for leukopenia induced by chemotherapy. Cochrane criteria were used to assess the risk of bias.

Six RCTs with a total of 681 patients met our inclusion criteria. All of the included RCTs were associated with a high risk of bias. The trials included patients with various types of cancer receiving ongoing chemotherapy or after chemotherapy. The results of two RCTs suggested the effectiveness of moxibustion combined with chemotherapy vs. chemotherapy alone. In four RCTs, moxibustion was more effective than conventional drug therapy. Six RCTs showed that moxibustion was more effective than various types of control interventions in increasing white blood cell counts.

Our conclusion: there is low level of evidence based on these six trials that demonstrates the superiority of moxibustion over drug therapies in the treatment of chemotherapy-induced leukopenia. However, the number of trials, the total sample size, and the methodological quality are too low to draw firm conclusions. Future RCTs appear to be warranted.

Was all this research for nothing?

I know many people who would think so. However, I disagree. If nothing else, these articles demonstrated several facts quite clearly:

  • There is quite a bit of research even on the most exotic alternative therapy; sometimes one needs to look hard and include languages other than English.
  • Studies from China and other Asian counties very rarely report negative results; this fact casts a dark shadow on the credibility of such data.
  • The poor quality of trials in most areas of alternative medicine is lamentable and must be stimulus for researchers in this field to improve their act.
  • Authors of systematic reviews must resist the temptation to draw positive conclusions based on flawed primary data.
  • Moxibustion is a perfect example for demonstrating that the ‘test of time’ is no substitute for evidence.
  • As for moxibustion, it cannot currently be considered an evidence-based treatment for any condition.

On this blog and elsewhere, I have repeatedly cast doubt on the efficacy of homeopathy – not because I have ‘an axe to grind’, as some seem to believe, but because

  1. the assumptions which underpin homeopathy fly in the face of science,
  2. the clinical evidence fails to show that it works beyond a placebo effect.

But was I correct?

A new systematic review and meta-analysis seems to indicate that I was mistaken. It tested the hypothesis that the outcome of an individualised homeopathic treatment (homeopaths would argue that this is the only true approach to homeopathy) is distinguishable from that with placebos.

The review’s methods, including literature search strategy, data extraction, assessment of risk of bias and statistical analysis, were strictly protocol-based. Judgment in seven assessment domains enabled a trial’s risk of bias to be designated as low, unclear or high. A trial was judged to comprise ‘reliable evidence’ if its risk of bias was low or was unclear in one specified domain. ‘Effect size’ was reported as odds ratio (OR), with arithmetic transformation for continuous data carried out as required; OR > 1 signified an effect favouring homeopathy.

Thirty-two eligible RCTs studied 24 different medical conditions in total. Twelve trials were classed ‘uncertain risk of bias’, three of which displayed relatively minor uncertainty and were designated reliable evidence; 20 trials were classed ‘high risk of bias’. Twenty-two trials had extractable data and were subjected to meta-analysis; OR = 1.53 (95% confidence interval (CI) 1.22 to 1.91). For the three trials with reliable evidence, sensitivity analysis revealed OR = 1.98 (95% CI 1.16 to 3.38).

The authors arrived at the following conclusion: medicines prescribed in individualised homeopathy may have small, specific treatment effects. Findings are consistent with sub-group data available in a previous ‘global’ systematic review. The low or unclear overall quality of the evidence prompts caution in interpreting the findings. New high-quality RCT research is necessary to enable more decisive interpretation.

One does not need to be a prophet to predict that the world of homeopathy will declare this article as the ultimate proof of homeopathy’s efficacy beyond placebo. Already the ‘British Homeopathic Association’ has issued the following press release:

Clinical evidence for homeopathy published

Research into the effectiveness of homeopathy as an individualised treatment has produced results that may surprise many from the worlds of science and medicine. The conclusions are reported cautiously, but the new publication is the first of its type to present evidence that medicines prescribed in individualised homeopathy may have specific effects.

The paper, published in the peer-reviewed journal Systematic Reviews,1 reports a rigorous systematic review and meta-analysis of 32 randomised controlled trials (RCTs) in which homeopathic medicines were prescribed on an individual basis to each participant, depending on their particular symptoms.

The overall quality of the RCT evidence was found to be low or unclear, preventing the researchers from reaching decisive conclusions. Three RCTs were identified as “reliable evidence”.

The study was led by Dr Robert Mathie, research development adviser for the British Homeopathic Association, in partnership with a number of collaborators, including colleagues at the Robertson Centre for Biostatistics, University of Glasgow, who independently verified the statistical methods and findings.

“What we found from the statistics,” says Dr Mathie, “is that the effect of individualised treatment using homeopathic medicines was significantly greater than placebos, and that this effect was retained when we included only the three trials with reliable evidence. This tentatively provides proof of concept that homeopathic medicines have clinical treatment effects.”

Surprised? I was stunned and thus studied the article in much detail (luckily the full text version is available online). Then I entered into an email exchange with the first author who I happen to know personally (to his credit, he responded regularly). In the end, this conversation helped me to better understand the review’s methodology; but it also resulted in me being very much underwhelmed by the reliability of the authors’ conclusion.

Normally I would now explain why. But, in this particular case, I thought it would be interesting and helpful to give others the opportunity to examine the article and come up with their own comments. Subsequently I will add my criticisms.


The regular consumption of fish-oil has a potentially favourable role in inflammation, carcinogenesis inhibition and cancer outcomes. An analysis of the literature aimed to review the evidence for the roles of dietary-fish and fish-oil intake in prostate-cancer (PC) risk, aggressiveness and mortality.

A systematic-review, following PRISMA guidelines was conducted. PubMed, MEDLINE and Embase were searched to explore PC-risk, aggressiveness and mortality associated with dietary-fish and fish-oil intake. 37 studies were selected.

A total of 37-studies with 495,321 participants were analysed. They revealed various relationships regarding PC-risk (n = 31), aggressiveness (n = 8) and mortality (n = 3). Overall, 10 studies considering PC-risk found significant inverse trends with fish and fish-oil intake. One found a dose–response relationship whereas greater intake of long-chain-polyunsaturated fatty acids increased risk of PC when considering crude odds-ratios [OR: 1.36 (95% CI: 0.99–1.86); p = 0.014]. Three studies addressing aggressiveness identified significant positive relationships with reduced risk of aggressive cancer when considering the greatest intake of total fish [OR 0.56 (95% CI 0.37–0.86)], dark fish and shellfish-meat (p < 0.0001), EPA (p = 0.03) and DHA (p = 0.04). Three studies investigating fish consumption and PC-mortality identified a significantly reduced risk. Multivariate-OR (95% CI) were 0.9 (0.6–1.7), 0.12 (0.05–0.32) and 0.52 (0.30–0.91) at highest fish intakes.

The authors concluded that fish and fish-oil do not show consistent roles in reducing PC incidence, aggressiveness and mortality. Results suggest that the specific fish type and the fish-oil ratio must be considered. Findings suggest the need for large intervention randomised placebo-controlled trials.

Several other recent reviews have also generated encouraging evidence, e.g.:

Available evidence is suggestive, but currently inadequate, to support the hypothesis that n-3 PUFAs protect against skin malignancy.

…omega-3 fatty acids may exert their anticancer actions by influencing multiple targets implicated in various stages of cancer development, including cell proliferation, cell survival, angiogenesis, inflammation, metastasis and epigenetic abnormalities that are crucial to the onset and progression of cancer.

If I was aiming for a career as a cancer quack, I would now use this evidence to promote my very own cancer prevention and treatment diet. As I have no such ambitions, I should tell you that regular fish oil consumption is no way to treat cancer. It also is no way to prevent cancer. If anything, it might turn out to be a way of slightly reducing the risk of certain cancers. To be sure, we need a lot more research, and once we have it, fish oil will be entirely mainstream. Raising false hopes regarding ‘alternative cancer cures’ based on fairly preliminary evidence is counter-productive, unethical and irresponsible.

Few subjects make chiropractors more uneasy than a discussion of the safety of their spinal manipulations. Many chiropractors flatly deny that there are any risks at all. However, the evidence seems to tell a different story.

The purpose of a new review was to summarise the literature for cases of adverse events in infants and children treated by chiropractors or other manual therapists, identifying treatment type and if a preexisting pathology was present. English language, peer-reviewed journals and non-peer-reviewed case reports discussing adverse events (ranging from minor to serious) were systematically searched from inception of the relevant searchable bibliographic databases through March 2014. Articles not referring to infants or children were excluded.

Thirty-one articles met the selection criteria. A total of 12 articles reporting 15 serious adverse events were found. Three deaths occurred under the care of various providers (1 physical therapist, 1 unknown practitioner, and 1 craniosacral therapist) and 12 serious injuries were reported (7 chiropractors/doctors of chiropractic, 1 medical practitioner, 1 osteopath, 2 physical therapists, and 1 unknown practitioner). High-velocity, extension, and rotational spinal manipulation was reported in most cases, with 1 case involving forcibly applied craniosacral dural tension and another involving use of an adjusting instrument. Underlying preexisting pathology was identified in a majority of the cases.

The authors concluded that published cases of serious adverse events in infants and children receiving chiropractic, osteopathic, physiotherapy, or manual medical therapy are rare. The 3 deaths that have been reported were associated with various manual therapists; however, no deaths associated with chiropractic care were found in the literature to date. Because underlying preexisting pathology was associated in a majority of reported cases, performing a thorough history and examination to exclude anatomical or neurologic anomalies before applying any manual therapy may further reduce adverse events across all manual therapy professions.

This review is a valuable addition to our knowledge about the risks of spinal manipulations. My own review summarised 26 deaths after chiropractic manipulations. In several of these instances, the age of the patient had not been reported. Therefore the above conclusion (no deaths associated with chiropractic) seems a little odd.

The following text is a shortened version of the discussion of my review which, I think, addresses most of the pertinent issues.

 numerous deaths have been associated with chiropractic. Usually high-velocity, short-lever thrusts of the upper spine with rotation are implicated. They are believed to cause vertebral arterial dissection in predisposed individuals which, in turn, can lead to a chain of events including stroke and death. Many chiropractors claim that, because arterial dissection can also occur spontaneously, causality between the chiropractic intervention and arterial dissection is not proven. However, when carefully evaluating the known facts, one does arrive at the conclusion that causality is at least likely. Even if it were merely a remote possibility, the precautionary principle in healthcare would mean that neck manipulations should be considered unsafe until proven otherwise. Moreover, there is no good evidence for assuming that neck manipulation is an effective therapy for any medical condition. Thus, the risk-benefit balance for chiropractic neck manipulation fails to be positive.

Reliable estimates of the frequency of vascular accidents are prevented by the fact that underreporting is known to be substantial. In a survey of UK neurologists, for instance, under-reporting of serious complications was 100%. Those cases which are published often turn out to be incomplete. Of 40 case reports of serious adverse effects associated with spinal manipulation, nine failed to provide any information about the clinical outcome. Incomplete reporting of outcomes might therefore further increase the true number of fatalities.

This review is focussed on deaths after chiropractic, yet neck manipulations are, of course, used by other healthcare professionals as well. The reason for this focus is simple: chiropractors are more frequently associated with serious manipulation-related adverse effects than osteopaths, physiotherapists, doctors or other professionals. Of the 40 cases of serious adverse effects mentioned above, 28 can be traced back to a chiropractor and none to a osteopath. A review of complications after spinal manipulations by any type of healthcare professional included three deaths related to osteopaths, nine to medical practitioners, none to a physiotherapist, one to a naturopath and 17 to chiropractors. This article also summarised a total of 265 vascular accidents of which 142 were linked to chiropractors. Another review of complications after neck manipulations published by 1997 included 177 vascular accidents, 32 of which were fatal. The vast majority of these cases were associated with chiropractic and none with physiotherapy. The most obvious explanation for the dominance of chiropractic is that chiropractors routinely employ high-velocity, short-lever thrusts on the upper spine with a rotational element, while the other healthcare professionals use them much more sparingly.


Guest post by Pete Attkins

Commentator “jm” asked a profound and pertinent question: “What DOES it take for people to get real in this world, practice some common sense, and pay attention to what’s going on with themselves?” This question was asked in the context of asserting that personal experience always trumps the results of large-scale scientific experiments; and asserting that alt-med experts are better able to provide individulized healthcare than 21st Century orthodox medicine.

What does common sense and paying attention lead us to conclude about the following? We test a six-sided die for bias by rolling it 100 times. The number 1 occurs only once and the number 6 occurs many times, never on its own, but in several groups of consecutive sixes.

I think it is reasonable to say that common sense would, and should, lead everyone to conclude that the die is biased and not fit for its purpose as a source of random numbers.

In other words, we have a gut feeling that the die is untrustworthy. Gut instincts and common sense are geared towards maximizing our chances of survival in our complex and unpredictable world — these are innate and learnt behaviours that have enabled humans to survive despite the harshness of our ever changing habitat.

Only very recently in the long history of our species have we developed specialized tools that enable us to better understand our harsh and complex world: science and critical thinking. These tools are difficult to master because they still haven’t been incorporated into our primary and secondary formal education systems.

The vast majority of people do not have these skills therefore, when a scientific finding flies in the face of our gut instincts and/or common sense, it creates an overwhelming desire to reject the finding and classify the scientist(s) as being irrational and lacking basic common sense. It does not create an intense desire to accept the finding then painstakingly learn all of the science that went into producing the finding.

With that in mind, let’s rethink our common sense conclusion that the six-sided die is biased and untrustworthy. What we really mean is that the results have given all of us good reason to be highly suspicious of this die. We aren’t 100% certain that this die is biased, but our gut feeling and common sense are more than adequate to form a reasonable mistrust of it and to avoid using it for anything important to us. Reasons to keep this die rather than discard it might be to provide a source of mild entertainment or to use its bias for the purposes of cheating.

Some readers might be surprised to discover at this point that the results I presented from this apparently heavily-biased die are not only perfectly valid results obtained from a truly random unbiased die, they are to be fully expected. Even if the die had produced 100 sixes in that test, it would not confirm that the die is biased in any way whatsoever. Rolling a truly unbiased die once will produce one of six possible outcomes. Rolling the same die 100 times will produce one unique sequence out of the 6^100 (6.5 x 10^77) possible sequences: all of which are equally valid!

Gut feeling plus common sense rightfully informs us that the probability of a random die producing one hundred consecutive sixes is so incredibly remote that nobody will ever see it occur in reality. This conclusion is also mathematically sound: if there were 6.5 x 10^77 people on Earth, each performing the same test on truly random dice, there is no guarantee that anyone would observe a sequence of one hundred consecutive sixes.

When we observe a sequence such as 2 5 1 4 6 3 1 4 3 6 5 2… common sense informs us that the die is very likely random. If we calculate the arithmetic mean to be very close to 3.5 then common sense will lead us to conclude that the die is both random and unbiased enough to use it as a reliable source of random numbers.

Unfortunately, this is a perfect example of our gut feelings and common sense failing us abysmally. They totally failed to warn us that the 2 5 1 4 6 3 1 4 3 6 5 2… sequence we observed had exactly the same (im)probability of occurring as a sequence of one hundred 6s or any other sequence that one can think of that doesn’t look random to a human observer.

The 100-roll die test is nowhere near powerful enough to properly test a six-sided die, but this test is more than adequately powered to reveal some of our cognitive biases and some of the deficits in our personal mastery of science and critical thinking.

To properly test the die we need to provide solid evidence that it is both truly random and that its measured bias tends towards zero as the number of rolls tends towards infinity. We could use the services of one testing lab to conduct billions of test rolls, but this would not exclude errors caused by such things as miscalibrated equipment and experimenter bias. It is better to subdivide the testing across multiple labs then carefully analyse and appropriately aggregate the results: this dramatically reduces errors caused by equipment and humans.

In medicine, this testing process is performed via systematic reviews of multiple, independent, double-blind, placebo-controlled trials — every trial that is insufficiently powered to add meaningfully to the result is rightfully excluded from the aggregation.

Alt-med relies on a diametrically opposed testing process. It performs a plethora of only underpowered tests; presents those that just happen to show a positive result (just as a random die could’ve produced); and sweeps under the carpet the overwhelming number of tests that produced a negative result. It publishes only the ‘successes’, not its failures. By sweeping its failures under the carpet it feels justified in making the very bold claim: Our plethora of collected evidence shows clearly that it mostly ‘works’ and, when it doesn’t, it causes no harm.

One of the most acidic tests for a hypothesis and its supporting data (which is a mandatory test in a few branches of critical engineering) is to substitute the collected data for random data that has been carefully crafted to emulate the probability mass functions of the collected datasets. This test has to be run multiple times for reasons that I’ve attempted to explain in my random die example. If the proposer of the hypothesis is unable to explain the multiple failures resulting from this acid test then it is highly likely that the proposer either does not fully understand their hypothesis or that their hypothesis is indistinguishable from the null hypothesis.

Aromatherapy is one of the most popular of all alternative therapies. It is most certainly a very agreeable experience. But is it more that a bit of pampering? Does it cure any diseases?

If you believe aromatherapists, their treatment is effective for almost everything. And, of course, there are studies to suggest that, indeed, it works for several conditions. But regular readers of this blog will by now know that it is a bad idea to go by just one single trial; we always must rely on the totality of the most reliable evidence. In other words, we must look for systematic reviews. Recently, such an article has been published.

The aim of this review was to systematically assess the effectiveness of aromatherapy for stress management. Seven databases were searched from their inception through April 2014. RCTs testing aromatherapy against any type of control intervention in healthy but stressed persons assessing stress and cortisol levels were considered. Two reviewers independently performed the selection of the studies, data abstraction and validations. The risk of bias was assessed using Cochrane criteria.

Five RCTs met the authors’ inclusion criteria. Most of the RCTs had high risk of bias. Four RCTs tested the effects of aroma inhalation compared with no treatment, no aroma, and no odour oil. The meta-analysis of these data suggested that aroma inhalation had favourable effects on stress management. Three RCTs tested aroma inhalation on saliva or serum cortisol level compared to controls, and the meta-analysis of these data failed to show significant difference between two groups

The authors concluded that there is limited evidence suggesting that aroma inhalation may be effective in controlling stress. However, the number, size and quality of the RCTs are too low to draw firm conclusions.

This is by no means the only systematic review of this area. In fact, there are so many that, in 2012, we decided to do an overview of systematic reviews evaluating the effectiveness of aromatherapy. We searched 12 electronic databases and our departmental files without restrictions of time or language. The methodological quality of all systematic reviews was evaluated independently by two authors. Of 201 potentially relevant publications, 10 met our inclusion criteria. Most of the systematic reviews were of poor methodological quality. The clinical subject areas were hypertension, depression, anxiety, pain relief, and dementia. For none of the conditions was the evidence convincing. Our conclusion: due to a number of caveats, the evidence is not sufficiently convincing that aromatherapy is an effective therapy for any condition.

So, what does all of this mean? I think it indicates that most of the claims made by aromatherapists are not evidence-based. Or, to express it differently: aromatherapy is hardly more than a bit of old-fashioned pampering – nothing wrong with that, of course, as long as you don’t fall for the hype of those who promote it.

Getting good and experienced lecturers for courses is not easy. Having someone who has done more research than most working in the field and who is internationally known, might therefore be a thrill for students and an image-boosting experience of colleges. In the true Christmas spirit, I am today making the offer of being of assistance to the many struggling educational institutions of alternative medicine .

A few days ago, I tweeted about my willingness to give free lectures to homeopathic colleges (so far without response). Having thought about it a bit, I would now like to extend this offer. I would be happy to give a free lecture to the students of any educational institution of alternative medicine. I suggest to

  • do a general lecture on the clinical evidence of the 4 major types of alternative medicine (acupuncture, chiropractic, herbal medicine, homeopathy) or
  • give a more specific lecture with in-depth analyses of any given alternative therapy.

I imagine that most of the institutions in question might be a bit anxious about such an idea, but there is no need to worry: I guarantee that everything I say will be strictly and transparently evidence-based. I will disclose my sources and am willing to make my presentation available to students so that they can read up the finer details about the evidence later at home. In other words, I will do my very best to only transmit the truth about the subject at hand.

Nobody wants to hire a lecturer without having at least a rough outline of what he will be talking about – fair enough! Here I present a short summary of the lecture as I envisage it:

  • I will start by providing a background about myself, my qualifications and my experience in researching and lecturing on the matter at hand.
  • This will be followed by a background on the therapies in question, their history, current use etc.
  • Next I would elaborate on the main assumptions of the therapies in question and on their biological plausibility.
  • This will be followed by a review of the claims made for the therapies in question.
  • The main section of my lecture would be to review the clinical evidence regarding the efficacy of therapies in question. In doing this, I will not cherry-pick my evidence but rely, whenever possible, on authoritative systematic reviews, preferably those from the Cochrane Collaboration.
  • This, of course, needs to be supplemented by a review of safety issues.
  • If wanted, I could also say a few words about the importance of the placebo effect.
  • I also suggest to discuss some of the most pertinent ethical issues.
  • Finally, I would hope to arrive at a few clear conclusions.

You see, all is entirely up to scratch!

Perhaps you have some doubts about my abilities to lecture? I can assure you, I have done this sort of thing all my life, I have been a professor at three different universities, and I will probably manage a lecture to your students.

A final issue might be the costs involved. As I said, I would charge neither for the preparation (this can take several days depending on the exact topic), nor for the lecture itself. All I would hope for is that you refund my travel (and, if necessary over-night) expenses. And please note: this is  time-limited: approaches will be accepted until 1 January 2015 for lectures any time during 2015.

I can assure you, this is a generous offer  that you ought to consider seriously – unless, of course, you do not want your students to learn the truth!

(In which case, one would need to wonder why not)

The Alexander Technique is a method aimed at re-educating people to do everyday tasks with less muscular and mental tension. According to the ‘Complete Guide to the Alexander Technique’, this method can help you if:

  • You suffer from repetitive strain injury or carpal tunnel syndrome.
  • You have a backache or stiff neck and shoulders.
  • You become uncomfortable when sitting at your computer for long periods of time.
  • You are a singer, musician, actor, dancer or athlete and feel you are not performing at your full potential.

Sounds good!? But which of these claims are actually supported by sound evidence.

Our own systematic review from 2003 of the Alexander Technique (AT) found just 4 clinical studies. Only two of these trials were methodologically sound and clinically relevant. Their results were promising and implied that AT is effective in reducing the disability of patients suffering from Parkinson’s disease and in improving pain behaviour and disability in patients with back pain. A more recent review concluded as follows: Strong evidence exists for the effectiveness of Alexander Technique lessons for chronic back pain and moderate evidence in Parkinson’s-associated disability. Preliminary evidence suggests that Alexander Technique lessons may lead to improvements in balance skills in the elderly, in general chronic pain, posture, respiratory function and stuttering, but there is insufficient evidence to support recommendations in these areas.

This suggests that the ‘Complete Guide’ is based more on wishful thinking than on evidence. But what about the value of AT for performers – after all, it is for this purpose that Alexander developed his method?

A recent systematic review aimed to evaluate the evidence for the effectiveness of AT sessions on musicians’ performance, anxiety, respiratory function and posture. The following electronic databases were searched up to February 2014 for relevant publications: PUBMED, Google Scholar, CINAHL, EMBASE, AMED, PsycINFO and RILM. The search criteria were “Alexander Technique” AND “music*”. References were searched, and experts and societies of AT or musicians’ medicine contacted for further publications.

In total, 237 citations were assessed. 12 studies were included for further analysis, 5 of which were randomised controlled trials (RCTs), 5 controlled but not randomised (CTs), and 2 mixed methods studies. Main outcome measures in RCTs and CTs were music performance, respiratory function, performance anxiety, body use and posture. Music performance was judged by external experts and found to be improved by AT in 1 of 3 RCTs; in 1 RCT comparing neurofeedback (NF) to AT, only NF caused improvements. Respiratory function was investigated in 2 RCTs, but not improved by AT training. Performance anxiety was mostly assessed by questionnaires and decreased by AT in 2 of 2 RCTs and in 2 of 2 CTs.

From this evidence, the authors drew the following conclusion: A variety of outcome measures have been used to investigate the effectiveness of AT sessions in musicians. Evidence from RCTs and CTs suggests that AT sessions may improve performance anxiety in musicians. Effects on music performance, respiratory function and posture yet remain inconclusive. Future trials with well-established study designs are warranted to further and more reliably explore the potential of AT in the interest of musicians.

So, there you are: if you are a performing artist, AT seems to be useful for you. If you have health problems (other than perhaps back pain), I would look elsewhere for help.

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