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Why doctors usually cannot base decisions on science
Too many people believe medical decision-making is easy, and too many people believe it is based on science.
In reality, medicine is more like a Virginia pond in winter. Winters in Virginia generally allow some ice to form, but it is typically so thin that one would never walk on it, for fear of falling through.
Medicine is similar because physicians walk on a thin layer of science overlying a deep pool of ignorance. Even moderate weights will break through the science layer, dumping the physician underwater, trying not to flail.
A simple experiment shows that dunking your doctor is easy. Pretend you have an abnormal blood test and pretend you are taking a medication. Ask your doctor if the medication affects the blood test. The doctor will answer with some certainty, but if you ask, “Is the published evidence for that solid?” he will probably stammer. If you are taking a second medication and you ask him if the effect of the two medicines together has ever been studied in relation to the lab test, he will clench his jaw and stare daggers at you. Forget about three medications.
All physicians want solid, thick science under their feet, as a Minnesota pond would provide. But they’re in Virginia, where conditions simply don’t allow that: humans are so variable in their genetics and habits (and medications), that there is just no way to run experiments for all the permutations and combinations. This situation will worsen as genetic testing proliferates.
When applicable science is unavailable – the usual case – physicians must make decisions based on personal experience and on extrapolation from inapplicable science. This is called “clinical judgment.” It is incredibly demanding mindwork, and it is the reason we must have the smartest, most dedicated people in medicine – they are the ones who can learn to swim.
Gens Y, X, and Millennials can learn from the Boomers' health mistakes
The Baby Boomers are hopeless. Myself included. Their fundamental health trajectories became locked-in long ago. Anyone who has been smoking for 30 years, or ignoring their blood pressure for 30 years, or obese for 30 years, is going to pay a price.
Of course, “hopeless” is hyperbole: benefits from taming smoking, blood pressure, and weight accrue at any age. But medical technology lacks the ability to erase the accumulated effects of these insults to the arteries. That’s why prevention is the best medicine.
So let’s talk to Gens Y, X, and the Millennials, who are still young enough to avoid paying the piper. If I were king, everyone would spend six months working in a cardiac catheterization laboratory during their early 20s, watching one moth-eaten arterial system after another displayed on screens in depressing detail, and watching patient after patient pay the price for their bad decisions.
Actually, looking at arteriograms of the brain, like the one below, would be even more impactful. Not only do brain arteries seem a much deeper part of one’s being than heart arteries, but their startling (and beautiful) intricacy emphasizes how many things must work right to keep us healthy. Preserving that beauty is the best investment you can make.
Multi-system effects of cobalt-containing hip prostheses
To the Editor:
Allen et al (1) courageously report a woman who underwent heart transplantation when her cardiomyopathy’s reversible cause – arthroprosthetic cobaltism (APC) from bilateral metal-on-metal hips – went undiagnosed. Endorsing their conclusion that clinicians in cardiac, orthopedic, thyroid, rheumatic, and ophthalmic specialties need improved awareness of this multi-system disorder, we would add neurologists, psychiatrists, and, especially, primary care physicians.
Cobalt causes a full spectrum of neuropsychiatric effects, from anxiety and irritability to life- threatening mood and thought disorders, plus peripheral neuropathy, cranial neuropathy, cognitive decline, and gait disorders (2,3).
Primary care physicians are likely to encounter APC early in its course, when its manifestations – including tinnitus, fatigue, disturbed sleep, nausea, “mental fog,” and headaches – are mild, non-specific, and easily dismissed as simple aging (4,5).
However, because APC is both progressive and reversible, we suggest all physicians adopt a low threshold for checking cobalt levels in at-risk patients, even those without hip complaints and those with metal-on-plastic or metal-on-ceramic hips (3).
(1) Allen LA, Ambardekar AV, Devaraj KM, Maleszewski JJ, Wolfel EE. Missing elements of the history. N Engl J Med. 2014; 370: 559-566. PubMed 24499215
(2) Sotos JG, Tower SS. Systemic disease after hip replacement: aeromedical implications of arthroprosthetic cobaltism. Aviation, Space, and Environmental Medicine 2013; 84: 242-245.
(3) Catalani S, Rizzetti MC, Padovani A, Apostoli P. Neurotoxicity of cobalt. Hum Exp Toxicol. 2012; 31: 421-437.
(4) Tower SS. Arthroprosthetic cobaltism: neurological and cardiac manifestations in two patients with metal-on-metal arthroplasty: a case report. J Bone Joint Surg Am. 2010; 92: 2847-2851.
(5) Leikin JB, Karydes HC, Whiteley PM, Wills BK, Cumpston KL, Jacobs JJ. Outpatient toxicology clinic experience of patients with hip implants. Clin Toxicol (Phila). 2013; 51: 230-236.
For better or worse, vitamins are medicine, too
Vitamins have a good reputation. Many people think they can do only good, and never harm. Sadly, this is false.
Biologically, the only difference between a vitamin and a medication is that some amount of the vitamin is necessary for life. Once you go above that amount, however, it is better to think of vitamins as pharmaceuticals, endowed with the potential for both benefit and harm.
In short, despite their positive-sounding name, it is better to think of vitamin supplements as medications, with all their attendant risks.
For example, not many years ago, there was enormous enthusiasm for vitamin E’s potential to lower the risk of coronary artery disease, and many physicians began recommending vitamin E supplementation. Later research has shown no such benefit and, rather horrifyingly, has raised suspicions that vitamin E supplements increase the risk of heart failure. Even a vitamin having no known toxic effects at any dose, e.g. vitamin B12, can cause harm by obscuring the diagnosis of a disease.
Possibly excepting women who are contemplating or experiencing pregnancy, any decision about vitamin supplementation should be undertaken with the same deliberation used in recommending a pharmaceutical. Many supposedly healthy people (discussion of the term “healthy” is a topic unto itself) will indeed benefit from vitamin D or other supplements, but it is far safer to rephrase the question “Do you recommend vitamin supplements for healthy people?” as: “Do you recommend pharmaceutical medications for healthy people?”