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Archive for Diagnostic tests & procedures

The mammography wars heat up again (2012 edition)

One issue that keeps coming up time and time again for me is the issue of screening for cancer. Because I’m primarily a breast cancer surgeon in my clinical life, that means mammography, although many of the same issues come up time and time again in discussions of using prostate-specific antigen (PSA) screening for prostate cancer. Over time, my position regarding how to screen and when to screen has vacillated—er, um, evolved, yeah, that’s it—in response to new evidence, although the core, including my conclusion that women should definitely be screened beginning at age 50 and that it’s probably also a good idea to begin at age 40 but less frequently during that decade, has never changed. What does change is how strongly I feel about screening before 50.

My changes in emphasis and conclusions regarding screening mammography derive from my reading of the latest scientific and clinical evidence, but it’s more than just evidence that is in play here. Mammography, perhaps more than screening for any disease, is affected by more than just science. Policies regarding mammographic screening are also based on value judgments, politics, and awareness and advocacy campaigns going back decades. To some extent, this is true of many common diseases (i.e., that whether and how to screen for them are about more than just science), but in breast cancer arguably these issues are more intense. Add to that the seemingly eternal conflict between science and medicine communication, in which a simple message, repeated over and over, is required to get through, versus the messy science that tells us that the benefits of mammography are confounded by issues such as lead time and length bias that make it difficult indeed to tell if mammography—or any screening test for cancer, for that matter—saves lives and, if it does, how many. Part of the problem is that mammography tends to detect preferentially the very tumors that are less likely to be deadly, and it’s not surprising that periodically what I like to call the “mammography wars” heat up. This is not a new issue, but rather a controversy that flares up periodically. Usually this is a good thing.

And these wars just just heated up a little bit again late last week.
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Posted in: Cancer, Diagnostic tests & procedures, Politics and Regulation, Public Health

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Cancer care in the U.S. versus Europe: Is more necessarily better?

The U.S. is widely known to have the highest health care expenditures per capita in the world, and not just by a little, but by a lot. I’m not going to go into the reasons for this so much, other than to point out that how to rein in these costs has long been a flashpoint for debate. Indeed, most of the resistance to the Patient Protection and Affordable Care Act (PPACA), otherwise known in popular parlance as “Obamacare,” has been fueled by two things: (1) resistance to the mandate that everyone has to buy health insurance, and (2) the parts of the law designed to control the rise in health care costs. This later aspect of the PPACA has inspired cries of “Rationing!” and “Death panels!” Whenever science-based recommendations are made that suggest ways to decrease costs by reevaluating screening tests or decreasing various tests and interventions in situations where their use is not supported by scientific and clinical evidence, whether by the government or professional societies, you can count on it not being long before these cries go up, often from doctors themselves.

My perspective on this issue is that we already “ration” care. It’s just that government-controlled single payer plans and hybrid private-public universal health care plans use different criteria to ration care than our current system does. In the case of government-run health care systems, what will and will not be reimbursed is generally chosen based on evidence, politics, and cost, while in a system like the U.S. system what will and will not be reimbursed tends to be decided by insurance companies based on evidence leavened heavily with business considerations that involve appealing to the largest number of employers (who, let’s face it, are the primary customers of health insurance companies, not individuals insured by their health insurance plans). So what the debate is really about is, when boiled down to its essence, how to ration care and by how much, not whether care will be rationed. Ideally, how funding allocations are decided would be based on the best scientific evidence in a transparent fashion.

The study I’m about to discuss is anything but the best scientific evidence.
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Posted in: Cancer, Diagnostic tests & procedures, Politics and Regulation, Science and the Media

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Keeping the customer satisfied

One thing about blogging once a week or so compared to my other blogging gig, which is usually close to every day, occasionally more often, is that I really can’t cover everything I want to cover for this blog. Even more so than at my not-so-super-secret other blogging gig, I have to pass on topics that could be fodder for what could be excellent to even awesome posts—or, self-congratulating hyperbole aside, at least reasonably interesting to the readers of this blog. When that happens, I can only hope that one of my co-bloggers picks up on it and gives the subject matter the treatment it cries out for. Or, sometimes, such subject matter just has to be dealth with elsewhere by me—or not at all. Even a hypercaffeinated blogger like myself has limits.

Sometimes, however, I actually get a second chance. In other words, I get a chance to revisit a topic that I passed by. Usually, this happens when something new happens that gives me an excuse to revisit the topic. So it was last of week, when I was perusing the New York Times by an oncology nurse named Theresa Brown. Her article was titled, appropriately enough, Hospitals Aren’t Hotels. It will become very apparent very quickly why in a moment. But first, let’s sample Brown’s article a bit, because it brings up an issue that is very pertinent to science-based medicine:
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Posted in: Clinical Trials, Diagnostic tests & procedures, Epidemiology

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A surprising article about “integrative” medicine in The New England Journal of Medicine vs. “patient-centered” care

The New England Journal of Medicine (NEJM) is published on Thursdays. I mention this because this is one of the rare times where my owning Mondays on this blog tends to be a rather large advantage. Fridays are rotated between two or three different bloggers, and, as awesome as they are as writers, bloggers, and friends, they don’t possess the rabbit-like speed (and attention span) that I do that would allow me to see an article published in the NEJM on Thursday and get a post written about it by early Friday morning. This is, of course, a skill I have honed in my not-so-super-secret other blogging identity; so if I owned the Friday slot I could pull it off. However, the Monday slot is good enough because I’ll almost always have first crack at juicy studies and articles published in the NEJM before my fellow SBM partners in crime, unless Steve Novella managed to crank something out for his own personal blog on Friday, curse him.

My desire to be the firstest with the mostest when it comes to blogging about new articles notwithstanding, as I perused the table of contents of the NEJM this week, I was shocked to see an article that made me wonder whether the editors at NEJM might just be starting to “get it”—just a little bit—regarding “integrative” medicine. As our very own Mark Crislip put it a little more than a week ago:

If you integrate fantasy with reality, you do not instantiate reality. If you mix cow pie with apple pie, it does not make the cow pie taste better; it makes the apple pie worse.

Lately, though, I’ve been more fond of a version that doesn’t use fancy words like “instantiate”:

If you integrate fantasy with reality, you don’t make the fantasy more real. You temporarily make your reality seem more fantasy-based, but reality always wins out in the end.

The part about the cow pie needs no change, although I think ice cream works a bit better than apple pie. Your mileage may vary. Feel free to make up your own metaphor inspired by Mark’s.

In any case, in the Perspective section, I saw three articles about “patient-centered” care:
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Posted in: Cancer, Diagnostic tests & procedures, Medical Academia, Medical Ethics

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Is gluten the new Candida?

Much of the therapeutics I was taught as part of my pharmacy degree is now of historical interest only. New evidence emerges, and clinical practice change. New treatments replace old ones – sometimes because they’re demonstrably better, and sometimes because marketing trumps evidence. The same changes occurs in the over-the-counter section of the pharmacy, but it’s here marketing seems to completely dominate. There continues to be no lack of interest in vitamin supplements, despite a growing body of evidence that suggests either no benefit, or possible harm, with many products. Yet it’s the perception that these products are beneficial seem to be seem to continue to drive sales. Nowhere is this more apparent than in areas where it’s felt medical needs are not being met. I covered one aspect a few weeks ago in a post on IgG food intolerance blood tests which are clinically useless but sold widely. The diagnosis of celiac disease came up in the comments, which merits a more thorough discussion: particularly, the growing fears over gluten consumption. It reminds me of another dietary fad that seems to have peaked and faded: the fear of Candida.

It wasn’t until I left pharmacy school and started speaking with real patients that I learned we are all filled with Candida – yeast. Most chronic diseases could be traced back to candida, I was told. And it wasn’t just the customers who believed it. One particular pharmacy sold several different kits that purported to eliminate yeast in the body. But these didn’t contain antifungal drugs – most were combinations of laxative and purgatives, combined with psyllium and bentonite clay, all promising to sponge up toxins and candida and restore you to an Enhanced State of Wellness™. There was a strict diet to be followed, too: No sugar, no bread – anything it was thought the yeast would consume. While you can still find these kits for sale, the enthusiasm for them seems to have waned. Whether consumers have caught on that these kits are useless, or have abandoned them because they don’t actually treat any underlying medical issues, isn’t clear.

The trend (which admittedly is hard to quantify) seems to have shifted, now that there’s a new dietary orthodoxy to question. Yeast is out. The real enemy is gluten: consume it at your own risk. There’s a growing demand for gluten labeling, and food producers are bringing out an expanding array of gluten-free (GF) foods. This is fantastic news for those with celiac disease, an immune reaction to gluten, where total gluten avoidance is essential. Only in the past decade or so has the true prevalence of celiac disease has become clear: about 1 in 100 have the disease. With the more frequent diagnosis of celiac disease, the awareness of gluten, and the harm it can cause to some, has soared. But going gluten free isn’t just for those with celiac disease. Tennis star Novak Djokovic doesn’t have celiac disease, but went on a GF diet. Headlines like “Djokovic switched to gluten-free diet, now he’s unstoppable on court” followed. Among children, there’s the pervasive but unfounded linkage of gluten consumption with autism, popularized by Jenny McCarthy and others. Even in the absence of any undesirable symptoms, gluten is being perceived as something to be avoided. (more…)

Posted in: Basic Science, Diagnostic tests & procedures, Nutrition, Science and Medicine

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Re-thinking the Annual Physical

Please note: the following refers to routine physicals and screening tests in healthy, asymptomatic adults. It does not apply to people who have been diagnosed with diseases, who have any kind of symptoms or signs, or who are at particularly high risk of certain specific diseases.


Throughout most of human history, people have consulted doctors (or shamans or other supposed providers of medical care) only when they were sick.  Not too long ago, the “if it ain’t broke don’t fix it” mindset changed. It became customary for everyone to have a yearly checkup with a doctor even if they were feeling perfectly well. The doctor would look in your eyes, ears and mouth, listen to your heart and lungs with a stethoscope and poke and prod other parts of your anatomy. He would do several routine tests, perhaps a blood count, urinalysis, EKG, chest-x-ray and TB tine test. There was even an “executive physical” based on the concept that more is better if you can afford it. Perhaps the need for maintenance of cars had an influence: the annual physical was analogous to the 30,000 mile checkup on your vehicle. The assumption was that this process would find and fix any problems and insure that any disease process would be detected at an early stage where earlier treatment would improve final outcomes. It would keep your body running like a well-tuned engine and possibly save your life.

We have gradually come to realize that the routine physical did little or nothing to improve health outcomes and was largely a waste of time and money. Today the emphasis is on identifying factors that can be altered to improve outcomes. We are even seeing articles in the popular press telling the public that no medical group advises annual checkups for healthy adults. If patients see their doctor only when they have symptoms, the doctor can take advantage of those visits to update vaccinations and any indicated screening tests.

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Posted in: Diagnostic tests & procedures, Science and Medicine

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AK: Nonsense on Full Automatic

I start these entries about a week before their due date, and when I saw Dr Hall’s Applied Kinesiology (AK) post from Tuesday, I thought the heck, there goes my post for Friday.  After reading Harriet’s post, I think mine will be both complementary and alternative, and perhaps even integrative, to her entry.  I do have one quibble with her post. She said

“we skeptics don’t dismiss AK just because it sounds silly.”

AK doesn’t just sound silly, it is silly.  I have found over the years writing for SBM that I have developed an increasing bias around the concept of prior probability.  As best I can tell there is a well described reality, and that reality constrains what is not only probable, but what is possible.  Within the limitations of our current understanding of reality, some processes are impossible, i.e. have zero prior probability. AK’s prior probability is exactly zero.   I sometimes think the blog should be called Reality Based Medicine.  Science gives us understanding of reality and AK, like many a SCAM (Supplements, Complementary and Alternative Medicine) discussed in this blog, parted company with reality from the beginning.

This blog has two often overlapping purposes.  Blogs offer timely commentary on contemporary issues, and this blog certainly fills that role.  More than other blogs, SBM also has the opportunity to be a reference source on various SCAM’s .  I have had the recent opportunity to reread the entire oeuvre of SBM, and it is impressive in the breadth and depth of topics covered in its three plus years.  It is not yet encyclopedic and there are many topics not yet reviewed in the blog, such as Applied Kinesiology.  So many many SCAM’s, so little time. (more…)

Posted in: Chiropractic, Diagnostic tests & procedures, Energy Medicine, Science and Medicine

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IgG Food Intolerance Tests: What does the science say?

I spend a lot of time as a pharmacist discussing side effects and allergies to drugs. For your own safety, I won’t recommend or dispense a drug until I know your allergy status. I don’t limit the history to drugs—I want to know anything you’re allergic to, be it environmental, food, insects, or anything else. Allergies can create true therapeutic challenges: We can’t dismiss any allergy claim, but as I’ve blogged before, there’s a big gap between what many perceive as an allergy and what is clinically considered a true allergy. My concern is not only avoiding the harm of an allergic reaction, but also avoiding the potential consequences from selecting a suboptimal therapy that may in fact be appropriate. You may need a specific drug someday, so  I encourage patients to discuss vague drug allergies with their physician, and request allergist testing as required.

Food allergies can be as real as drug allergies, and are arguably much harder to prevent. We can usually control when we get penicillin. But what about peanuts, eggs, or milk, all of which can also cause life-threatening anaphylaxis?  Food allergies seems to be growing: not only anaphylaxis, but more people believe they have some sort of allergy to food.  Allergy is sometimes confused with the term “intolerance”, which seems more common, possibly as the availability of “food intolerance testing” grows. Food intolerance testing and screening is particularly popular among alternative practitioners. Testing can take different forms, but generally the consumer is screened against hundreds of food products and food additives. They are then provided with a list of foods they are “intolerant” to. I’ve spoken with consumers who are struggling to overhaul their diet, having been advised that they are actually intolerant to many of their favourite foods. These reports are taken seriously by patients who believe that they’ll feel better if they eliminate these products. In the pharmacy, I’ve been asked to verify the absence of trace amounts of different fillers in medications because of a perceived intolerance.  Children may be tested, too, and parents may be given a long list of foods they are told their child is intolerant of. I’ve seen the effects in the community, too. Think going “peanut free” is tough? A public school in my area sent home a list of forbidden food products: dairy, eggs, bananas, tree nuts, peanuts, soy, sesame, flax seed, kiwi, chicken, and bacon. Were these all true allergies? It’s not disclosed. Anaphylactic or not, the parents had informed the school, and the school had banned the food product.

But can a simple blood test actually identify and eliminate food intolerance? That’s the question I wanted to answer.

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Posted in: Basic Science, Diagnostic tests & procedures, Health Fraud, Herbs & Supplements, Naturopathy, Science and Medicine

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Blind-Spot Mapping, Cortical Function, and Chiropractic Manipulation

Steven Novella recently wrote about so-called “chiropractic neurology” and its most outspoken proponent, Ted Carrick.  In 2005 I published an article in The Scientific Review of Alternative Medicine (Vol 9, No 1, p. 11-15) entitled “Blind-Spot Mapping, Cortical Function, and Chiropractic Manipulation.” It was an analysis of a study Carrick had published.

Carrick read a shorter, popularized version of my critique in Skeptical Inquirer and responded with a diatribe that was inaccurate, distorted what I had said, and accused me of fraud, deception, and mis-representation.  He failed to offer a credible rebuttal of my specific criticisms; and, in my opinion, showed that he failed to understand some of my points. He referred to me as “Ms. Hall” and suggested that I was psychotic. He characterized my e-mail correspondence with him as “bizarre, rude, and offensive.” It was none of those, and I have copies of the e-mails to prove it. Carrick says he “forwarded it to the legal council for the American Chiropractic Association for review.”  Now that strikes me as bizarre.

I am re-publishing the entire text of my article here as an instructive example of what passes for science in the chiropractic neurology community. Readers can judge for themselves whether my critique amounts to fraud and whether I am showing signs of psychosis, whether Carrick is a good scientist and whether his reply to my critique was appropriate. (more…)

Posted in: Chiropractic, Diagnostic tests & procedures, Neuroscience/Mental Health, Ophthalmology

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Woo-omics

Every so often, I come across studies that leave me scratching my head. Sometimes, these studies are legitimate scientific studies that have huge flaws or come from an assumption that is very off-base. Other times, they involve what Harriet Hall has termed “tooth fairy science,” wherein the tools of science are used to study a phenomenon that is fantastical, whose very existence hasn’t been demonstrated. Many such studies, not surprisingly, are studies of “complementary and alternative medicine” (CAM) or “integrative medicine” (IM). Modalities like reiki (which is faith healing that substitutes Eastern mysticism for Christian beliefs) and homeopathy (which is, when you boil it down to its essence, sympathetic magic) fall into the category of therapeutic modalities that are based on fantasy but are studied as with the latest tools of science, producing no end to confusing noise. This “tooth fairy science” has, over the last few years, reached its epitome in the application of the latest genomics technology to, in essence, magic, and I’ve recently come across an incredible example of just such a thing. But, first, let’s take a step back to what is going on in medical science now before I introduce a concept that I’ve dubbed “woo-omics.”

A prelude to woo-omics: Genomics, proteomics, everywhere an “omics”

One of the most difficult problems in science-based medicine is how to do a better job identifying which patients will respond to which treatments. Clinical trials, by their very design, have to look at average responses in populations. In essence, a treatment is compared to either placebo or standard-of-care, a choice mainly driven by ethics and whether effective treatments exist for the condition being studied. It is then determined using statistics whether a significant difference exists between the two groups. The difficulty, as any clinician knows, is applying the results of clinical trials to individual patients. In any population, there is, after all, a range of responses to any drug or treatment, and it would be desirable to be able to predict which patients will fall at the end of the bell-shaped curve where the treatment is most effective and which will fall at the end of the curve where the treatment works poorly or not at all.
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Posted in: Basic Science, Diagnostic tests & procedures, Medical Academia, Science and Medicine

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