MD, PhD, FMedSci, FSB, FRCP, FRCPEd

bias

Recently, I have been invited by the final year pharmacy students of the ‘SWISS FEDERAL INSTITUTE OF TECHNOLOGY ZURICH‘ to discuss alternative medicine with them. The aspect I was keen to debate was the issue of retail-pharmacists selling medicines which are unproven or even disproven. Using the example of homeopathic remedies, I asked them how many might, when working as retail-pharmacists, sell such products. About half of them admitted that they would do this. In real life, this figure is probably closer to 100%, and this discrepancy may well be a reflection of the idealism of the students, still largely untouched by the realities of retail-pharmacy.

In our discussions, we also explored the reasons why retail-pharmacists might offer unproven or disproven medicines like homeopathic remedies to their customers. The ethical codes of pharmacists across the world quite clearly prohibit this – but, during the discussions, we all realised that the moral high ground is not easily defended against the necessity of making a living. So, what are the possible motivations for pharmacists to sell bogus medicines?

One reason would be that they are convinced of their efficacy. Whenever I talk to pharmacists, I do not get the impression that many of them believe in homeopathy. During their training, they are taught the facts about homeopathy which clearly do not support the notion of efficacy. If some pharmacists nevertheless were convinced of the efficacy of homeopathy, they would obviously not be well informed and thus find themselves in conflict with their duty to practice according to the current best evidence. On reflection therefore, strong positive belief can probably be discarded as a prominent reason for pharmacists selling bogus medicines like homeopathic remedies.

Another common argument is the notion that, because patients want such products, pharmacists must offer them. When considering it, the tension between the ethical duties as a health care professional and the commercial pressures of a shop-keeper becomes painfully obvious. For a shop-keeper, it may be perfectly fine to offer all products which might customers want. For a heath care professional, however, this is not necessarily true. The ethical codes of pharmacists make it perfectly clear that the sale of unproven or disproven medicines is not ethical. Therefore, this often cited notion may well be what pharmacists feel, but it does not seem to be a valid excuse for selling bogus medicines.

A variation of this theme is the argument that, if patients were unable to buy homeopathic remedies for self-limiting conditions which do not really require treatment at all, they would only obtain more harmful drugs. The notion here is that it might be better to sell harmless homeopathic placebos in order to avoid the side-effects of real but non-indicated medicines. In my view, this argument does not hold water: if no (drug) treatment is indicated, professionals have a duty to explain this to their patients. In this sector of health care, a smaller evil cannot easily be justified by avoiding a bigger one; on the contrary, we should always thrive for the optimal course of action, and if this means reassurance that no medical treatment is needed, so be it.

An all too obvious reason for selling bogus medicines is the undeniable fact that pharmacists earn money by doing so. There clearly is a conflict of interest here, whether pharmacists want to admit it or not – and mostly they fail to do so or play down this motivation in their decision to sell bogus medicines.

Often I hear from pharmacists working in large chain pharmacies like Boots that they have no influence whatsoever over the range of products on sale. This perception mat well be true. But equally true is the fact that no health care professional can be forced to do things which violate their code of ethics. If Boots insists on selling bogus medicines, it is up to individual pharmacists and their professional organisations to change this situation by protesting against such unethical malpractice. In my view, the argument is therefore not convincing and certainly does not provide an excuse in the long-term.

While discussing with the Swiss pharmacy students, I was made aware of yet another reason for selling bogus medicines in pharmacies. Some pharmacists might feel that stocking such products provides an opportunity for talking to patients and informing them about the evidence related to the remedy they were about to buy. This might dissuade them from purchasing it and could persuade them to get something that is effective instead. In this case, the pharmacist would merely offer the bogus medicine in order to advise customers against employing it. This strategy might well be an ethical way out of the dilemma; however, I doubt that this strategy is common practice with many pharmacists today.

With all this, we should keep in mind that there are many shades of grey between the black and white of the two extreme attitudes towards bogus medicines. There is clearly a difference whether pharmacists actively encourage their customers to buy bogus treatments (in the way it often happens in France, for instance), or whether they merely stock such products and, where possible, offer responsible, evidence-based advise to people who are tempted to buy them.

At the end of the lively but fruitful discussion with the Swiss students I felt optimistic: perhaps the days when pharmacists were the snake-oil salesmen of the modern era are counted?

There is much debate about the usefulness of chiropractic. Specifically, many people doubt that their chiropractic spinal manipulations generate more good than harm, particularly for conditions which are not related to the spine. But do chiropractors treat such conditions frequently and, if yes, what techniques do they employ?

This investigation was aimed at describing the clinical practices of chiropractors in Victoria, Australia. It was a cross-sectional survey of 180 chiropractors in active clinical practice in Victoria who had been randomly selected from the list of 1298 chiropractors registered on Chiropractors Registration Board of Victoria. Twenty-four chiropractors were ineligible, 72 agreed to participate, and 52 completed the study.

Each participating chiropractor documented encounters with up to 100 consecutive patients. For each chiropractor-patient encounter, information collected included patient health profile, patient reasons for encounter, problems and diagnoses, and chiropractic care.

Data were collected on 4464 chiropractor-patient encounters between 11 December 2010 and 28 September 2012. In most (71%) cases, patients were aged 25-64 years; 1% of encounters were with infants. Musculoskeletal reasons for the consultation were described by patients at a rate of 60 per 100 encounters, while maintenance and wellness or check-up reasons were described at a rate of 39 per 100 encounters. Back problems were managed at a rate of 62 per 100 encounters.

The most frequent care provided by the chiropractors was spinal manipulative therapy and massage. The table shows the precise conditions treated

Distribution of problems managed (20 most frequent problems), as reported  by chiropractors

Problem group No. (%) of recorded diagnoses* (n = 5985) Rate per 100 encounters (n = 4417) 95% CI ICC
Back problem 2757 (46.07%) 62.42 (55.24–70.53) 0.312
Neck problem 683 (11.41%) 15.46 (11.23–21.30) 0.233
Muscle problem 434 (7.25%) 9.83 (6.64–14.55) 0.207
Health maintenance or preventive care 254 (4.24%) 5.75 (3.24–10.22) 0.251
Back syndrome with radiating pain 215 (3.59%) 4.87 (2.91–8.14) 0.165
Musculoskeletal symptom or complaint, or other 219 (3.66%) 4.96 (2.39–10.28) 0.350
Headache 179 (2.99%) 4.05 (2.87–5.71) 0.053
Sprain or strain of joint 167 (2.79%) 3.78 (2.30–6.22) 0.115
Shoulder problem 87 (1.45%) 1.97 (1.37–2.83) 0.022
Nerve-related problem 62 (1.04%) 1.40 (0.72–2.75) 0.072
General symptom or complaint, other 51 (0.85%) 1.15 (0.22–6.06) 0.407
Bursitis, tendinitis or synovitis 47 (0.79%) 1.06 (0.71–1.60) 0.011
Kyphosis and scoliosis 47 (0.79%) 1.06 (0.65–1.75) 0.023
Foot or toe symptom or complaint 48 (0.80%) 1.09 (0.41–2.87) 0.123
Ankle problem 46 (0.77%) 1.04 (0.40–2.69) 0.112
Osteoarthrosis, other (not spine) 39 (0.65%) 0.88 (0.51–1.53) 0.023
Hip symptom or complaint 35 (0.58%) 0.79 (0.53–1.19) 0.006
Leg or thigh symptom or complaint 35 (0.58%) 0.79 (0.49–1.28) 0.012
Musculoskeletal injury 33 (0.55%) 0.75 (0.45–1.24) 0.013
Depression 29 (0.48%) 0.66 (0.10–4.23) 0.288

These findings are impressive in that they suggest that most Australian chiropractors treat non-spinal conditions for which there is no evidence that the most frequently used interventions are effective. The treatments employed are depicted in this graph:
Distribution of techniques and care provided by chiropractors, with 95% CI


[Activator = hand-held spring-loaded device that delivers an impulse to the spine. Drop piece = chiropractic treatment table with a segmented drop system which quickly lowers the section of the patient’s body corresponding with the spinal region being treated. Blocks = wedge-shaped blocks placed under the pelvis.

Chiro system = chiropractic system of care, eg, Applied Kinesiology, Sacro-Occipital Technique, Neuroemotional Technique. Flexion distraction = chiropractic treatment table that flexes in the middle to provide traction and mobilisation to the lumbar spine.]

There is no good evidence I know of demonstrating these techniques to be effective for the majority of the conditions listed in the above table.

A similar bone of contention is the frequent use of ‘maintenance’ and ‘wellness’ care. The authors of the article comment: The common use of maintenance and wellness-related terms reflects current debate in the chiropractic profession. “Chiropractic wellness care” is considered by an indeterminate proportion of the profession as an integral part of chiropractic practice, with the belief that regular chiropractic care may have value in maintaining and promoting health, as well as preventing disease. The definition of wellness chiropractic care is controversial, with some chiropractors promoting only spine care as a form of wellness, and others promoting evidence-based health promotion, eg, smoking cessation and weight reduction, alongside spine care. A 2011 consensus process in the chiropractic profession in the United States emphasised that wellness practice must include health promotion and education, and active strategies to foster positive changes in health behaviours. My own systematic review of regular chiropractic care, however, shows that the claimed effects are totally unproven.

One does not need to be overly critical to conclude from all this that the chiropractors surveyed in this investigation earn their daily bread mostly by being economical with the truth regarding the lack of evidence for their actions.

As promised in the last post, I will try to briefly address the issues which make me uncomfortable about the quotes by Anthony Campbell. Readers will recall that Campbell, an ex-director of what was arguably the most influential homeopathic hospital in the world and a long-time editor of the journal HOMEOPATHY, freely admitted that homeopathy was unproven and its effects were most likely not due to any specific properties of the homeopathic remedies [which are, in fact, pure placebos] but largely rely on non-specific effects.

I agree with much that Campbell wrote but I disagree with one particular implication of his conclusions:Homeopathy has not been proved to work but neither has it been conclusively disproven….” and “…it is impossible to say categorically that all the remedies are without objective effect…”

This is an argument, we hear from proponents of alternative medicine with unfailing regularity:MY TREATMENT MAY NOT BE SUPPORTED BY GOOD SCIENCE [BECAUSE GOOD SCIENCE IS EXPENSIVE, AND WE CANNOT AFFORD IT] BUT IT HAS NOT BEEN DISPROVEN EITHER – AND, AS LONG AS IT IS NOT DISPROVEN, NOBODY SHOULD STOP US USING IT”

Campbell does not explicitly draw this latter conclusion but he certainly implies it. In his book, he explains that, even though homeopathic remedies probably are placebos, homeopathy does a lot of good through the placebo effect and through its spiritual aspects. And that is, in his view, sufficient reason to employ it for healing the sick. The very last sentence of his book reads: “Love it or loathe it, homeopathy is here to stay”

So the implication is there: alternative therapies can be as bizarre, nonsensical, implausible, unscientific or idiotic as they like, if we scientists cannot disprove them, they must be legitimate for general use. But there are, of course, two obvious errors in this line of reasoning:

  1. Why on earth should scientists waste their time and resources on testing notions which are clearly bonkers? It is hard to imagine research that is less fruitful than such an endeavour.
  2. Disproving homeopathy [or similarly ridiculous treatments] is a near impossibility. Proving a negative is rarely feasible in science.

In the best interest of patients, responsible health care has to follow an entirely different logic: we must consider any treatment to be unproven, while it is not supported with reasonably sound evidence for effectiveness; and in clinical routine, we employ mostly such treatments which are backed by sound evidence, and we avoid those that are unproven. In other words, whether homeopathy or any other medicine is unproven or disproven is of little practical consequence: we try not to use either category.

While I applaud Campbell’s candid judgement regarding the lack of effectiveness of homeopathic remedies, I feel the need to finish his conclusion for him giving it a dramatically different meaning: Homeopathy has not been proved to work but neither has it been conclusively disproven; this means that, until new evidence unambiguously demonstrates otherwise, we should classify homeopathy as ineffective – and this, of course, applies not just to homeopathy but to ALL unproven interventions.

These days, there is so much hype about alternative cancer treatments that it is hard to find a cancer patient who is not tempted to try this or that alternative medicine. Often it is employed without the knowledge of the oncology team, solely on the advice of non-medically qualified practitioners (NMPs). But is that wise? The aim of this survey was to find out.

Members of several German NMP-associations were invited to complete an online questionnaire. The questionnaire explored areas such as the diagnosis and treatment, goals for using complementary/alternative medicine (CAM), communication with the oncologist, and sources of information.

Of a total of 1,500 members of the NMP associations, 299 took part in this survey. The results show that the treatments employed by NMPs were heterogeneous. Homeopathy was used by 45% of the NMPs, and 10% believed it to be a treatment directly against cancer. Herbal therapy, vitamins, orthomolecular medicine, ordinal therapy, mistletoe preparations, acupuncture, and cancer diets were used by more than 10% of the NMPs. None of the treatments were discussed with the respective physician on a regular basis.

The authors concluded from these findings that many therapies provided by NMPs are biologically based and therefore may interfere with conventional cancer therapy. Thus, patients are at risk of interactions, especially as most NMPs do not adjust their therapies to those of the oncologist. Moreover, risks may arise from these CAM methods as NMPs partly believe them to be useful anticancer treatments. This may lead to the delay or even omission of effective therapies.

Anyone faced with a diagnosis of CANCER is understandably keen to leave no stone unturned to bring about a cure of the disease. Many patients thus go on to the Internet and look what alternative options are on offer. There they find virtually millions of sites advertising thousands of bogus cancer ‘cures’. Others consult their alternative practitioners and seek help. This new survey shows yet again that the advice they receive is dangerous. In fact, it might well be even more dangerous than the results imply: the response rate of the survey was dismal, and I fear that the less responsible NMPs tended not to reply.

None of the treatments listed above can cure cancer. For instance, homeopathy, the most popular alternative cancer treatment in Germany, will have no effect whatsoever on the natural history of the disease. To claim otherwise is criminally irresponsible.

But far too many patients are unaware of the evidence and of the dangers of being misled by bogus claims. What we need, I think, is a major campaign to get the word out. It would be a campaign that saves lives!

Dutch neurologists recently described the case of a 63-year-old female patient presented at their outpatient clinic with a five-week history of severe postural headache, tinnitus and nausea. The onset of these symptoms was concurrent with chiropractic manipulation of the cervical spine which she had tried because of cervical pain.

Cranial MRI showed findings characteristic for intracranial hypotension syndrome. Cervical MRI revealed a large posterior dural tear at the level of C1-2. Following unsuccessful conservative therapy, the patient underwent a lumbar epidural blood patch after which she recovered rapidly.

The authors conclude that manipulation of the cervical spine can cause a dural tear and subsequently an intracranial hypotension syndrome. Postural headaches directly after spinal manipulation should therefore be a reason to suspect this complication. If conservative management fails, an epidural blood patch may be performed.

Quite obviously, this is sound advice that can save lives. The trouble, however, is that the chiropractic profession is, by and large, still in denial. A recent systematic review by a chiropractor included eight cases of intracranial hypotension (IH) and concluded that case reports on IH and spinal manipulative therapy (SMT) have very limited clinical details and therefore cannot exclude other theories or plausible alternatives to explain the IH. To date, the evidence that cervical SMT is not a cause of IH is inconclusive. Further research is required before making any conclusions that cervical SMT is a cause of IH. Chiropractors and other health practitioners should be vigilant in recording established risk factors for IH in all cases. It is possible that the published cases of cervical SMT and IH may have missed important confounding risk factors (e.g. a new headache, or minor neck trauma in young or middle-aged adults).

Instead of distracting us from the fact that chiropractic can lead to serious adverse events, chiropractors would be well-advised to face the music, admit that their treatments are not risk-free and conduct rigorous research with a view of minimizing the harm.

The news that the use of Traditional Chinese Medicine (TCM) positively affects cancer survival might come as a surprise to many readers of this blog; but this is exactly what recent research has suggested. As it was published in one of the leading cancer journals, we should be able to trust the findings – or shouldn’t we?

The authors of this new study used the Taiwan National Health Insurance Research Database to conduct a retrospective population-based cohort study of patients with advanced breast cancer between 2001 and 2010. The patients were separated into TCM users and non-users, and the association between the use of TCM and patient survival was determined.

A total of 729 patients with advanced breast cancer receiving taxanes were included. Their mean age was 52.0 years; 115 patients were TCM users (15.8%) and 614 patients were TCM non-users. The mean follow-up was 2.8 years, with 277 deaths reported to occur during the 10-year period. Multivariate analysis demonstrated that, compared with non-users, the use of TCM was associated with a significantly decreased risk of all-cause mortality (adjusted hazards ratio [HR], 0.55 [95% confidence interval, 0.33-0.90] for TCM use of 30-180 days; adjusted HR, 0.46 [95% confidence interval, 0.27-0.78] for TCM use of > 180 days). Among the frequently used TCMs, those found to be most effective (lowest HRs) in reducing mortality were Bai Hua She She Cao, Ban Zhi Lian, and Huang Qi.

The authors of this paper are initially quite cautious and use adequate terminology when they write that TCM-use was associated with increased survival. But then they seem to get carried away by their enthusiasm and even name the TCM drugs which they thought were most effective in prolonging cancer survival. It is obvious that such causal extrapolations are well out of line with the evidence they produced (oh, how I wished that journal editors would finally wake up to such misleading language!) .

Of course, it is possible that some TCM drugs are effective cancer cures – but the data presented here certainly do NOT demonstrate anything like such an effect. And before such a far-reaching claim is being made, much more and much better research would be necessary.

The thing is, there are many alternative and plausible explanations for the observed phenomenon. For instance, it is conceivable that users and non-users of TCM in this study differed in many ways other than their medication, e.g. severity of cancer, adherence to conventional therapies, life-style, etc. And even if the researchers have used clever statistical methods to control for some of these variables, residual confounding can never be ruled out in such case-control studies.

Correlation is not causation, they say. Neglect of this elementary axiom makes for very poor science – in fact, it produces dangerous pseudoscience which could, like in the present case, lead a cancer patient straight up the garden path towards a premature death.

When we talk about conflicts of interest, we usually think of financial concerns. But conflicts of interests also extend to non-financial matters, such as strong beliefs. These are important in alternative medicine – I would even go as far as to claim that they dominate this field.

My detractors have often claimed that this is where my problem lies. They are convinced that, in 1993, I came into the job as PROFESSOR OF COMPLEMENTARY MEDICINE with an axe to grind; I was determined or perhaps even paid to show that all alternative medicine is utter hocus-pocus, they say. The truth is that, if anything, I was on the side of alternative medicine – and I can prove it. Using the example of homeopathy, I have dedicated an entire article to demonstrate that the myth is untrue – I was not closed-minded or out to ditch homeopathy (or any other form of alternative medicine for that matter).

What then could constitute my ‘conflict of interest’? Surely, he was bribed, I hear them say. Just look at the funds he took from industry. Some of those people have even gone to the trouble of running freedom of information requests to obtain the precise figures for my research-funding. Subsequently they triumphantly publish them and say: Look he got £x from this company and £y from that firm. And they are, of course, correct: I did receive support from commercially interested parties on several occasions. But what my detractors forget is that these were all pro-alternative medicine institutions. More importantly, I always made very sure that no strings were attached with any funds we accepted.

Our core funds came from ‘The Laing Foundation’ which endowed Exeter University with £ 1.5 million. This was done with the understanding that Exeter would put the same amount again into the kitty (which they never did). Anyone who can do simple arithmetic can tell that, to sustain up to 20 staff for almost 20 years, £1.5 million is not nearly enough. There must have been other sources. Who exactly gave money?

Despite utterly useless fundraising by the University, we did manage to obtain additional funds. I managed to receive support in the form of multiple research fellowships, for instance. It came from various sources; for instance, manufacturers of herbal medicines, Boots, the Pilkington Family Trust (yes, the glass manufacturers).

A hugely helpful contributor to our work was the sizable number (I estimate around 30) of visitors from abroad who came on their own money simply because they wanted to learn from and with us. They stayed between 3 months and 4 years, and importantly contributed to our research, knowledge and fun.

In addition, we soon devised ways to generate our own money. For instance, we started an annual conference for researchers in our field which ran for 14 successful years. As we managed everything on a shoestring and did all the organisation ourselves, we made a tidy profit each year which, of course, went straight back into our research. We also published several books which generated some revenue for the same purpose.

And then we received research funding for specific projects, for instance, from THE PRINCE OF WALES’ FOUNDATION FOR INTEGRATED HEALTH, a Japanese organisation supporting Jorhei Healing, THE WELCOME TRUST, the NHS, and even a homeopathic company.

So, do I have a conflict of interest? Did I take money from anyone who might have wanted to ditch alternative medicine? I don’t think so! And if I tell you that, when I came to Exeter in 1993, I donated ~£120 000 of my own funds towards the research of my unit, even my detractors might, for once, be embarrassed to have thought otherwise.

The most widely used definition of EVIDENCE-BASED MEDICINE (EBM) is probably this one: The judicious use of the best current available scientific research in making decisions about the care of patients. Evidence-based medicine (EBM) is intended to integrate clinical expertise with the research evidence and patient values.

David Sackett’s own definition is a little different: Evidence based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. The practice of evidence based medicine means integrating individual clinical expertise with the best available external clinical evidence from systematic research.

Even though the principles of EBM are now widely accepted, there are those who point out that EBM has its limitations. The major criticisms of EBM relate to five themes: reliance on empiricism, narrow definition of evidence, lack of evidence of efficacy, limited usefulness for individual patients, and threats to the autonomy of the doctor/patient relationship.

Advocates of alternative medicine have been particularly vocal in pointing out that EBM is not really applicable to their area. However, as their arguments were less than convincing, a new strategy for dealing with EBM seemed necessary. Some proponents of alternative medicine therefore are now trying to hoist EBM-advocates by their own petard.

In doing so they refer directly to the definitions of EBM and argue that EBM has to fulfil at least three criteria: 1) external best evidence, 2) clinical expertise and 3) patient values or preferences.

Using this argument, they thrive to demonstrate that almost everything in alternative medicine is evidence-based. Let me explain this with two deliberately extreme examples.

CRYSTAL THERAPY FOR CURING CANCER

There is, of course, not a jot of evidence for this. But there may well be the opinion held by crystal therapist that some cancer patients respond to their treatment. Thus the ‘best’ available evidence is clearly positive, they argue. Certainly the clinical expertise of these crystal therapists is positive. So, if a cancer patient wants crystal therapy, all three preconditions are fulfilled and CRYSTAL THERAPY IS ENTIRELY EVIDENCE-BASED.

CHIROPRACTIC FOR ASTHMA

Even the most optimistic chiropractor would find it hard to deny that the best evidence does not demonstrate the effectiveness of chiropractic for asthma. But never mind, the clinical expertise of the chiropractor may well be positive. If the patient has a preference for chiropractic, at least two of the three conditions are fulfilled. Therefore – on balance – chiropractic for asthma is [fairly] evidence-based.

The ‘HOISTING ON THE PETARD OF EBM’-method is thus a perfect technique for turning the principles of EBM upside down. Its application leads us straight back into the dark ages of medicine when anything was legitimate as long as some charlatan could convince his patients to endure his quackery and pay for it – if necessary with his life.

Do you think that chiropractic is effective for asthma? I don’t – in fact, I know it isn’t because, in 2009, I have published a systematic review of the available RCTs which showed quite clearly that the best evidence suggested chiropractic was ineffective for that condition.

But this is clearly not true, might some enthusiasts reply. What is more, they can even refer to a 2010 systematic review which indicates that chiropractic is effective; its conclusions speak a very clear language: …the eight retrieved studies indicated that chiropractic care showed improvements in subjective measures and, to a lesser degree objective measures… How on earth can this be?

I would not be surprised, if chiropractors claimed the discrepancy is due to the fact that Prof Ernst is biased. Others might point out that the more recent review includes more studies and thus ought to be more reliable. The newer review does, in fact, have about twice the number of studies than mine.

How come? Were plenty of new RCTs published during the 12 months that lay between the two publications? The answer is NO. But why then the discrepant conclusions?

The answer is much less puzzling than you might think. The ‘alchemists of alternative medicine’ regularly succeed in smuggling non-evidence into such reviews in order to beautify the overall picture and confirm their wishful thinking. The case of chiropractic for asthma does by no means stand alone, but it is a classic example of how we are being misled by charlatans.

Anyone who reads the full text of the two reviews mentioned above will find that they do, in fact, include exactly the same amount of RCTs. The reason why they arrive at different conclusions is simple: the enthusiasts’ review added NON-EVIDENCE to the existing RCTs. To be precise, the authors included one case series, one case study, one survey, two randomized controlled trials (RCTs), one randomized patient and observer blinded cross-over trial, one single blind cross study design, and one self-reported impairment questionnaire.

Now, there is nothing wrong with case reports, case series, or surveys – except THEY TELL US NOTHING ABOUT EFFECTIVENESS. I would bet my last shirt that the authors know all of that; yet they make fairly firm and positive conclusions about effectiveness. As the RCT-results collectively happen to be negative, they even pretend that case reports etc. outweigh the findings of RCTs.

And why do they do that? Because they are interested in the truth, or because they don’t mind using alchemy in order to mislead us? Your guess is as good as mine.

Systematic reviews are widely considered to be the most reliable type of evidence for judging the effectiveness of therapeutic interventions. Such reviews should be focused on a well-defined research question and identify, critically appraise and synthesize the totality of the high quality research evidence relevant to that question. Often it is possible to pool the data from individual studies and thus create a new numerical result of the existing evidence; in this case, we speak of a meta-analysis, a sub-category of systematic reviews.

One strength of systematic review is that they minimise selection and random biases by considering at the totality of the evidence of a pre-defined nature and quality. A crucial precondition, however, is that the quality of the primary studies is critically assessed. If this is done well, the researchers will usually be able to determine how robust any given result is, and whether high quality trials generate similar findings as those of lower quality. If there is a discrepancy between findings from rigorous and flimsy studies, it is obviously advisable to trust the former and discard the latter.

And this is where systematic reviews of alternative treatments can run into difficulties. For any given research question in this area we usually have a paucity of primary studies. Equally important is the fact that many of the available trials tend to be of low quality. Consequently, there often is a lack of high quality studies, and this makes it all the more important to include a robust critical evaluation of the primary data. Not doing so would render the overall result of the review less than reliable – in fact, such a paper would not qualify as a systematic review at all; it would be a pseudo-systematic review, i.e. a review which pretends to be systematic but, in fact, is not. Such papers are a menace in that they can seriously mislead us, particularly if we are not familiar with the essential requirements for a reliable review.

This is precisely where some promoters of bogus treatments seem to see their opportunity of making their unproven therapy look as though it was evidence-based. Pseudo-systematic reviews can be manipulated to yield a desired outcome. In my last post, I have shown that this can be done by including treatments which are effective so that an ineffective therapy appears effective (“chiropractic is so much more than just spinal manipulation”). An even simpler method is to exclude some of the studies that contradict one’s belief from the review. Obviously, the review would then not comprise the totality of the available evidence. But, unless the reader bothers to do a considerable amount of research, he/she would be highly unlikely to notice. All one needs to do is to smuggle the paper past the peer-review process – hardly a difficult task, given the plethora of alternative medicine journals that bend over backwards to publish any rubbish as long as it promotes alternative medicine.

Alternatively (or in addition) one can save oneself a lot of work and omit the process of critically evaluating the primary studies. This method is increasingly popular in alternative medicine. It is a fool-proof method of generating a false-positive overall result. As poor quality trials have a tendency to deliver false-positive results, it is obvious that a predominance of flimsy studies must create a false-positive result.

A particularly notorious example of a pseudo-systematic review that used this as well as most of the other tricks for misleading the reader is the famous ‘systematic’ review by Bronfort et al. It was commissioned by the UK GENERAL CHIROPRACTIC COUNCIL after the chiropractic profession got into trouble and was keen to defend those bogus treatments disclosed by Simon Singh. Bronfort and his colleagues thus swiftly published (of course, in a chiro-journal) an all-encompassing review attempting to show that, at least for some conditions, chiropractic was effective. Its lengthy conclusions seemed encouraging: Spinal manipulation/mobilization is effective in adults for: acute, subacute, and chronic low back pain; migraine and cervicogenic headache; cervicogenic dizziness; manipulation/mobilization is effective for several extremity joint conditions; and thoracic manipulation/mobilization is effective for acute/subacute neck pain. The evidence is inconclusive for cervical manipulation/mobilization alone for neck pain of any duration, and for manipulation/mobilization for mid back pain, sciatica, tension-type headache, coccydynia, temporomandibular joint disorders, fibromyalgia, premenstrual syndrome, and pneumonia in older adults. Spinal manipulation is not effective for asthma and dysmenorrhea when compared to sham manipulation, or for Stage 1 hypertension when added to an antihypertensive diet. In children, the evidence is inconclusive regarding the effectiveness for otitis media and enuresis, and it is not effective for infantile colic and asthma when compared to sham manipulation. Massage is effective in adults for chronic low back pain and chronic neck pain. The evidence is inconclusive for knee osteoarthritis, fibromyalgia, myofascial pain syndrome, migraine headache, and premenstrual syndrome. In children, the evidence is inconclusive for asthma and infantile colic. 

Chiropractors across the world cite this paper as evidence that chiropractic has at least some evidence base. What they omit to tell us (perhaps because they do not appreciate it themselves) is the fact that Bronfort et al

  • failed to formulate a focussed research question,
  • invented his own categories of inconclusive findings,
  • included all sorts of studies which had nothing to do with chiropractic,
  • and did not to make an assessment of the quality of the included primary studies they included in their review.

If, for a certain condition, three trials were included, for instance, two of which were positive but of poor quality and one was negative but of good quality, the authors would conclude that, overall, there is sound evidence.

Bronfort himself is, of course, more than likely to know all that (he has learnt his trade with an excellent Dutch research team and published several high quality reviews) - but his readers mostly don’t. And for chiropractors, this ‘systematic’ review is now considered to be the most reliable evidence in their field.

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