Archive for: November, 2009

Science-based medicine: we are not automatons

Nov 21 2009 Published by under Medicine

Opponents of science-based medicine like to accuse the rest of us of failing to be "holisitc", of failing to see the whole individual who comes to us for health care. I've argued many times that this is not only wrong, but that so-called alternative docs, by recommending unproven treatments and giving false hope are actually harming their patients. The new USPSTF mammogram recommendations are likely to fuel this debate as well as the one regarding health care reform and rationing. There's already been a great deal of debate new mammogram recommendations, most of it good. For a comprehensive analysis of the topic, go and read Orac's take.

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16 responses so far

Why I won't be prescribing medical marijuana

Nov 19 2009 Published by under Medicine

In November, the citizens of my home state approved a medical marijuana law. The very next day, I started getting calls from patients (often not may own) asking how they could get it. I'm not fan of draconian laws that imprison people for getting stoned, but when it comes to medical interventions (rather than legal ones) I have an informed opinion. The new law allows Michigan residents to grow weed for their own consumption if they have approval. The law does not allow doctors to prescribe marijuana, rather it allows them to certify that the patient has a condition designated by statue as qualifying them for the medical marijuana program.
When I prescribe a pharmacologic intervention, I usually have some data to back up my decision. My most commonly prescribed medications, such as metformin, ACE inhibitors, beta blockers, statins, and aspirin, have clear dosing options and have clear outcome data that support their use. Marijuana is not a clearly science-based treatment.
That is not to say it isn't medically useful. There is a great deal of anecdotal data for its use in a variety of conditions, and there is scientific plausibility underlying this data. There are also data supporting the concept of cannabis dependence, and there is scientific plausibility to support the idea that smoking anything is probably bad for you. In other words, the available clinical data do not give a doctor a clear way to evaluate the risk/benefit ratio of pot.
In some circumstances, the decision is a bit more clear. In hospice patients or other patients with end-stage diseases, there is probably little harm in using cannabis, although we don't have a lot of data here either.
With marijuana, we have a drug that is not standardized, and has no clear indications for which it has been well-studied. There is no other drug whose use I would recommend on such scant data. There may be considerable promise in cannabis and its derivatives, but until the government allows more study, I'm not writing it.

55 responses so far

"I'm not getting a flu shot because I never get the flu"

Nov 19 2009 Published by under Medicine

Basing medical practice on science helps us avoid the pitfalls of relying on our own reasoning and experience. If I want to start a patient on a new medicine, the individual characteristics of the patient are important (Is the drug meant for their condition? Will it interact with other drugs they are on? Are they allergic to it? Can they tolerate it?) but at least as important is how the drug performs when used on large numbers of people. This attenuates the large differences that can be seen among individuals, and allows us to predict how in general the drug will act.  

One of the metrics we can use is something called the "number needed to treat/harm" (NNT). This is a nice measure which is a bit more intuitive than other statistics. For example, in the recently released USPSTF recommendations on mammography, it was reported that nearly 2000 women in their 40s needed to be screened to avert one breast cancer death (the number in the 60's age group was in the 300s). Deciding what that means is a value judgement. Is it worth it to screen so many for each life saved? Is it worth the pain of chasing down abnormal finding that are ultimately found to be benign?

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17 responses so far

No shame: antivaccine ghouls defame the dead, and elevate the disgraced

Nov 18 2009 Published by under Absurd medical claims, Medicine, Vaccination inanity

There are a couple of quotes circulating widely claiming that major players in flu vaccine development are "denouncing" the vaccine.
From (shudder!) mercola.com:

"Dr. Anthony Morris, a distinguished virologist and former Chief Vaccine Office at the U.S. Federal Drug Administration (FDA), states that "There is no evidence that any influenza vaccine thus far developed is effective in preventing or mitigating any attack of influenza" and that "The producers of these vaccines know they are worthless, but they go on selling them anyway."

And:

And in November 2007, the UK newspaper The Scotsman, made public warnings by the inventor of the "flu jab," Dr. Graeme Laver.
Dr. Laver was a major Australian scientist involved in the invention of a flu vaccine, in addition to playing a leading scientific role in the discovery of anti-flu drugs. He went on record as saying the vaccine he helped to create was ineffective and [that] natural infection with the flu was safer. "I have never been impressed with its efficacy," said Dr. Laver."

Who are these guys?

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15 responses so far

Covering Alternative Medicine---Another perspective

Nov 18 2009 Published by under Medicine

In a piece written for health reporters, journalist Jane Allen gives some useful advice about covering alternative medicine, but there are some gaps that are are hard for a non-medical professional to recognize (and frankly, for many medical professionals as well). She quite rightly urges skepticism, but when looking into ideologic and muddled topic of alternative medicine, skepticism needs to be turned up to "11". A major complaint that doctors have about health coverage is not the objectivity, earnestness, or research abilities of the reporter but the lack of some of the fundamental knowledge of the subject.

"Alternative medicine" can mean many things and the National Centers for Complementary and Alternative Medicine (NCCAM) provides a good starting point.  Whan many skeptics have pointed out over the years however is that there really is no "alternative" to medicine; only that which is proven to work, and that which is not.  This is one of the bases for ethical medical practice.  Medicine is full of compelling stories---we physicians hear them every day. But, knowledge of what does and does not work cannot be based on a good story.  The histories we record each day help guide us in treating individuals using interventions tested on larger groups.  The randomized-controlled trial (RCT) is often seen as the "gold standard" for testing medical interventions, but there are a two primary limitations to this view.  First, not all interventions can be examined using an RCT due to ethical and technical concerns.  Second, an RCT is often blind to the idea of "plausibility".  This leaves us open to what Dr. Harriet Hall has termed "Tooth Fairy Science":  we can generate statistically significant data about the average price of an incisor, the average time between tooth loss and monetary gain, and other such factors, but none of these numbers tells us whether the Tooth Fairy in fact exists.

 

If in reporting on health the goal is to inform as well as tell a good story, an informed skepticism is necessary.  Supporters of alternative medicine are often gripped by a religious-like zeal and may be somewhat deficient in skepticism.  Doctors and scientists are trained to be skeptics (a training that ometimes wears off) and usually start from the premise of "I don't believe it, show me the data".  Ms. Allen's excellent article lays out some of the problems:

 

The task of sorting it all out becomes all the harder because evidence for health claims in non-traditional medicine often does not rise to the gold-standard -- randomized, controlled clinical trials (those in which participants are randomly assigned either to an experimental group or to a comparison group) published in major peer-reviewed journals.

 

"There isn't the same depth of research, and there never will be," says Hardy, medical director of the Simms/Mann-UCLA Center for Integrative Oncology, who has long studied herbs and dietary supplements and often recommends them to appropriate patients. She says safety margins for herbal remedies, especially those used for thousands of years, are better than for prescription drugs. "It's very uncommon that any herb with traditional knowledge behind it will be as toxic as a new drug."

 

Claims about alternative, complementary and integrative medicine often are built on anecdotal evidence. But that's not the same as demonstrating their effectiveness through rigorous science....

 

When she's trying to evaluate such claims of an alternative remedy's effectiveness, Hardy wants study authors or those making the claims to provide multiple cases of good responses. She also wants to see a rationale for the treatment that is either consistent with the principles of alternative medicine practices, such as traditional Chinese medicine, or explainable through principles of Western medicine.

 

This credulous claim by a supporter of alternative medicine deserves careful parsing.  There is no reason that any claim made by alternative medicine cannot be subjected to the same scrutiny as any other intervention.  In fact, it's done regularly.  An NCCAM-funded study of Saw Palmetto, for example, found insufficient evidence to recommend its use.  This wasn't a set of anecdotes but a randomized-controlled trial, just the sort of "gold standard" that Hardy claims "there never will be" in researching herbs.

 

Her next claim that "any herb with traditional knowledge behind it" is unlikely to be as toxic as a new drug" is a non sequitur. Safety is only one factor
to consider in evaluating an intervention---the other, of course, is efficacy.  Something with no physiologic effects at all will not be toxic, by definition.  Something with significant physiologic effects can always have potential toxicities.  Another way of framing it is that there is no such thing as "side effects"---only effects, some desired, some not.

 

The final disturbing point made by Hardy is that claims should be evaluated via anecdotes that are seen through the lense of alternative medicine principles.  This is a terrible idea.  The evaluation of a medical intervention must rest on its safety and efficacy and its scientific plausibility. Calling something "alternative" does not render it immune from scientific investigation.

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52 responses so far

Another way to find swine flu shots

Nov 16 2009 Published by under Medicine

Hat tip to the incomparable, contentious, pain-in-the-ass-who-we-are-all-better-for-having-around scienceblogs regular becca for pointing out this site (from google of course) that helps locate flu shots in your area (in my area, everyone is "temporarily out of stock"). While you're visiting, check out google's flu trends as well.

10 responses so far

The "R" word: why we shouldn't fear health care rationing

Nov 14 2009 Published by under Health care reform, Medicine

An easy way to kill a debate on health care policy is to use the "R" word. We saw this early in the HCR debate with overheated talk of "death panels" and other nonsense. But we ignore the real issue of rationing at our own peril. Those of us who favor real HCR must embrace rationing, coopt it, show our opponents how it is inevitable.
Nowhere is the the Right more hypocritical than the issue of health care rationing (OK, maybe with sex stuff, but...). Everyone who studies American health care knows that we already ration; we just do it irrationally. Current rationing allocates resources to the wealthy and those with good jobs, and when we do care for the uninsured, unevenly spreads that cost to some hospitals and taxpayers. Medical services are reimbursed in an unstable fashion, with some services reimbursed well one year, and poorly the next, making planning nearly impossible for doctors, hospitals, and patients. For example, there are currently large cuts planned for some cardiology services, cuts which I don't disagree with in theory but cardiologists cannot provide good service to their patients if one year they are encouraged to go out and buy lots of fancy equipment and the next year are told they can't use it.
Hospitals struggle from year to year as economic downturns change the payor mix driving down income. There is no stability in our current system. It is not robust, for providers or for patients.

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33 responses so far

Mumps redux

Nov 13 2009 Published by under Medicine

The resurgence of vaccine-preventable diseases is a fascinating, if unwanted, phenomenon. Pertussis, measles, and now mumps are cropping up after long periods of quiescence. Mumps has been generally very well-controlled since the adoption of wide-spread vaccination, with no nation-wide outbreaks, but there have been a number of regional outbreaks, most notably in 2006 and now again in 2009. Since the widespread use of two-dose vaccines, mumps cases in the US have dropped by more than 99%.

In an analysis of the 2006 outbreak the authors noted a three year periodicity to wide-spread mumps epidemics,and predicted a 2009 outbreak similar to the 2006 outbreak based on pre-outbreak epidemiology..  It appears they were right. The CDC is reporting a sudden outbreak among a religious community in the Northeast (they don't say it explicitly but it appears to be an Orthodox Jewish community). The disease appears to have been imported from an ongoing UK outbreak, and then to have spread through the close quarters of a summer camp. As children returned home from camp, the disease spread through their communities.

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12 responses so far

Doctors are just like military dictators

Nov 12 2009 Published by under Absurd medical claims, Medicine

There's a number of dangers in carrying an analogy too far. One situation may be analogous to another without being identical, or they may not in fact be analogous at all. Forgetting this principle can get you into a wee bit of trouble.
To formalize it a bit, just because you think "A" resembles "B", and "B" has property "P" does not mean that "A" also has property "P". It may be that "A" is not quite enough like "B" to share all of its properties.
But a weak analogy can't stop a weak but persistent mind. Dana Ullman, Hahnemann's cognitively-impaired bulldog, has given us a fantastically weak analogy with which he tries to delegitimize all of modern medicine (to be replaced by...what? That is his second logical fallacy: if "A" is bad, that does not mean "B" is better, a sort of non sequitur in which he asserts that modern medicine is bad and therefore magic is better).
Rather than drag you through a complete fisking of the piece, I'll lay it out for you: doctors live by a military model in which arbitrarily-defined "enemies" (diseases) are blasted indiscriminately causing grave collateral damage. He goes on to explain how dissenters are quashed by being labelled as (gasp!) "unscientific".
Some of his brilliant flashes of insight include this:

Doctors may even be able to go the next step and surgically remove a symptom or an obstructive agent, but the assumption that removing a single symptom or pathological agent will create health is both simplistic and incorrect.

In other words, removing an inflamed appendix doesn't create total health and is therefore irrelevant---this one's a "Nirvana fallacy": because medicine isn't perfect, it is therefore wrong in its entirety.

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20 responses so far

"I am the great and powerful Oz PAL!"

Nov 11 2009 Published by under Medicine

In medicine, theater can go a long way. The seemingly simple acts of laying hands on a patient, leaning in to listen to them, and giving them instructions to follow can be therapeutic. Sometimes this is labelled as part of the so-called placebo effect, but whatever we call it, physicians (and priests) have been doing it for thousands of years. But how far should we push it? As medicine becomes more science-based, relying on actual evidence to guide practice, where does theater fit in?

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34 responses so far

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