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What Does “Scientifically Proven” Really Mean?
Science as a Brand
I think of science as primarily an approach to knowledge; both a philosophy and collection of methods for developing an understanding of reality. Of course science is imperfect, both in itself and in how it is practiced by imperfect human beings. But the evidence of history is overwhelming and not rationally deniable that a scientific approach to health and disease works better than any other approach tried so far.
Largely because of the dramatic successes of scientific medicine, the label of “scientifically proven” has also become a potent marketing tool. There may be suspicion of scientists and technology, and plenty of interest in vague and comforting alternative philosophies, but when the chips are down people throughout the world trust science and scientific medicine more as the most reliable source of information and healthcare.
This is why even those dedicated to ideologies clearly incompatible with science, such as homeopaths, attempt to label their practices as scientifically validated.
Because of this, it is nearly impossible to find advertising for a healthcare product or service that does not claim the product is “scientifically proven” to work. Unfortunately, most of those who use this language to market their wares do not appear to know, or to care, what it actually means, and the information to judge the truth of the claim is rarely made available to consumers.
Can We Ever Really Prove Anything?
It is often said that nothing is ever absolutely proven in science. This is true to some extent in that, contrary to anti-science propaganda, science as a method is quite open-minded and aware of the limitations of human reason, and so the method allows for the possibility that any idea, no matter how established and venerated, can be proven false with adequate evidence. However, realistically there are some propositions that achieve a level of supporting evidence that makes any serious doubt about their truth perverse and irrational. I have no fear of being wrong when I say the Earth is not flat nor poised on the back of a turtle.
Similarly, it is often said that the absence of evidence is not evidence of absence, meaning that something as yet not thoroughly tested scientifically cannot be dismissed as false, only regarded as unproven. This is certainly true as well. Unfortunately, in the marketing of unconventional healthcare products this idea is often twisted into a claim that nothing can be regarded as false without an unachievable standard of voluminous and perfect quality evidence against it. But in the real world, we can’t have perfect evidence for everything, and we must apportion our limited resources rationally.
Homeopathy, for example, has a theory that cannot be true unless much of established science is wrong; the in vitro evidence of biologic effects or water memory is overwhelmingly negative; the lab animal and human clinical trials and the few veterinary clinical trials are overwhelmingly negative, with a strong correlation between the quality of the study and the failure to find a beneficial effect. It has been exhaustively evaluated for over a century without generating compelling scientific evidence that it works. Adding all this up, it is more than reasonable to dismiss it as a failed idea and move on without insisting that without more evidence we cannot “prove” homeopathy is a waste of time.
Sorry, Reality Really is Messy
So when deciding whether or not to trust a claim that something is scientifically proven, it is important to have some idea what such a claim might actually mean, if true, and what level of evidence is necessary to reasonably make it. To begin with, the level of evidence available in medicine rarely reaches the degree of certainty of that for the hypothesis that the Earth is round and not balanced on a turtle. Therefore, reliable science-based claims for medical services should usually be circumspect and should reflect the degree of supporting data. “Scientifically proven to treat cancer with no side effects!” is not a claim that is very likely to be supportable through real evidence. “May relieve the symptoms of cancer therapy in some patients with few side effects” is far more likely to be true.
An especially frustrating conundrum for proponents of science-based medicine is that it is far easier to sell something with strong, confident, absolute claims that are probably not true than with measured, realistic assessments supported by good evidence. Ambiguity and complexity are far less attractive than simple, confident narratives. And statistics and the details of scientific evidence are less compelling to potential customers than heartwarming testimonials with far less real evidentiary value. This gives faith-based medicine a significant public relations advantage over science-based medicine and skepticism. But the fact remains that truth is messy and full of uncertainty, and if someone is selling you something as extremely simple, clear-cut, and too good to be true, they probably are selling you a hope or a fantasy, not a real medical therapy.
The Hierarchy of Evidence
The core of evidence-based medicine is the idea that not all evidence is created equal. There are levels of evidence ranging from the suggestive but not very reliable to the solid and trustworthy, though never perfect. When reading a claim that something is “scientifically proven,” you should try to find out what kind of evidence supports the claim, and make your acceptance of the claim proportional to the quality and quantity of the evidence provided.
One key principle to bear in mind is that we are by nature inclined to generate and trust evidence that confirms our beliefs. Even the smartest and most honest scientists have deep, unconscious biases in favor of their own ideas, and these biases influence how they conduct their work and how they interpret data. And such biases extend even beyond the individual. For example, it is generally far easier to publish, and publicize, studies that show a positive result than those that show a promising treatment doesn’t work. In some countries, such publication bias is so severe that negative studies are effectively never reported.
Therefore, a key principle in evaluating medical claims is Negative Evidence is More Reliable than Positive Evidence!!!! Sure, if you have ten studies by different researchers in different parts of the world, including some that deliberately set out to disprove the findings of earlier researchers, and they all get the same answer, you can be pretty sure that is the right answer. But when the evidence is conflicting, when early studies look better than later ones, when low quality studies are positive and better ones negative, or when only one research group can get positive results, the better bet by far is that the treatment being studied doesn’t work.
The following is a simplified list of kinds of evidence commonly encountered and how they ought to be interpreted. In general, the list goes from least reliable to most reliable.
1. Mere opinion– Bias and cognitive blind spots are part of being human, and they affect everybody no matter how smart or well-educated. Linus Pauling, for example, was a brilliant scientist, and arguably a really good person who won a Nobel Prize for chemistry and a Nobel Peace Prize. He was also spectacularly and obstinately wrong about the health benefits of megadoses of Vitamin C. While those who make no effort to acknowledge or control their own biases and rely entirely on faith are especially vulnerable to errors in judgment, absolutely no one is immune. So if the only evidence for a medical claim is that someone smart, kind, famous, or otherwise admirable believes it, the claim should be viewed very skeptically since this kind of evidence is deeply and persistently unreliable.
2. Testimonials– Testimonials are just stories people tell about their experiences and how they interpret them. They are not controlled in any way for bias or error, and they are highly unreliable. Testimonials are also subject to a kind of publication bias in that no one marketing a medical product or service is going to seek out, collect, and report every person’s experience. Positive stories are promoted as evidence the product works, and negative stories are ignored, suppressed, or explained away. Though the most common and emotionally compelling kind of evidence offered to sell medical products, testimonials are not scientific or trustworthy and deserve to be ignored.
3. Reasoning from First Principles– Sometimes marketers will tout something as scientifically proven and then describe some features of basic chemistry, physics, physiology, and so on to suggest how their product might work and why you should believe it does. Certainly, a theory based on established scientific principles is a lot more likely to be true than one which is not compatible with well-established knowledge. However, living organisms are complex and extrapolating from basic science to actual patients is risky and unreliable. Just because something makes sense or ought to work based on a plausible theory does not mean it actually does. This is one of those bits of evidence that is necessary but not sufficient to demonstrate a therapy is useful.
4. Test Tubes and Guinea Pigs – Basic preclinical research into a promising medical treatment begins with testing the underlying theory behind an idea. If a proposed cure for cancer doesn’t kill cancer cells in a test tube, it’s probably not worth giving to patients. But again just because something works in the simplified, controlled environment of the lab doesn’t mean it will be safe or effective in living animals. Bleach kills cancer in the test tube, but that doesn’t mean we should drink it or inject it into people or pets with cancer! Similarly, all mammals have a lot in common, so if it kills rats it could be dangerous for dogs or people, and if it cures cancer in mice, it might be useful for cancer in cats and cows. But, there are also important differences between species, and it is never appropriate to simply assume the results seen in one species will also be seen in another. This again is a type of evidence necessary to demonstrate a treatment could work, but not sufficient to claim it does.
5. Clinical Trials– This is a huge category of ways of investigating a medical treatment with many levels of reliability. Rather than describe all the different kinds of studies and their pros and cons, I will list some general factors that are useful in deciding whether the existence of a positive clinical trial justifies calling a product “scientifically proven.”
A. Strength in Numbers- Small trials are less reliable than large trials. A few trials are less reliable than many trials. Trials conducted by a couple of investigators or all in the same place are less trustworthy than trials conducted in multiple locations by many different investigators. Individual case studies or small case series are less reliable than larger group studies. In general, the credence given to clinical studies should be proportional to the size and number of the studies.
B. Controls for Bias- The more layers of control in place to minimize potential bias, the more likely the result is believable. Such controls include:
Treatment, Placebo, and No Treatment Groups
Random assignment of subject to these groups
Blinding so that as few people as possible, especially patients and those evaluating them, know who is in which group
C. Replication and Persistence- Since we all tend to see what we expect to see, even with the most honest intentions, individual studies are almost never the last word on a medical subject, especially positive studies that find what the investigators want and expect to find. A key feature to demonstrating something really works is repeated testing by different investigators in different populations. It is especially convincing when someone sets out to disprove the results of a previous study and ends up getting the same results as the original, because this requires data robust enough to contradict the biases of the researchers involved.
The Decline Effect is a phenomenon in which early studies of a new intervention look very impressive, and as further studies are done the results get less and less positive until the original effect essentially goes away. This most likely represents the scientific process gradually correcting an initial erroneous finding through attempts to replicate it. Because of this effect, single studies are rarely to be trusted as the final word on a scientific hypothesis. A true idea, a really effective therapy will withstand repeated testing and will continue to accumulate positive evidence, while a promising idea that isn’t actually true will fail to hold up to prolonged, repeated scrutiny. This is part of why systematic reviews, which are methodologically formalized surveys of the totality of the evidence provided by individual studies, are a more reliable indicator of the truth behind a claim than any of the individual studies themselves.
The Bottom Line
Because most people understand that science works better than any other method for determining which medical claims are true and which are false, promoting a therapy as “scientifically proven” is a powerful marketing tool. However, the level of evidence usually available in medicine rarely justifies sweeping, absolute claims. Less dramatic, more qualified and realistic claims are more likely to be true. And not all evidence is created equal. Some of the most common and emotionally compelling kinds of evidence used in medical advertising, such as the opinions of smart, famous people and the testimonials of satisfied customers, are actually the least reliable and most misleading kinds of evidence.
Even truly scientific evidence varies from merely suggestive to pretty clear and definitive. A plausible theory and preclinical research in test tubes and animal models are necessary to show a medical treatment could work, but they are not sufficient to prove it really does work. And even evidence from published clinical trials must be given credence in proportion to the size, number, and quality of the studies that support a claim. Finally, since our biases are almost always in favor of confirming what we already believe to be true, negative evidence is far more reliable than positive evidence.
Posted in General, Science-Based Veterinary Medicine
4 Comments
Web of Trust and the WOT Project
Web of Trust (WOT) is a crowdsourced ratings system that rates the safety and reliability of web sites. These ratings are generated by users who visit the sites. They can be based on security concerns, but they are mostly based on ratings from individuals who either like or dislike the content. WOT has been integrated into Facebook so that when Facebook users click on a link to a site with a poor WOT reputation, they are warned the site may be unreliable. This has a great potential to influence the traffic to a web site.
WOT can be both useful and problematic for skeptics. It is useful for us to be able to rate and comment on sites that offer unreliable, unscientific information on alternative medicine, for example. However, it also provides an opportunity for those who don’t like our message to rate our sites negatively, which can discourage those seeking information from coming to them.
Tim Farley, of the site What’s the Harm? and Erik Davis of Skeptic North have discussed the potential positive and negative effects of WOT on the ability of skeptics to educate the public, and Erik has created the WOT Project, an effort to identify reliable skeptical web sites and encourage skeptics to rate them positively so that their information will be more readily available.
This project is currently of particular interest to me since after reading about it I discovered that the SkeptVet and SkeptVet Blog have poor WOT reputations. Partly this stems from a hacking issue which I only became aware of several months ago when my host notified me that my site had been cleaned of some malware and that I had to reset all of my passwords. The blacklisting site that originally flagged my domain has since removed it’s warning.
But I also have had a small number of ratings by individuals (18) which are all negative. I suspect this is the work of CAM proponents angered by the content of my posts. So as well as encouraging everyone to participate in the WOT Project in general, I would like to ask readers who believe the content here is useful to got to the SkeptVet WOT profile and provide a positive rating and comment. Hopefully, this will help prevent those who see the site when searching for information about alternative veterinary medicine from being warned away from it by WOT.
Thanks!
Posted in General
13 Comments
Another Homeopathy Lawsuit-This time one that at least makes sense!
There has certainly been a lot of talk lately about homeopathy and lawsuits. I have discussed the Academy of Veterinary Homeopathy’s attempt to obtain through litigation the legitimacy they can’t achieve by proving their methods work through scientific research. And Science-Based Medicine had an article today about the French company Boiron suing an Italian blogger for pointing out that their product Oscillo is nothing but a sugar pill and cannot possibly be useful for treating flu symptoms. So I admit I was a little bit ambivalent to see the tables turned by a lawsuit in California, accusing Boiron of fraud for implying Oscillo has therapeutic effects. In general, I don’t believe the courts are the best place to adjudicate disputes about the scientific merits of medical therapies. However, it is true that homeopathy cannot be viewed as anything other than delusion or fraud, and it is satisfying to see someone has the courage to point out that there can be no reasonable justification for profiting from selling homeopathic products.
The complaint is succinct and illustrates starkly how ridiculous it is to market any homeopathic remedy as if it were medicine.
Oscillococcinum (the “Ocillo”) is nothing more than a sugar pill that Defendants falsely advertise has the ability to cure the flu. In reality, Oscillo has no impact on the flu or any symptoms that accompany the flu…
The truth is that the listed active ingredient in Oscillo, Anas Barbariae Hepatis et Cordis Extractum, is neither active in combating the flu nor is it actually an ingredient in Oscillo… Anas Barbariae Hepatis et Cordis Extractum has no known medicinal quality, further, in the extreme dilution claimed by Defendants, it has no impact on the human body whatsoever because it is not present in Oscillo.
Defendants claim that the active ingredient in Oscillo, Anas Barbariae Hepatis et Cordis Extractum, is diluted to 200CK…At this purported dilution, the probability of getting 1 molecule of the active ingredient of Oscillo in a regular dosage is approximately equal to winning the Powerball every week for an[sic] nearly an entire year…
Defendants are fully aware that there is no Anas Barbariae Hepatis et Cordis Extractum present in Oscillo. In an interview with the U.S. News and World Report, Defendants stated, “[of] course its safe. There’s nothing in it.”
…Defendants sell Oscillo for approximately $10 per unit based on the preceding false advertising claims. As a result, Defendants have wrongfully taken milloons of dollars from California consumers.
I am not optimistic that the suit will be successful or meaningfully impact the marketing of water as medicine. But as a matter of principle, and as an opportunity to educate the public, the lawsuit is worthwhile, and I applaud the plaintiff for making his efforts.
Posted in Homeopathy, Law, Regulation, and Politics
4 Comments
Academy of Veterinary Homeopathy Lawsuit Update
Back in May, I wrote about a lawsuit involving the Academy of Veterinary Homeopathy (AVH) and the American Association of Veterinary State Boards (AAVSB) committee that certifies continuing education courses veterinarians must take to maintain their state licensure (the RACE committee). In brief, the RACE committee changed their standards for approving continuing education programs to require some minimal standards of scientific legitimacy for veterinary continuing education. The standards requires approved courses,
build upon or refresh the participant in the standards for practice and the foundational, evidence-based material presented in accredited colleges or schools of veterinary medicine or accredited veterinary technician programs…CE programs that advocate unscientific modalities of diagnosis or therapy are not eligible for RACE approval…All scientific information referred to, reported or used in RACE Program Applications in support or justification of an animal-care recommendation must conform to the medically accepted and scientifically supported standards of experimental design, data collection and analysis.
As I’ve discussed in detail before, homeopathy cannot by any but the most absurd contortions of reason be viewed as a scientifically legitimate or validated approach to health care, so it is not surprising that once RACE ceased rubber stamping applications for approval and applied these reasonable standards, homeopathy courses were judged ineligible for continuing education credit. It is also not surprising, of course, that homeopaths and others practicing scientifically questionable veterinary medical methods would object.
What is surprising and disturbing, however, is that the limited media coverage of the AVH lawsuit has been generally biased in favor of the AVH position, and there has been virtually no criticism of the deeply anti-science stance of the AVH, which if successful will essentially end all meaningful regulation of veterinary continuing education. Like much media coverage of creationism, journalists seem to believe that fair coverage requires ignoring the overwhelming consensus among scientists and veterinarians that homeopathy is nonsense and presenting veterinary homeopaths as a legitimate minority community being unjustly discriminated against. The media reports I have seen so far seem to entirely ignore the underlying issue of the scientific evidence against homeopathy or the threat the lawsuit, if successful, poses to the very idea of regulating the standard of veterinary care through the process of state licensure.
The Media Gets It Wrong
The Veterinary Practice News reported on this lawsuit in early August. In a roughly 2000 word article, the author extensively quoted five supporters of homeopathy and of the lawsuit. She also quoted an official at the AAVSB who was not free to comment on pending litigation. And finally, she interviewed me for the article as the sole critic of the AVH position.
I was quoted as saying that homeopathy was not a science-based intervention, which is accurate. I was also quoted as saying that, “Alternative medicine providers are often better at treating psychological aspects of a medical incident an owner is dealing with, and there’s no doubt they are caring and compassionate…”This is partially correct in that I did acknowledge that alternative practitioners are undoubtedly as caring and compassionate as other veterinarians, but it misrepresents the point I was making that the reason methods like homeopathy are popular with a small percentage of the pet-owning public is not because they actually work but because of the psychological effects, essentially a placebo-by-proxy, that the interaction with the practitioner has on the owner.
Lastly, I was quoted as saying that, “these therapies are not taught in veterinary schools.” This is followed by a “gotcha” list of veterinary schools that offer elective courses in “integrative medicine” or have “holistic medicine” student organizations. This is clearly intended to undermine the credibility of my comments. However, this is again a manipulative misrepresentation of my position.
Homeopathy is clearly not part of the core veterinary curriculum, nor is it generally accepted as a valid approach to medicine at U.S. veterinary colleges. The AVH does not dispute this in their complaint. And of the four veterinary schools (out of 28 in the U.S.) mentioned in the article as having “elective courses in CAVM or integrative veterinary medicine,” I could not find any that actually do have a course in homeopathy, though CSU does offer an elective called “Critical Overview of Complementary and Alternative Medicine” taught by Narda Robinson, who is a vocal critic of homeopathy. It is possible, of course, that a couple of schools do have credulous individuals on faculty who teach that homeopathy is scientifically legitimate, but if so these represent a rare minority opinion which is discounted by the overwhelming majority of veterinary scientists. The article was a barely disguised propaganda piece for the AVH position with only a superficial nod towards the idea of journalistic neutrality.
Another article on the subject was released today by the Veterinary Information Network (VIN) News Service. This article is more neutral than the VPN piece, but it still creates a false impression of the nature of the debate. It misrepresents the conflict as a balanced difference of opinion within the profession, when in fact it is about a small group of believers in a long-discredited belief system agitating for a special exemption from the scientific standards normally applied to mainstream veterinary medical practices.
The article extensively quotes the AVH veterinarian and attorney who filed the lawsuit, and also less extensively the president of the AAVSB. In general, much attention is given to the idea that homeopathy and other alternative approaches are “discriminated against,” and almost no attention is given the underlying scientific issue and the question of whether education of licensed veterinarians should be rooted in accepted science.
What’s the Point of Continuing Education for Vets?
I have discussed the legal and historical issues of licensing healthcare providers, including veterinarians, in detail elsewhere. In brief, the state is required to establish standards for the practice of medicine and issue licenses to healthcare providers in order to protect the public health and prevent unsafe and ineffective treatments from being sold as legitimate healthcare. Prior to the development of this practice, quacks and charlatans routinely sold useless or harmful, even deadly “remedies” freely, to the great harm of patients in need of real care. Continuing education requirements are part of this system, and they are intended to ensure that veterinarians stay current on progress in veterinary medicine.
It makes no sense to have such standards if there is no reasonable, scientific criteria for what counts as legitimate continuing education. Should veterinarians be able to maintain their licensure by studying anything they want? Psychic surgery, astrology, voodoo, faith healing, etc? The AVH argues that the standard of scientific evidence is fundamentally unfair. According to the VIN article, the new RACE standards’ emphasis on science, “worked to preclude homeopathic courses that were not based on what RACE committee members considered to be clear, evidence-based science. It narrowed the road to acceptance, critics say, giving more weight to published science and less to the experts in homeopathy. ”
This as much as admits that homeopathy is not accepted as scientifically legitimate by anyone but homeopaths. The logical consequence of this, apparently, is that only experts in homeopathy should be allowed to judge if homeopathy is scientifically legitimate. And presumably only psychics, astrologers, and voodoo priests should be allowed to judge whether these are legitimate veterinary medical approaches?
This is a form of special pleading which says that there is no real scientific standard of evidence that can prove anything is or is not effective medicine, so followers of every individual approach should simply be free to judge their own practices by their own standards and then the state should simply endorse their judgments. Such an approach effectively eliminates any meaningful standard of quality for veterinary care and takes us back to the medical anarchism of the 19th century.
Taking this sort of approach even further, the American Holistic Veterinary Medicine Association has formed its own standards group, the Registry of Alternative and Integrative Veterinary Medical Education (RAIVE) to circumvent the RACE standards board with one stacked with believers in alternative therapies and more inclined to rubber stamp continuing education in these approaches. This will be meaningless, of course, unless state veterinary boards agree to accept RAIVE in lieu of RACE approval. Of course, since such boards are fundamentally political, rather than scientific, agencies, and they have a solid history of ignoring blatantly even the most egregiously ridiculous and harmful sorts of medical nonsense so long as it is promulgated by a licensed veterinarian, it seems not unlikely that this separate-and-equal approach to deciding what is legitimate medicine will succeed.
Why Does It Matter?
The simple answer to this is that our patients are better off if they receive effective care. And this is more likely to happen if veterinarians are trained in legitimate scientific medicine. We have a special privilege by virtue of the license we are granted by the state to practice veterinary medicine. We can make our living providing healthcare for animals. And this privilege is granted us with the understanding that we will employ safe, effective, scientifically valid treatments. Our clients come to us trusting that our status as licensed veterinarians means we are meaningfully different from unlicensed individuals who might offer veterinary services. The state has essentially certified that we can be trusted to take proper care of our clients’ companion animals using valid methods.
If any and all methods are considered equally acceptable as support for our licensure, and if only believers in a given method are allowed to judge the legitimacy of that method, regardless of how few they are or how lacking the scientific evidence in support of their beliefs, than licensure is meaningless. A pet owner has no way of knowing if the licensed veterinarian they go to is practicing accepted, scientific medicine or a completely bogus method they have invented and judged legitimate all by themselves.
The harm that unscientific approaches to medicine, including homeopathy, can do is real and easy to illustrate (here and here, for example). The issue behind the AVH lawsuit is not fairness or open-mindedness, it is about whether scientific evidence and regulatory standards are to have any meaning or any influence on the quality of veterinary care the public is offered. The AVH is fundamentally seeking an exemption from any such standards and the right of any group to judge their own beliefs and promote them as legitimate under the imprimatur of state government without interference from the judgment of the rest of the profession or state regulators.
Posted in Homeopathy, Law, Regulation, and Politics
11 Comments
Probiotic Fortiflora: Not apparently very helpful in preventing diarrhea in shelter animals
Probiotics, living microorganisms fed to humans and animals to prevent or treat disease, are an interesting area of ongoing research. I have written about this intervention a number of times (1,2) and it seems a promising area of research, though the current evidence for meaningful beneficial effects is quite limited. There is reasonable evidence for some benefit in treating antibiotic-associated diarrhea or acute diarrhea of unknown cause(3). The evidence is not very good for many other claimed benefits, such as strengthening of immune system function, treatment of kidney disease(4,5), management of feline upper respiratory viral infections(6), and so on. And there are serious problems with irresponsible, excessive hype(7) and poor quality control(8) for probiotics.
Overall, I am cautiously optimistic that we will eventually find legitimate therapeutic uses for some probiotics, though I find the existing evidence unconvincing for most claims currently made about them. A new study looking at the use of Fortiflora, a veterinary probiotic product, for control of diarrhea in shelter animals, does not add much support to the proposed value of this probiotic.
Bybee SN, Scorza AV, Lappin MR. Effect of the Probiotic Enterococcus faecium SF68 on Presence of Diarrhea in Cats and Dogs Housed in an Animal Shelter. J Vet Intern Med. 2011 Jul;25(4):856-60.
Cats in this study were housed for variable periods of time in two rooms, one for previously owned cats and another for feral cats. Canine subjects were also housed in two separate areas. Subjects in both rooms for each species were observed for 4 weeks to establish a baseline incidence of diarrhea in the population. Then subjects in one of the rooms for each species were given Fortiflora daily for 4 weeks while the subjects in the other room were given a placebo. All subjects were taken off the Fortiflora and placebo for one week, and then the treatments were switched, so subjects in the room that had originally received placebo got the Fortiflora and vice versa.
The stool of every animal was scored on a stool consistency chart every day. Abnormal stool samples were evaluated for parasites whenever possible, and an effort was made to evaluate a normal stool from another animal in the same room at the same time to identify what if any role parasites played in the incidence of diarrhea. It is not clear from the paper what if any treatment was given for diarrhea or fecal parasites.
For both dogs and cats, some fecal parasites were detected in some individuals, but the rate of parasitism was no higher in those with diarrhea than in those with normal stools, so the parasites did not seem to influence the incidence of diarrhea significantly in a way that would complicate evaluating the effect of the probiotic. This effect, however, was not especially clear. For the dogs, there was no significant different in the incidence of diarrhea between those getting the Fortiflora and those receiving the placebo regardless of how the data was analyzed. The overall incidence of diarrhea in both groups was lower than expected for reasons that were not identified.
In the cat groups, the overall incidence of diarrhea was no different between the probiotic and placebo groups. However, when the data was broken down to compare the proportion of cats having diarrhea for more than 2 days, this was lower in the probiotic group than in the control group, though the level of significance was not dramatic (P=0.0297 with a cutoff of <0.05).
The authors conclude this finding “suggests the probiotic may have beneficial effects on the gastrointestinal tract.” This is certainly possible, but this particular study provides little support for the idea.
Posted in Herbs and Supplements
3 Comments
Denamarin: Does it prevent chemotherapy-induced liver damage?
Silymarin and s-adensylmethionine (SAM-e) are plant-derived chemicals frequently used as supplements for a wide variety of applications. I’ve written about both before, evaluating the available evidence in humans and in dogs and cats (1,2,3). So far, the evidence concerning the safety and efficacy of these supplements is limited and conflicting. A recent study, however, provides a little bit more low-level support for the use of at least one combination product, known as Denamarin, containing these chemicals.
KA, Hammond GM, Irish AM, Kent MS, Guerrero TA, Rodriguez CO, Griffin DW. Prospective Randomized Clinical Trial Assessing the Efficacy of Denamarin for Prevention of CCNU-Induced Hepatopathy in Tumor-Bearing Dogs. J Vet Intern Med. 2011 Jul;25(4):838-45.
In this study, fifty dogs being treated for various cancers with the chemotherapy agent lomustine (CCNU) were randomly divided into two groups. One group was given Denamarin and the other was not. CCNU is known to frequently cause increases in liver enzymes measured in the blood. Although it is much more rarely the cause of serious liver damage, the elevations in liver enzyme levels often causes concern that can lead to delaying or discontinuing use of the drug. The goal of the study was to see if Denamrin could prevent the increase in liver enzyme levels.
In terms of this narrow criteria, the study showed a positive effect. While only 68% of the dogs on Denamarin showed liver enzyme increased, 86% of those not on the supplement had increased levels of the major enzyme of interest, alanine aminotransferase (ALT). And while these elevations reached the highest levels in 28% of the control dogs, only 7% of the dogs on Denamrin showed such very high increases in ALT.
There are a number of caveats, however, that limit the degree to which these results can support a general recommendation to use Denamarin in dogs given CCNU. The cause of liver enzyme elevations was not determined in most dogs, so it is possible that a progression of the underlying cancer, rather than the CCNU, caused the increases in some of these dogs. And only 1 of the fifty dogs actually showed clinical symptoms associated with liver damage, so it even if Denamarin prevents increased enzyme levels, this may or may not have any actual clinical benefits.
Methodologically, there are some additional caveats that must be considered in judging the significance of this study. There was no placebo group, and owners and investigators were not blinded to the treatment group. While this potential source of bias would not have directly affected ALT measurements, it could potentially have led to differences in how the dogs in the two groups were treated, which might have indirectly affected these levels. This is especially a concern since the study was funded by the manufacturer of Denamarin, and several of the authors have financial links to the company.
Overall, this study provides low-level evidence that Denamarin may have benefits in protecting against CCNU-induced liver damage in dogs with cancer. Independent replication with better controls and more comprehensive assessment of outcome would help to determine if the current results truly represent a clinically meaningful benefit from this supplement or not. However, given the low level of risk associated with this specific product, it is not unreasonable to consider using this supplement for this indication. This does not, of course, translate into support for a generalized use of Denamarin for any and all liver problems.
Posted in Herbs and Supplements
12 Comments
Neoplasene: Benefits Unproven and Risks Severe
Two years ago, I wrote about an herbal product called Neoplasene, an excharotic derived from bloodroot that is marketed for treatment of cancer. I pointed out in that article that apart from a couple of in vitro studies suggesting the active chemical ingredient has some interesting effects on cancer cells, there is little evidence the product is an effective cancer treatment. And there is ample anecdotal and in vitro evidence of harm caused by the product, which kills healthy tissues as well as cancer cells and has been shown in humans to create horrible wounds while leaving hidden cancer that later spreads and kills the patient. No controlled research has been done in dogs and cats, and there is no reliable evidence to support the claims made by the marketers of this product.
Nevertheless, due to the power of anecdotes, and the weakness of government regulation of herbal products, this preparation is still marketed for use, and there are veterinarians who employ it. A recent case report in the Journal of the American Veterinary Medical Association (JAVMA) discusses the lack of evidence supporting the use of bloodroot and illustrates the significant harm these products can do.
Childress, MO. Burgess, RC. Holland, CH. Gelb, HR. Consequences of intratumoral injection of a herbal preparation containing bloodroot (Sanguinaria canadensis) extract in two dogs. Journal of the American Veterinary Medical Association 2011;239(3):374-379.
The report discusses two dogs, belonging to the same owner, who had Neoplasene injected into skin tumors. The first, a 2 year old golden retriever, had a benign tumor about 2cm in diameter. Such masses usually cause no problem for dogs, but if they are disturbing to owners or if they become injured or infected, they can be easily removed surgically, which is curative. Unfortunately, the treating veterinarian elected to inject the mass with Neoplasene. Six days later, the tumor had become bruised and much larger. The veterinarian instructed the client to give an oral homeopathic remedy to reduce the swelling of the tumor (which, given the mountain of evidence that homeopathy is nothing more than water and a bit of placebo effect, cannot reasonably viewed as an acceptable standard of care). After the swelling failed to resolve following drainage and bandaging, the pet was taken to the hospital of the veterinary medical school at Purdue University. By this time the benign 2cm diameter mass had become a 6cm area of severely inflammed and necrotic (dead) tissue.
The dog had surgery to remove the mass and a margin of healthy tissue around it, which involved a very extensive surgical procedure. After many weeks involving several additional surgical procedures and physical therapy to treat the loss of mobility caused by the large wound, the patient eventually made a full recovery.
The second patient discussed in the report, owned by the same client and treated by the same original veterinarian as the first dog, also had bloodroot injected into a benign tumor. A smaller amount of Neoplasene was used, and it appears that some of this leaked out after the injection. As a consequence of this, or perhaps of the variability in unregulated herbal products, the tissue reaction was not as severe as in the first patient. When the mass was surgically removed, an area of inflammation and tissue necrosis was observed near but not in the tumor. Luckily, this dog experienced minimal complications.
Clearly, complications can occur with any medication or treatment that has a measurable physiological effect. Anything that has no possibility of any side effects isn’t doing anything! And it is important to remember that anecdotes cannot be used to prove either the safety or the efficacy of a treatment. Anecdotes of benefit provide only enough evidence to justify more rigorous, systematic testing, not proof that a therapy works. In the majority of cases, such anecdotes turn out not to be accurate when more objective testing is done. Cases in which harm may have resulted from a treatment also cannot prove the treatment is unsafe. They do, however, provide reason to be cautious, and they raise the level of supportive evidence of benefit that should be expected prior to employing the treatment. Medicine is always about balancing the urgency of intervening in a patient’s condition with the available information about the risks and benefits of the intervention.
In the case of bloodroot, there is limited preclinical evidence to suggest it might be a useful treatment. It does kill cancer cells, but so does bleach, which is obviously not a good candidate for use as a medicine. The evidence that bloodroot kills cancer cells and spares healthy tissues is weak and contradicted by numerous cases of obvious tissue damage following application of the chemical. And there simply are no clinical studies to indicate a benefit in actual patients, much less a benefit greater than the potential risks. So we are left with anecdotes about bloodroot curing patients, which are of limited value as such anecdotes are often wrong for many reasons, and anecdotes of patients suffering severe, sometimes disfiguring or disabling injury after using it. Severe injury may not always happen, but it is an extreme risk to take when there is no real reason to expect the treatment has any benefit. Both of these patients would have been effectively cured, with much less suffering, injury, and expense for the owner, if they had been treated with conventional surgery rather than bloodroot.
Given the current state of the evidence, it is irresponsible of veterinarians to use bloodroot products on their patients. And in my opinion it is absolutely unethical for companies and individuals to profit from marketing these remedies without investing the resources in proper clinical studies to prove that they can be used safely and that they actually benefit patients. As I have discussed many times, herbal remedies are likely the most promising area of alternative medicine in which we will hopefully find effective medicines. But until they have been rigorously tested, and until they are regulated as stringently as pharmaceuticals, they are a dangerous gamble with our pets’ health and cannot reasonably be viewed as an alternative to established conventional treatments. Just as the pharmaceutical industry must be carefully watched to constrain the bad behavior that the profit motive can generate, so the herbal medicine industry cannot be trusted to provide trustworthy information and safe and effective remedies without much more oversight that it currently receives.
Posted in Herbs and Supplements
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Holistic Anesthesia for Dogs and Cats
In a bit of advertising on his blog, a prominent alternative veterinary medicine advocate recently discussed the case of a 15 year old dog that reportedly had heart disease and dental disease and had come to see this doctor because the client’s regular veterinarian felt the risk of anesthesia for dentistry outweighed the benefits in this patient. Few details are provided, but our hero claims to have determined that the heart condition did not require medication and could be managed with “natural therapies” (which likely means there was a heart murmur but no true heart disease, since there are no “natural” substitutes for real medication when there is real heart disease). The author then claims that he was able to successfully treat the dental disease with “holistic anesthesia,” which left the patient “acting like a puppy again.”
I am certainly a proponent of proper dental care, and I applaud the author for taking the position of mainstream veterinary medicine that proper dental care requires general anesthesia in our pets. This is a more controversial idea in alternative medicine circles than in the profession as a whole. And I certainly oppose the inappropriate use of potent heart medications, which sounds like it may have occurred in this case. However, the core message of this article seems to be that conventional doctors are inappropriately frightened by anesthesia in older pets and that such anesthesia can be done more safely if it is “holistic.” Having never heard the term “holistic anesthesia” before, I was curious what it might mean and whether there is any evidence that it is safer than conventional anesthetic practices.
As I have already discussed previously, “holistic” is one of those vacuous marketing terms that means whatever the speaker wants it to mean or nothing at all, like “natural” or “integrative.” I suspected the phrase “holistic anesthesia” simply meant ordinary anesthesia with some herbs, homeopathy, acupuncture, or other unproven or bogus methods added on and then falsely promoted as somehow safer than conventional anesthetic practices. And, that is pretty much what I found, though I was surprised that it is also sometimes used to refer to practices indistinguishable from conventional anesthetic methods.
The author of the heartwarming story about the old poodle advertises his “holistic” approach to anesthesia this way on his web site:
No More Anesthetic Worries
Surgery can be scary, and we know that you may be a bit nervous about anesthesia. That’s why your pet will receive a comprehensive physical examination prior to every surgery. Blood and urine tests will also be done when needed to minimize the risk associated with anesthesia. And to keep your pet’s chances of anesthetic complications to a minimum, we only use isoflurane gas. It’s a bit more expensive, but it’s the safest anesthetic available.Your pet is also monitored by a veterinary assistant and 3 monitoring machines which monitors: respiratory rate, heart rate, pulse oximetry and body temperature.
No surgery is routine at [We Make Stuff Up] Animal Hospital. You want the best for your pet, and so do we! And for those owners who are a bit nervous about anesthesia, or who wish to minimize anesthetic complications in their pets, we offer holistic anesthesia to allow for a safer procedure and quicker recovery time.
Wow! What a radical departure from conventional anesthetic practices! Who would have thought of doing a physical examination or laboratory tests before anesthesia, using the cutting edge isoflurane gas anesthetic, monitoring the patient under anesthesia, or treating each patient as a unique individual? Oh, wait…How about EVERYBODY!!! Ok, maybe not everybody, since there are undoubtedly some incompetent veterinarians in practice. But these practices are standard in conventional veterinary medicine and have been since I went to vet school over a decade ago. To advertise them as if they were somehow superior, “holistic” practices is deceitful rubbish, purely marketing driven. Is this really all there is to “holistic anesthesia?” Well, there might be a bit more to it.
The rich mine of nonsense that is the American Holistic Veterinary Medical Association (AHVMA) web site provides two articles from the AHVMA “journal” that go into a bit more detail.
Winter, W. Holistic anesthesia and surgery Part 1. Journal of the American Holistic Veterinary Medical Association 1999;18(2):33-36.
Winter, W. Holistic anesthesia and surgery Part 2. Journal of the American Holistic Veterinary Medical Association 1999;18(3):19-23.
The tone of these articles is unremittingly arrogant, self-aggrandizing, and hostile to conventional veterinary medicine, and the information provided is entirely opinion, with no effort to support any assertions with scientific evidence. For example:
When you need it, surgery is good. It is one of the two only good things going for allopaths. When used properly, modern equipment, drugs, and techniques are approaching the sacred, magical healing we see in Shamanism.
We holistic types get to use surgery too, but there are things we have to take into consideration if we want to claim it as a holistic modality (God, I love using the word “modality”). Sometimes it really is a pain to have a conscience. It is that weight we feel once we are “enlightened.”
Now, the article is twelve years old and written by a now-retired 1975 veterinary school graduate. So one can reasonably argue that it is not representative of what contemporary AHVMA members and other self-proclaimed “holistic” practitioners believe. However, it is the only published discussion of “holistic anesthesia” in the veterinary field, and it shares with the blog article mentioned above both the underlying tone and the absence of any reference to objective scientific evidence. Without some clearer definition of what is meant by “holistic anesthesia,” and without a specific repudiation on the part of the AHVMA and individual members, one might reasonably assume that the principles articulated here are still accepted by proponents of this purported special anesthetic approach.
The first claim Dr. Winter makes about “holistic” surgery and anesthesia is that many of the procedures conventional veterinarians perform are, or should be, unnecessary once the conditions that necessitate them are prevented or successfully treated with alternative methods. Prevention is certainly preferable to treatment of almost any disease, and contrary to the mythology and advertising of alternative medicine, this is an accepted principle in all veterinary medicine. Similarly, he goes on to claim that it is “holistic” to do the safest, least invasive procedure that will yield the desired outcome and that the cost of the procedure and overall condition of the patient should be considered. This is about as radical and unconventional line of thought as the advertising cited above, which is to say it is banal and universally accepted.
Dr. Winter then describes his preoperative routine. Interestingly, he specifically recommends avoiding alternative therapies before anesthetics, though not for the reason you might expect:
Rescue Remedy can be used preop but should be used sparingly as it may interfere with anesthesia. The same is definitely true of using Arnica pre-op. I never give it immediately before surgery. Since anesthetics are “toxic,” many of the good herbs, homeopathics, and flower essences are contraindicated. More anesthetic will be required and the animal will wake up too soon. Use these fine medicines later, after surgery.
Ah, so the “good” natural remedies interfere with the “toxic” anesthetics, so a holistic anesthetic approach should begin with only the same poisons conventional veterinarians employ for anesthesia. Hmm…
He then goes on with some more radical and counterculture notions such as reading the patient’s record and studying the specific procedure before performing it, referring cases beyond one’s expertise to specialists, trying to avoid interrupting surgical procedures, and so on. All revelations to most veterinary surgeons, no doubt. However, Dr. Winter does introduce a few concepts I will admit to not having been taught in vet school:
Surgeries also should be done in the morning to catch the best biorhythms… The holistic surgeon is always aware of moods, the overall feeling of the day, and whether it is a “good surgery day” or a “bad surgery day.” If the feeling of the staff, room or schedule feels off, it is much better to take a break, regroup, and reconsider the pace. In the worst case scenario, stop for the day and reschedule.
Good and true holistic clients will totally understand and even be grateful. I have also learned to read the body language and the words of each client as they bring in their animal for surgery. If you perceive any negativity, especially hostility or an ominous premonition, sit right down with them and talk about alternatives. Don’t cut on an animal if the owner is against you; it is very powerful and should be honored.
I have learned to benefit from cleansing the surgical rooms psychically and spiritually using smudges, candles, herbs, and other processes.
I will admit, it hasn’t occurred to me to cancel surgery if the staff or owner happen to be in a bad mood or to cleanse the surgical room psychically with incense to improve the safety of anesthetic and surgical procedures. Something to think about.
The bulk of the discussion of anesthesia per se emphasizes the use of injectable anesthetics and avoiding gas anesthetics, which he describes as “part of an expensive racket.” He also emphasizes speed above all other considerations in reducing surgical and anesthetic risks. These are opinions, mostly without scientific justification, that say more about the era in which the author was trained than about anything uniquely “holistic,” and I suspect they are not widely held by contemporary alternative practitioners. The same is likely true for the outdated sterile technique advice, the belief that pain should be largely left untreated because it forces the patient to “rest” and thus aids healing, and much of the other “Common Man technology” and techniques Dr. Winter recommends. However, what is common to these articles and the writing of younger advocates of “holistic” medicine is the blithe reliance on individual opinion and experience as a justification for pronouncements about what is or is not safe and effective care, the lack of interest in scientific evidence, and the continual derogation of conventional veterinary medicine.
Of course, in order to make so-called “holistic anesthesia” detectably different from conventional anesthesia, it is necessary to add a variety of unproven therapies to the usual treatment, and Dr. Winter certainly does this. Needless to say, he provides no evidence whatsoever to justify these practices:
I augment the natural raw diet, which we have discussed in other articles or which can be found in Dr. Pitcairn’s book, with extra chopped greens every day and bits of raw liver, 1-5 raw eggs (with shell)/ week helps too. For minerals I use Vitamineral Mix (see Pitcairn) varying from 1/2 teaspoon to several tablespoons daily and especially sea kelp, 1/8-1/2 teaspoon daily. I add Vitamin C, 1000mg/day for a cat and up to three times that amount for a large dog, and Vitamin E, 400 iu/week for a cat amd up to 400 iu/day for a large dog. My personal favorite herb for bone healing is Comfrey and I usually use dried herb added to the food. Herb books list many other bone setting herbs that will work as well. Continue all supplements for several months after healing. This diet and supplement regimen should be used in all trauma cases regardless of type of fixation. I also add specific homeopathics, flower essences, sometimes acupuncture, and sometimes magnets, depending upon the case…
Herbal medicine is at its zenith when it comes to wound dressing. Who has not applied Aloe Vera to a wound? It is satisfying, it soothes, the client loves it (usually), and it works. I have a veterinary book, out of print now, by Richard Holliday, DVM, which shows hundreds of pictures of wounds allowed to heal open, naturally with some debridement and with Aloe Vera. I have used the book and its pictures many times to convince an owner that natural healing will really work.
After all, who needs clinical research when you have pictures to prove something works?
Finally, Dr. Winter provides some marvelous examples of cognitive dissonance and the misunderstood, even persecuted attitude that often characterizes the writing of those promoting approaches widely believed to be nonsense. Like so much else in these articles, of course, this is not uniquely “holistic,” but it does reveal the nature of a perspective completely immune to evidence or any possibility that the author might be mistaken.
In closing, there is a problem with all that I have just said, and it applies equally to all holistic services. That is when things do not work out in a rapid, linear, positive manner with full healing. It will not take long for some owners (or did they all come to me and me alone?) to go to another non-holistic vet who will assure them that had they chosen any other option than the one you did, the animal would have healed perfectly! I call this Double Jeopardy, because you can be a loser either way. If you are afraid to try natural healing, you lose because you can never be brave enough to be holistic, but if you try it, and for whatever reason (almost always due to bad owner post-op care, not you) there is a problem, you will be the scum of the universe. You have to follow your heart here. Holistic medicine is not for the cowardly and the weak…
Other vets are very threatened by this simple healing style, primarily because they have never tried it and they may truly think you are crazy. I know from firsthand experience that they will often report you to State Boards for being incompetent if they get involved with a case you are healing this way, so be careful. Stitching or bandaging some wounds strictly for legal reasons could be considered holistic too. We live in a crazy world.
So if it doesn’t get better, it’s not your fault it’s probably the owner’s. But other veterinarians are likely to blame the bad outcome on your idiosyncratic and unconventional techniques (while, of course, holistic veterinarians would never claim that bad outcomes are the result of conventional medical practices and that they could have been avoided if the owner had followed a superior holistic technique). Other vets only object, of course, because they don’t understand, they haven’t tried your methods themselves, or they are “threatened.” So you have to follow your heart regardless of the apparent outcome of the evidence, though if legally threatened it can be “holistic” to do something incompatible with what you really believe is the best care.
Bottome Line
“Holistic anesthesia” is a meaningless, “feel-good” marketing term. In many cases, it is simply a rebranding of conventional anesthetic and surgical practices. In others, it is the addition of bogus or unproven alternative therapies to conventional care, with the credit for good results always going to the alternative methods and the blame for bad results always attributed to the conventional drugs or procedures. The use of the term, however, is a warning sign of a philosophical approach fundamentally hostile to science and scientific evidence and willing to alternative approaches by means of denigrating conventional medicine regardless of the lack of evidence to support claims of superior safety and efficacy.
Posted in General, Miscellaneous CAVM
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Placebo Treatment for Asthma: Works for the Mind but not the Lungs
Note: I originally wrote this for Science-Based Medicine, but Dr. David Gorski has posted a far more detailed review of the study, which I encourage everyone to read, so I am just posting my thoughts on the subject here.
The placebo effect is a controversial, and in my opinion deeply misunderstood, phenomenon. At Science-Based Medicine, there has been plenty of discussion and debate on the subject before, and different authors have slightly different perspectives (for example, Drs. Novella, Gorski,Ramey and pharmacist Scott Gavura). A recent study in the New England Journal of Medicine (NEJM) serves to illustrate nicely my own view of the nature of this phenomenon, so I thought I’d have a go at characterizing it.
The placebo effect is often claimed to be a real improvement in a patient’s disease that is caused by an inert treatment, purportedly through the power of the mind to heal the body when the patient believes they are receiving an effective therapy. This is certainly how alternative medicine advocates characterize it when scientific studies identify their interventions as no more effective than placebos. However, in my opinion this is not an accurate characterization of the placebo effect.
There are many non-specific treatment effects seen in clinical trials, including the placebo, and all create the perception and appearance of improvement in patients given a fake therapy which is actually doing nothing to alter the underlying medical condition causing the patients’ symptoms. Some such effects are artifacts of the research setting, like the Hawthorne Effect. In this phenomenon, people take better care of themselves when they are participating in a research study and being closely monitored, and so they tend to improve regardless of whether the treatment being studies is helping them or not.
Other non-specific treatment effects, like the placebo, are illusions created by the belief and expectations of the patient or investigators. They do not represent an unlocking of deep and powerful forces of mind over body. They simply trick us into feeling or looking better when our condition is really unchanged.
One can argue, of course, that if a patient perceives inherently subjective symptoms, such as pain or nausea, to be improved, then they must really be improved. There is some truth to this, but the argument can easily lead to exaggerating the benefits of fake treatments which don’t actually affect the patient’s physical health. Homeopathy may make a person experience his or her pain less intensely, but a real medicine will achieve this, usually to a greater extent than a placebo, by actually reducing the pain generated in the body as well as the perception of pain in the mind. Taking advantage of placebo affects that accompany all real medical treatments is fair enough, but substituting alternative therapies that are nothing but placebo for real medicine is not in the best interest of patients.
And this is doubly true for veterinary patients. Lacking beliefs and expectations about their health, my patients cannot experience the placebo effect per se. Some improvement in symptoms may occur as a result of conditioning and the human contact associated with therapy, but in general animals don’t enjoy the “benefit” of being fooled by their own minds into thinking an inert treatment has made them better. Unfortunately, animal owners and veterinarians are subject to being misled by non-specific treatment effects, and the “placebo-by-proxy” effect is quite potent. It creates an especially dangerous situation in which an animal’s caretakers believe they are helping the patient and the combination of cognitive errors and cognitive dissonance prevents them from appreciating that the animal’s condition is actually not improved.
The new NEJM paper demonstrates both how powerfully our own beliefs and expectations can fool us into feeling better and how careful we must be to distinguish this from actual improvement in our condition. The full article is behind a paywall, but a short summary is available.
Wechsler, ME. Kelley, JM. Ph.D. Boyd, IOE. Dutile,S. Marigowda, G. Kirsch, I. Israel, E. Kaptchuk, TJ. Active albuterol or placebo, sham acupuncture, or no intervention in asthma. N Engl J Med 2011; 365:119-126
Forty-six patients with asthma were randomly assigned to receive no treatment, or to treatment with an inhaled bronchodilator (albuterol, which opens up airways constricted by asthma), a placebo identical to the bronchodilator treatment, and sham acupuncture presented as “real” acupuncture (whatever that is). All patients were rotated through all the treatments and assessed after each, and the patients and investigators were blinded to the treatments insofar as possible. Obviously, patients and researchers could tell the difference between no treatment, an inhaler, and acupuncture. And as is always the case in studies of acupuncture, the acupuncturist undoubtedly knew that they weren’t providing what they would call genuine acupuncture treatment.
The patients were evaluated both in terms of their own perceptions of any improvement in their symptoms as well as an objective measure of their respiratory function. When given no treatment at all, patients reported an improvement in their symptoms of 21%. This likely represents a variety of non-specific treatment effects, such as the natural history of the disease, the aforementioned Hawthorne Effect, and so on. It also illustrates the value of a no-treatment group in clinical trials, when it is ethically possible to have one. This is an element of clinical trial design that sometimes gets inadequate attention in discussions of the pitfalls of medical research, though there is evidence that when such groups are included, the purportedly powerful effects of the placebo phenomenon become less impressive.
There was no difference in the improvement perceived by patients regardless of which of the other treatments they received. Between 45-50% improvement was reported after treatment with the albuterol inhaler, placebo inhaler, and sham acupuncture. So patients experienced nearly twice as much benefit from some treatment as from no treatment, but it made no difference whether the treatment was real or inert. This would seem to suggest that the placebo is a potent therapy and as good as a physiologically active medicine. After all, asthma symptoms are quite recognizable and uncomfortable, so it seems unlikely that such high rates of improvement would be only a function of the patients’ imagination. Perhaps there is something to this mind-body medicine idea, and alternative therapies really can make us better through placebo effects even if they don’t have any other effects?
Well, not so fast. In addition to asking the patients how they felt after each treatment, the investigators also measured their lung function, using an instrument that records, among other data, how much air the patients could force out of their lungs in a given period of time. It turns out that this objective measure showed a 20% improvement with the bronchodilator inhaler, but a significantly lower 7% improvement with the inert therapies or no treatment at all. So while the patients couldn’t tell the difference between real and fake therapies, their lungs certainly could.
This illustrates what I think is the key point to understand about the placebo effect: It can make us feel better without actually affecting our physical health. In any discussion of the placebo effect, we must bear this fact in mind. There is no magical power of mind over body involved. Placebo treatments affect our perceptions of our symptoms, but they do not improve our underlying medical condition.
It is a desirable and appropriate for doctors to make their patients feel better, but it is not enough to do so only in ways that leave the physical health of the patient fundamentally unchanged. We owe it to our patients to apply rigorous scientific methods to investigating our therapies and to developing interventions which actually treat the cause of the symptoms, not just the patients’ perceptions of them.
There is nothing wrong with taking advantage of placebo effects that inevitably accompany therapeutic interactions. But I believe it is unethical to employ therapies which are demonstrated to have only placebo effects, particularly when interventions that actually treat the underlying medical condition are available. And as a veterinarian, I am strongly opposed to using treatments that clearly work in humans only through belief and expectation, since these are very likely to mislead owners into believing the therapy is working without actually benefitting the patient.
This study illustrates both the power of the placebo effect to make us experience marked improvements in seemingly undeniable disease symptoms and also the powerlessness of the placebo effect to improve our physical health. It shows how easy it is for us to be fooled concerning the effectiveness of a medical therapy by our personal experiences as patients and doctors, as well as how easily a clinical study can generate the false impression of a beneficial therapeutic effect if placebo and no-treatment controls and objective outcome measures are not employed. Finally, it provides a point of evidence against the currently popular contention that even though some alternative therapies cannot be shown to have effects greater than placebo, they can be viewed as having real benefits by means of the placebo effect and the power of mind over body. At best, placebo effects can alter our perceptions of our symptoms to reduce our discomfort. But they cannot fundamentally improve our physical health, and there is real danger in believing they can if it leads us to rely on therapies that are only placebos.
Posted in General
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