“Conversation about the weather is the last refuge of the unimaginative.” – Oscar Wilde
I will state my bias up front. I am convinced by the preponderance of data in favor of man made global warming. At the most simplistic level, I can’t see how converting humongous tons of fossil fuel into CO2 and dumping it into the the atmosphere cannot have effects on the climate. To my mind its like determining vaccine efficacy or evolution. Plausible mechanism(s), good basic science, multiple studies using different lines of evidence that all come to the same conclusion. There are lots of fine points and nuances to be worked out, but the basic truth is reasonable and well defined. Infectious diseases lend some validation to the concept that the world is warming, since with global warming comes a variety of infectious diseases.
It is one big IF:THEN statement. IF global warming, THEN infections. Of course if the IF is not true, then the THEN doesn’t follow.
The House of Commons Science and Technology Committee (STC) has released a report, Evidence Check 2: Homeopathy, in which they recommend that the NHS stop funding homeopathy. The report is a rare commodity – a thoroughly science-based political document.
The committee went beyond simply stating that homeopathy does not work, and revealed impressive insight into the ethical, practical, and scientific problems caused by NHS support for an implausible and ineffective pseudoscience.
The STC formed in October of 2009, and this is their second report. The goals of the STC itself are significant step forward:
The purpose of Evidence Check is to examine how the Government uses evidence to formulate and review its policies.
We certainly can use more of that.
When I first heard that a retrovirus had been identified as a possible cause of chronic fatigue syndrome, I withheld judgment and awaited further developments. When I heard that two subsequent studies had failed to replicate the findings of the first, I assumed that the first had been a false alarm and would be disregarded. Not so.
It’s a classic case of wishful thinking outweighing good judgment. One unconfirmed report of an association between the XMRV virus and chronic fatigue syndrome (CFS) resulted in a rush to test for the virus, speculation about possible implications, and even suggestions for treatment. And the subsequent negative studies did little or nothing to reverse the trend.
XMRV is Xenotropic murine leukemia virus-related virus. In the past, there were reports that this retrovirus was associated with prostate cancer, but then other reports found no link. In 2009 a study was published in Science, “Detection of an Infectious Retrovirus, XMRV, in Blood Cells of Patients with Chronic Fatigue Syndrome” by Lombardi et al., reporting an association with CFS:
we identified DNA from a human gammaretrovirus, xenotropic murine leukemia virus–related virus (XMRV), in 68 of 101 patients (67%) as compared to 8 of 218 (3.7%) healthy controls. (more…)
This week on Science-Based Medicine I wrote an article about a new study looking at the onset of autism symptoms, showing that most children who will later be diagnosed with autism will show clear signs of autism at 12 months of age, but not 6 months. This is an interesting study that sheds light on the natural course of autism. I also discussed the implications of this study for the claim that autism is caused by vaccines.
Unfortunately, I made a statement that is simply wrong. I wrote:
Many children are diagnosed between the age of 2 and 3, during the height of the childhood vaccine schedule.
First, this was a vague statement – not quantitative, and was sloppily written, giving a different impression from the one I intended. I make these kinds of errors from time to time – that is one of the perils of daily blogging about technical topics, and posting blogs without editorial or peer-review. Most blog readers understand this, and typically I will simply clarify my prose or correct mistakes when they are pointed out.
However, since I often write about topics that interest dedicated ideologues who seek to sow anti-science and confusion, sometimes these errors open the door for the flame warriors. That is what happened in this case.
There once was a time when all food was organic and no pesticides were used. Health problems were treated with folk wisdom and natural remedies. There was no obesity, and people got lots of exercise. And in that time gone by, the average life expectancy was … 35!
That’s right. For most of human existence, according to fossil and anthropological data, the average human life expectancy was 35 years. As recently as 1900, American average life expectancy was only 48. Today, advocates of alternative health bemoan the current state of American health, the increasing numbers of obese people, the lack of exercise, the use of medications, the medicalization of childbirth. Yet life expectancy has never been longer, currently 77.7 years in the US.
Advocates of alternative health have a romanticized and completely unrealistic notion of purported benefits of a “natural” lifestyle. Far from being a paradise, it was hell. The difference between an average lifespan of 48 and one of 77.7 can be accounted for by modern medicine and increased agricultural production brought about by industrial farming methods (including pesticides). Nothing fundamental has changed about human beings. They are still prey to the same illnesses and accidents, but now they can be effectively treated. Indeed, some diseases can be completely prevented by vaccination.
So why are advocates of alternative health complaining? They are complaining because they long for an imagined past that literally never existed. In that sense, alternative health represents a form of fundamentalism. Obviously, fundamentalism is about religion and the analogy can only go so far, but there are several important characteristics of religious fundamentalism that are shared by alternative health advocacy. These include:
Understanding the natural history of a disease is an important framework to have. It not only is critical for prognosis, but also informs us about diagnostic and screening strategies, is important to assessing interventions, and provides clues to causation.
There has been much debate about the early course of autism, specifically the earliest age at which autism may be detected. At present scientific evidence suggests that autism is dominantly genetic, and so researchers expect that there may be early signs of autism even in infancy. Traditionally, however, autism is not diagnosed until age 2-3, when parents bring their children to medical attention, or when signs are detected on routine well-child visits or in day-care.
Retrospective studies, largely involving review of home movies, have suggested that autism can be diagnosed as early as 6-12 months, suggesting that parental report is not an adequate screen because subtle signs are hard to detect without rigorous observation.
Why is my mind so clean and pure? Because I am always changing it.
In medical school the old saying is that half of everything you learn will not be true in 10 years, the problem being they do not tell which half.
In medicine, the approach is, one hopes, that data leads to an opinion. You have to be careful not to let opinion guide how you evaluate the data. It is difficult to do, and I tell myself that my ego is not invested my interpretation of the data. I am not wrong, I am giving the best interpretation I can at the time. For years I yammered on about how it made no sense to give a beta-lactam and a quinolone for sepsis until a retrospective study suggested benefit of the combination. Bummer. Now when I talk to the housestaff about sepsis, I have to add a caveat about combination therapy. It is why my motto is, only half jokingly, “Frequently in error, never in doubt”.
At what point do you start to change you mind? Alter your message as a teacher? Have new behavior? Medicine is not all or nothing, black and white. Changes are incremental, and opinions change slowly, especially if results of a new study contradict commonly held conclusions from prior investigations.
Nevertheless, I am in the process of changing my mind, and it hurts. I feel like Mr. Gumby.
I get a lot of email asking me about various alternative therapies and supplements. A recurring theme on this blog has been the hyperbolic claims of alternative practitioners and supplement makers, and while I can’t answer every email, I can at least address some of them in the blog. Supplements are often marketed using unsupported health claims to which is appended the Quack Miranda Warning, essentially allowing the makers to say that the pill will have such and such a benefit, while simultaneously denying any responsibility for the claim. Since the FDA isn’t examining these claims, it’s worth while to ask our own questions.
The latest email concerned a product called CardioFuel. Let’s take a closer look at this stuff.
According to the distributor:
CardioFuel is the most profound energy producing supplement on the market today! It does something like no other can: Increase energy at the most basic metabolic level, by increasing ATP (the biochemical energy unit of transfer) production. More ATP means more energy reserves to overcome chronic disease, beat the competition, and handle the everyday stressors of today’s fast paced world!
So to be taken seriously, there should be evidence that this product: 1) increases ATP, 2) increases “energy reserves”, and 3) helps overcome chronic disease and “the competition”. First, it is not possible to directly measure ATP in a human being under normal clinical conditions, so any claims about this must be an inference from markers of ATP metabolism, or a guess. We’ll see what the literature says about this below. Second, we need an operational definition of “energy reserves”. Does this mean fat stores? Glycogen stores? These things are measurable to an extent. Finally, we can do a literature search to see if CardioFuel or an acceptable analog has been tested for its effect on relevant outcomes.
Last week I wrote about a study that purported to show that antidepressants have no effect in mild to moderate depression. A careful reading of the paper shows that the authors dramatically overstated their findings, particularly in their public statements to the media. The study has another implication beyond the misleading claims about antidepressants. It is an object lesson in an ongoing and disturbing phenomenon in mainstream journalism, the wholesale reprinting of press releases of scientific papers instead of reading and analyzing the papers themselves.
Pick up any newspaper or magazine and you can read about the latest scientific breakthroughs in cancer, Alzheimer’s or heart disease. Just keep in mind that what you are reading is probably a commercial message direct from the authors, not an accurate representation of the paper itself. Medical journalists are supposed to interpret the findings of recent medical publications and present them to the general public in ways that they can understand. They are supposed to provide context for the discovery, explaining what it might mean for disease treatment or cure. Yet, they rarely do. Instead, they simply copy the press release.
Most people are unaware that scientists issue press releases about their work and they are certainly unaware that medical journalists often copy them word for word. Instead of presenting an accurate representation of medical research, medical journalists have become complicit in transmitting inaccurate or deceptive “puff pieces” designed to hype the supposed discovery and hide any deficiencies in the research.
Imagine if a journalist reviewing the newest Ford cross-over vehicle didn’t bother to drive the car, but simply copied the Ford brochure word for word. Could you rely on the journalist’s evaluation? Of course not. Yet that is precisely what medical journalists are doing each and every day.
Surgeon and journalist, Atul Gawande, is getting quite a bit of deserved press and blog attention for his new book, The Checklist Manifesto: How to Get Things Right. The premise of his book is simple – checklists are an effective way to reduce error. But behind that simple message are some powerful ideas with significant implications for the culture of medicine.
One of the biggest ideas is that medicine has culture – a way of doing things and thinking about problems that subconsciously pervades the practice of medicine. This idea is not new to Gawande, but he puts it to powerful practice.
The Humble Checklist
Gawande tells not only the story of the checklist but of his personal experience designing and implementing a surgery checklist as part of a WHO project to reduce morbidity and mortality from surgery. He borrowed the idea from other industries, like aviation, that use checklists to operate complex machinery without forgetting to perform each little, but vitally important, step.