Tuesday, March 09, 2010

When MDs fail us

You'd think that doctors have had years of training and continually attend conferences and seminars such that they know which treatments/medications out there in the market work and which don't. Unfortunately, reality doesn't bear that out. Case in point: My 72-year old mom had experienced excruciating pain in the knee for about a month. When the pain failed to diminish after three days, she went to see an orthopedist who quickly  diagnosed her as having osteoarthritis of the knee and made out just one prescription: 1500mg of powdered glucosamine sulfate to be mixed with a glass of water and taken once a day. My mom dutifully followed the doctor's instructions and began taking the medication in the hopes that her torment will end.

Unfortunately her doctor had prescribed something that simply wouldn't work. You see, glucosamine sulfate has already been clinically tested, and the best studies to date show it does nothing for osteoarthritis. Back in 2007 when his Snake Oil Science: The Truth About Complementary Medicine was published, R. Barker Bausell said that the definitive study on glucosamine was one published in the New England Journal of Medicine in 2006. That study tested glucosamine, chondroitin, glucosamine with chondroitin, and celecoxib (an already tested and proven pain medication). The results? Except for celecoxib, all the others performed no better than placebo. In other words, glucosamine et al. were all ineffective.

Since 2006 several other studies have been done.

One 2007 study showed that glucosamine sulfate was better than placebo for knee osteoarthritis.  Another 2007 study showed that glucosamine HCl and chondroitin, with or without exercise, were no better than placebo for knee osteoarthritis. Sources like the Natural Medicines Comprehensive Database believe the evidence favors glucosamine sulfate but not glucosamine hydrochloride. A new study was published 19 February 2008 in the prestigious Annals of Internal Medicine.  It is arguably the best study to date, and may shed some light on the controversy. Carried out in the Netherlands in a primary care setting, it studied 222 patients with hip osteoarthritis over a 2 year period. Half the patients took glucosamine sulfate 1500 mg a day; half took a placebo. They concluded that glucosamine sulfate was no better than placebo in reducing symptoms and progression of hip osteoarthritis.

Thus, to date, the best studies show glucosamine to be mere placebo for osteoarthritis of this and that part of the body.

When there are conflicting studies such as in the glucosamine controversy, the better studies (better means bigger trial size, better designed, more stringent controls, stricter blinding, multicenter vs single center, etc.) are of course given more weight. But supposing all the studies are of equal quality and that they're all good studies. Then the mere fact that some show that X works and some conclude that X is no better than placebo, almost certainly means that the latter conclusion is correct. Why? Because, if X actually works and works significantly better than placebo then any good study will almost surely find a statistically significant difference between X and a placebo. That some good studies find it effective and some equally good ones conclude it isn't implies that the difference between X and the control is probably small. Thus, even if all the studies for glucosamine thus far are equally good studies--they're not--then it is more likely that further studies--better ones--will show X to be no better than a lactose pill.

And here's something to think about. Glucosamine is already present in our bodies, the amount of which is far far more than the recommnded dose:
[Dr.] Wallace Sampson, one of the other authors of this blog, has pointed out that the amount of glucosamine in the typical supplement dose is on the order of 1/1000th or 1/10,000th of the available glucosamine in the body, most of which is produced by the body itself. He says, “Glucosamine is not an essential nutrient like a vitamin or an essential amino acid, for which small amounts make a large difference. How much difference could that small additional amount make? If glucosamine or chondroitin worked, this would be a medical first and worthy of a Nobel. It probably cannot work.”

Hence, my mom's orthopedist had prescribed expensive crap. If the good doctor knows this then he was intentionally prescribing a placebo--hoping the placebo effect would kick in, leading to a reduction in the unbearable pain that mom was experiencing, and/or perhaps hoping that the pain would naturally subside and that she would attribute this to glucosamine. On the other hand, if this doctor actually thought that glucosamine is effective, then he's one hell of an ignorant "expert."

The sad thing is that another doctor--a general physician--whom she consulted thereafter most confidently backed up the glucosamine prescription, and went a step further and suggested glucosamine with MSM, saying in effect it's even better. A simple check on Quackwatch reveals that MSM stands for methylsufonylmethane, and that there are few studies involving MSM, and practically no clinical trials showing MSM as efficacious against any human disease. And so this doctor's recommendation is perhaps even worse, given that efficacy and safety studies on humans at the suggested dosage levels have not been carried out.

About two weeks pass and mom's burning pain does not subside. There are days when it feels less painful and days when it's hell. But overall there has been no improvement. So off she goes to see another doctor. After examining the patient and looking at the xray he ordered, this orthopedist tells her she doesn't have osteoarthritis at all. In fact her knee joint is in excellent condition. Instead she has a nerve problem.* And he prescribes an anti-neuropathic drug as well as two anti-inflammatory medications. But before mom leaves the clinic, the good doctor advises her to also look for an acupuncturist. He says that while he can't explain how it works, acupuncture can do wonders. For instance, he's heard of performing an appendectomy using only acupuncture as the anesthetic! And acupuncture has been around for thousands of years so there must be something to it.

To say that this is disappointing to hear is an understatement. The best studies on acupuncture--those that employ the most credible sham acupuncture procedure and have the best single/double blinding--show that "needling" at the, so to speak, magical points on the body is no better than poking needles anywhere else nor is it better than pretend pricks. And of course the traditional explanation for how acupuncture works is utter nonsense (where oh where could those dang meridians be and what exactly is the nature of and what instrument can measure the qi energy that's supposedly coursing through our bodies?). Needless to say, the doctor's argumentum ad antiquitatem is an elementary error in logic. And the story of doctors using acupuncture as the sole anesthetic invites the question, How true is it? As with anecdotes of cures the story is suspect. The devil is in the details you know. Even acupuncturists in China don't have magic needles.

My mother has been to five doctors in the last two months for this pain of hers. The above three have actually prescribed CAM treatments whose efficacy has been, for all practical purposes, scientifically refuted. It seems quite clear that at least two of the above doctors don't know this.

In a recent interview, Dr. Harriet Hall, aka SkepDoc, confirms that many doctors are now prescribing/suggesting alternative remedies to their patients (pertinent quote at 27:40 min of the podcast). The truth is, just because they have "MD" trailing behind their names doesn't mean that what comes out of their mouths is biblical and true and right. Doctors are fallible. They may not be cognizant of which treatment modalities are science and evidence-based. They can enthusiastically give their patients belief-based treatments (as Dr. Hall rightly calls it). They can misdiagnose and/or mis-treat.

It's bad enough when quacks peddle snake oil and nostrums. There are enough gullible, nonskeptical, uncritical people who fall for them daily and are even prepared to defend them (self-proclaimed panacea guru Eli Edwin Casimero just keeps coming to mind). But it's much worse when licensed doctors become knowing or unwitting hucksters themselves. Since doctors are legitimate experts on disease and their treatment we seldom or rarely question their pronouncements and the scribbles they hand over to us. We take their word for it that we are going to get better if we follow their instruction and pop this and that pill three times a day.. Thus, when our physicians start prescribing nostrum, there is a good chance that we'll end up believing these "alternative" treatments to be in fact effective remedies. The onus is, of course, on them. It is their ethical responsibility to know and make sure the treatments they offer their patients have been tested safe and effective. On the other hand, it is our lives we are placing in the hands of another human being. We owe it ourselves to make sure that this person isn't putting us in danger or giving us worthless treatments. So, caveat emptor. Be a smart patient. Be critically-minded. Be scientific. Read up and check the body of evidence.


* This highlights yet another problem that I pointed out yesterday--that misdiagnosis is not a rarity at all. My mother went through 4 doctors before the cause of her pain was finally correctly identified. Two of those doctors had completely opposing diagnoses.

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