It has long been recognized that there are substantial multifactorial placebo effects that create real and illusory improvements in response to even an inactive treatment. There is a tendency, however (especially in popular discussion), to oversimplify placebo effects – to treat them as one mind-over-matter effect for all outcomes. Meanwhile researchers are elucidating the many mechanisms that go into measured placebo effects, and the differing magnitude of placebo effects for different outcomes.
For example, placebo effects for pain appear to be maximal, while placebo effects for outcomes like cancer survival appear to be minimal.
A recent study sheds additional light on the expectation placebo effect for pain. The effect is, not surprisingly, substantial. However it does not extrapolate to placebo effects for outcomes other than pain, and the results of this very study give some indication why. From the abstract:
The effect of a fixed concentration of the μ-opioid agonist remifentanil on constant heat pain was assessed under three experimental conditions using a within-subject design: with no expectation of analgesia, with expectancy of a positive analgesic effect, and with negative expectancy of analgesia (that is, expectation of hyperalgesia or exacerbation of pain).
What they found was that the positive expectation group reported twice the analgesic effect as the no expectation group, and the negative expectation group reported no analgesic effect. This is a dramatic effect, but not surprising.
Last week David Gorski wrote a excellent post about why we have not yet cured cancer. It turns out, cancer is a category of many individual diseases that are very challenging to treat. We have made steady progress, and many people with cancer can now be cured – but we have not discovered the one cure for all cancer. I personally am not convinced that we will discover a single cure for all cancer, at least not with any extrapolation of current technology. But if we continue to make progress as we are cancer will become an increasingly treatable and even curable type of disease.
This topic also brings up a meme that has been around for a long time – the notion that scientists have already cured cancer but the cure is being suppressed by the powers that be, to protect cancer as a source of income. In the comments to David’s article, Zuvrick writes:
So we can find a cure. It has probably happened multiple times. But nobody wants to cure cancer. Too many researchers earn a living seeking a cure by remaining inside a narrow, restricted channel of dogma. Their institutions get grant money and survive from the funding. Big Pharma makes big bucks selling chemotherapy drugs, surgeons remove tumors and various radiation devices employ radiologists and firms making these machines. MRI and CT scans would not be needed for cancer if Rife technology were available today.
I have heard or read some version of this claim since before I entered medical school. Superficially it may sound like profound wisdom (cynicism is a cheap way to sound wise) – but the idea collapses under the slightest bit of logical scrutiny.
For the last week I have had a cold. I usually get one each winter. I have two kids in school and they bring home a lot of viruses. I also work in a hospital, which tends (for some reason) to have lots of sick people. Although this year I think I caught my cold while traveling. I’m almost over it now, but it’s certainly a miserable interlude to my normal routine.
One thing we can say for certain about the common cold – it’s common. It is therefore no surprise that there are lots of cold remedies, folk remedies, pharmaceuticals, and “alternative” treatments. Finding a “cure for the common cold” has also become a journalistic cliche – reporters will jump on any chance to claim that some new research may one day lead to a cure for the common cold. Just about any research into viruses, no matter how basic or preliminary, seems to get tagged with this headline. (It’s right up there with every fossil being a “missing link.”)
But despite the commonality of the cold, the overall success of modern medicine, and the many attempts to treat or prevent the cold – there are very few treatments that are actually of any benefit. The only certain treatment is tincture of time. Most colds will get better on their own in about a week. This also creates the impression that any treatment works – no matter what you do, your symptoms are likely to improve. It is also very common to get a mild cold that lasts just a day or so. Many people my feel a cold “coming on” but then it never manifests. This is likely because there was already some partial immunity, so the infection was wiped out quickly by the immune system. But this can also create the impression that whatever treatment was taken at the onset of symptoms worked really well, and even prevented the cold altogether.
Last year it was reported that there was a possible increase in narcolepsy, a sleep disorder characterized by excessive sleepiness, in children who had received the Pandemrix brand of H1N1 flu vaccine in Sweden, Finland, and Iceland. However a review of the data did not find a convincing connection, although concluded there was insufficient data at present and recommended further surveillance. A narcolepsy task force was formed in Finland, and now we have their preliminary report.
They conclude that the evidence suggests there is a connection:
Based on the preliminary analyses, the risk of falling ill with narcolepsy among those vaccinated in the 4-19 years age group was 9-fold in comparison to those unvaccinated in the same age group. This increase was most pronounced among those 5–15 years of age. No cases were observed among those under 4 years of age. Also, no increase in cases of narcolepsy or signs of vaccination impacting risk of falling ill with narcolepsy was observed among those above 19 years of age.
The World Health Organization (WHO) has reviewed these results and concluded:
WHO’s Global Advisory Committee on Vaccine Safety (GACVS) reviewed this data by telephone conference on 4 February 2011. GACVS agrees that further investigation is warranted concerning narcolepsy and vaccination against influenza (H1N1) 2009 with Pandemrix and other pandemic H1N1 vaccines. An increased risk of narcolepsy has not been observed in association with the use of any vaccines whether against influenza or other diseases in the past. Even at this stage, it does not appear that narcolepsy following vaccination against pandemic influenza is a general worldwide phenomenon and this complicates interpretation of the findings in Finland.
During my recent stint covering the Neuro ICU I noticed for the first time a checklist posted above each patient bed. The checklist covered the steps to undergo whenever performing an invasive procedure on the patient. I was glad to see that the checklist phenomenon had penetrated my hospital, although the implementation of safety checklists is far from complete.
A recent study published in the BMJ offers support for the efficacy of using checklists to reduce complications and improve patient outcomes. This is a retrospective study looking at mortality and length of stay in Michigan area ICUs, comparing those that had implemented the Michigan Keystone ICU project (including a safety checklist for the placement of central lines) with local ICUs that had not implemented the project. They found a 10% decrease in overall mortality, but the results were not significant for length of stay. Because this was a retrospective study it was not designed to prove cause and effect, but it is highly suggestive of the efficacy of implementing such checklists.
The checklist trend represents a culture change within medicine – and a good one. This change received its greatest boost with the publication of The Checklist Manifesto by Dr. Atul Gawande. He presents a compelling case for the need and efficacy of using checklists in order to minimize error.
A recent Cochrane review of the use of cholesterol-lowering statin drugs in primary prevention has sparked some controversy. The controversy is not so much over what the data says, but in what conclusions to draw from the data.
Statin drugs have been surrounded by controversy for a number of reasons. On the one hand they demonstrably lower cholesterol, and the evidence has shown that they also reduce the incidence of heart attacks and strokes. The data on whether or not they reduce mortality has been less clear, although this latest data actually supports that claim. However, statins have also been blockbuster drugs for pharmaceutical companies and this has spawned concerns (some might say paranoia) that drug companies are pushing billions of dollars worth of marginally effective drugs onto the public.
So are statins a savior or a scam? Life does not always provide nice clean answers to such simple dichotomies. The evidence clearly shows that statins work and are safe. However, pharmaceutical companies do like to present their data in the best light possible, and they need to be watched closely for this. The recent review does call them on some practices that might tend to exaggerate the utility of statins. Finally, the real question comes down to – where should we draw the line in terms of cost-benefit of a preventive measure like statins.
Let’s look as this recent review of the data to see what it actually shows.
At SBM we are highly in favor of physicians and scientists interfacing with the public, using mainstream and new media to promote the public understanding of science and to explain the modern practice of medicine. Now that Dr. Dean Edell has retired (unfortunately) from his radio show, it is probable that Dr. Mehmet Oz has the highest exposure of any media physician. I have never personally been a fan of Oz – a product of Oprah Winfrey, he has always mixed reasonable medical advice with promotion of dubious alternative health care. Harsh critics of Oz have charged him with selling out in order to promote his media career.
Regardless of his motivations, Oz has recently gone beyond coyly flirting with pseudoscience by directly promoting Joseph Mercola – a notorious internet doctor who himself promotes all sorts of pseudoscience and fear-mongering on his website. In an interview on his show, Dr. Oz praises Mercola while refraining from directly mentioning any of the more controversial positions that he takes. I will discuss the interview itself below, but first some background on Mercola.
Mercola is infamous among promoters of SBM for a number of reasons. First his website is highly monetized. While he frequently resorts to the “Big Pharma” conspiracy talk, he himself prints information on his site that supports the sales of supplements and other products. In my opinion this makes him a snake oil salesman, and everything he writes can no longer be considered objective medical advice but rather is advertising copy. I have no problem with monetizing websites to pay for bandwidth, as long as it’s within reason. But at some point you cross a fuzzy line where the website content is there to support sales, rather than the other way around – and Mercola is way past that line.
But far more importantly, the information on Mercola’s website is not science-based. Mercola frequently engages in rank fear-mongering – promoting every preliminary study that may suggest a possible connection as if it were a proven health risk.
The 1023 campaign is a UK based organization whose purpose is to raise awareness of the actual claims of homeopathy. The name is a reference to Avogadro’s number (6.02214179×10^23), which is the number of atoms or molecules of a substance in one unit called a mole. This is an important basic concept in chemistry, for it means that there are a finite number of bits of a substance in any solution, which further means that solutions cannot be infinitely diluted. You cannot have fractions of a molecule of any substance. There is therefore a dilutional limit – a point beyond which if you further dilute a solution you are increasingly likely to have removed all of the original substance.
Homeopathic preparations frequently use serial dilutions that vastly exceed this dilutional limit. This is a central fallacy of homeopathy (what homeopaths call a “law” of homeopathy). Samuel Hahnemann, who invented the fiction of homeopathy, knew about the dilutional limit but believed that substances gave their magical essence to water when diluted. Modern homeopaths believe this too, but in order to make their nonsense more marketable to a 21st century culture a tad more used to science (or at least scientific jargon) than Hahnemann’s, they have desperately tried to wrap “magical essence” in sciencey technobabble.
The 1023 campaign’s main purpose is public awareness. It appears that the best tool defenders of science-based medicine have against homeopathy is simply to make the public aware of what it actually is. I have not found any good surveys that quantify public beliefs on the subject (sounds like a good project) but it is my subjective experience (and that of many of my colleagues) from talking to countless patients and acquaintances that many if not most people are simply not aware of what homeopathy actually is. The term is often conflated with herbal or “natural” remedies. Shock and disbelief is a common reaction to explanations of what homeopaths actually claim.
It seems that for every established science there is an ideological group who is motivated to deny it. Denialism is a thriving pseudoscience and affects any issue with the slightest political or social implications. Sometimes, even easily verifiable facts can be denied, as people seem willing to make up their own facts as needed.
Denialists have an easy job – to spread doubt and confusion. It is far easier to muddy the waters with subtle distortions and logical fallacies than it is to set the record straight. Even when every bit of misinformation is countered, the general public is often left with the sense that the topic is controversial or uncertain. If denial is in line with a group’s ideology, then even the suggestion of doubt may be enough to reject solid science.
We see this when it comes to the effectiveness of vaccines, the evolution of life on earth, and anthropogenic global warming. A recent Pew poll shows that the campaign of global warming denial has been fairly successful – while the science becomes more solid around the consensus that the earth is warming and humans are contributing to this, the public is becoming less convinced.
A recent article in the journal Neurology reports the results of an observational study regarding the use of so-called complementary and alternative medicine (CAM) by patients with an incurable brain glioma. They found that 40% of patients sought some type of CAM treatment. These results are in line with prior surveys, but require closer inspection.
The study defined CAM as:
Complementary therapy was defined as methods or compounds not used in routine clinical practice and not scientifically evaluated.
This is a problematic definition, but reflects the fact that there is no universally accepted and clean definition of CAM. CAM is a hodge-podge of therapies and modalities that have only one thing in common – they have not met the science-based standard of care. It is not accurate to say that they are “not scientifically evaluated.” Some CAM therapies have not been evaluated, but many have, and have already been adequately found to lack efficacy. In the current study homeopathic remedies were the most commonly reported. Homeopathy has certainly been studied – and found to be indistinguishable from placebo.