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Archive for Diagnostic tests & procedures

Point-of-Care Ultrasound: The Best Thing Since Stethoscopes?

A bit of good news for a change: a “Perspective” article in the New England Journal of Medicine describes how point-of-care ultrasound devices are being integrated into medical education. The wonders of modern medical technology are akin to science fiction. We don’t yet have a tricorder like “Bones” McCoy uses on Star Trek, but we are heading in that direction, and the new handheld ultrasound devices are a promising development.

The stethoscope has become iconic, a symbol of medical expertise draped proudly around the neck by doctors and other medical personnel. Before it was invented, doctors could only try to listen to a patient’s heart by direct application of ear to chest. In 1816, Laennec interposed a tube of rolled paper between ear and chest, and the stethoscope was born. It quickly became an essential tool, allowing us to hear the distinctive murmurs produced by different heart valve abnormalities, to take blood pressures, to detect the wheezing of asthma or the collapse of a lung , to hear the bruits caused by atherosclerotic narrowing of blood vessels, to detect intestinal obstructions by listening for borborygmi (I love that onomatopoeic word!).

The stethoscope allows us to hear sounds produced by the body, but sound also allows us to see inside the body. Diagnostic ultrasound has a multitude of uses. With prenatal sonograms, we can determine the sex of a fetus, watch it suck its thumb, and even take its picture for the family album. With echocardiography we can evaluate heart valves, see fluid accumulation in the pericardium, observe the thickness and motion of the heart wall, and even quantify the efficiency of the pumping process. Ultrasound lets us see clots in blood vessels and stones in the gallbladder, evaluate abdominal organs, detect cysts, screen for carotid artery narrowing and abdominal aortic aneurysms, and guide needles into the body for therapeutic and diagnostic purposes. (more…)

Posted in: Diagnostic tests & procedures, Medical Academia, Medical devices

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The Canadian National Breast Screening Study ignites a new round in the mammography wars

The last couple of weeks, I’ve made allusions to the “Bat Signal” (or, as I called it, the “Cancer Signal,” although that’s a horrible name and I need to think of a better one). Basically, when the Bat Cancer Signal goes up (hey, I like that one better, but do bats get cancer?), it means that a study or story has hit the press that demands my attention. It happened again just last week, when stories started hitting the press hot and heavy about a new study of mammography, stories with titles like Vast Study Casts Doubts on Value of Mammograms and Do Mammograms Save Lives? ‘Hardly,’ a New Study Finds, but I had a dilemma. The reason is that the stories about this new study hit the press largely last Tuesday and Wednesday, the study having apparently been released “in the wild” Monday night. People were e-mailing me and Tweeting at me the study and asking if I was going to blog it. Even Harriet Hall wanted to know if I was going to cover it. (And you know we all have a damned hard time denying such a request when Harriet makes it.) Even worse, the PR person at my cancer center was sending out frantic e-mails to breast cancer clinicians because the press had been calling her and wanted expert comment. Yikes!

What to do? What to do? My turn to blog here wasn’t for five more days, and, although I have in the past occasionally jumped my turn and posted on a day not my own, I hate to draw attention from one of our other fine bloggers unless it’s something really critical. Yet, in the blogosphere, stories like this have a short half-life. I could have written something up and posted it on my not-so-secret other blog (NSSOB, for you newbies), but I like to save studies like this to appear either first here or, at worst, concurrently with a crosspost at my NSSOB. (Guess what’s happening today?) So that’s what I ended up doing, and in a way I’m glad I did. The reason is that it gave me time to cogitate and wait for reactions. True, it’s at the risk of the study fading from the public consciousness, as it had already begun to do by Friday, but such is life.
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Posted in: Cancer, Clinical Trials, Diagnostic tests & procedures, Public Health

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An experiment in paying through the nose for “unnecessary care”

Rats. Harriet stole what was going to be the title of this post! This is going to be something completely different than what I usually write about. Well, maybe not completely different, but different from the vast majority of my posts. As Dr. Snyder noted on Friday, it’s easy to find new woo-filled claims or dangerous, evidence-lacking trends to write about. Heck, I did it just last week, much to the continued consternation of one of our regular readers and commenters. Examining certain other health-related issues from a science-based perspective is more difficult, but I feel obligated to do it from time to time, not just for a change of pace but to stimulate the synapses and educate myself—and, I hope, you as well—about areas outside of my usual expertise.

We spend a lot of time writing about the scientific basis of medicine, clinical trials, what is and isn’t quackery, and how “complementary and alternative medicine” (CAM) subverts the scientific basis of medicine. However, SBM goes far beyond just that. At least I think of it this way. That’s why I’ve looked at issues that go more to the heart of health policy, which should be based on sound science and evidence. That evidence might take different forms than it does for determining, for example, whether Medicaid results in better health outcomes and by how much health insurance does the same. As is the case with policy issues and economics, conclusions are muddled and messy. The error bars are huge, and the number of potential confounders even huger. (more…)

Posted in: Clinical Trials, Diagnostic tests & procedures, Politics and Regulation, Public Health

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“Low T”: The triumph of marketing over science

A man on TV is selling me a miracle cure that will keep me young forever. It’s called Androgel…for treating something called Low T, a pharmaceutical company–recognized condition affecting millions of men with low testosterone, previously known as getting older.

The Colbert Report, December 2012

 

And now for something completely different…sort of.

After writing so much about the latest developments in the ongoing saga of the cancer doctor who is not an oncologist and not a legitimate cancer researcher, plus a rumination on what’s up with President Obama’s nominee for Surgeon General and our favorite form of unscientific medicine, so-called complementary and alternative medicine (CAM), also known as “integrative medicine,” I thought it was time for a change of pace. I wasn’t sure what I was going to write about as Sunday rolled around, but fortunately, as sometimes happens, the New York Times dropped a topic right in my lap, so to speak, both figuratively and literally. It comes in the form of a long article on something that directly concerns men of a certain age, which unfortunately happens to mean men of my age and older. I’m referring to what pharmaceutical company advertising campaigns have dubbed “low T,” short for low testosterone. It’s not clear how the term “low T” originated but Dr. Abraham Morgentaler, founder of Men’s Health Boston, claims to have coined the term when his patients were embarrassed by their difficulty pronouncing the word “testosterone.” Other sources report that it was Solvay Pharmaceuticals that coined the phrase. It doesn’t really matter where the term “low T” came from. The term has stuck, even though the more “correct” medical term would be hypogonadism, as in a man’s testes not working.
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Posted in: Clinical Trials, Diagnostic tests & procedures, Pharmaceuticals, Science and the Media

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Colonoscopy and Other Colorectal Cancer Screening Options: An Update

When I wrote about colonoscopy in 2010, colonoscopy was thought to be the best screening test for colorectal cancer because it could visualize the entire colon and could remove adenomas that were precursors of cancer. But only fecal occult blood testing (FOBT) and sigmoidoscopy had been proven to decrease colorectal cancer incidence and mortality (by 16% and 28%, respectively). Observational evidence suggested that colonoscopy would reduce the incidence and the number of deaths from colorectal cancer, but there were no randomized controlled trials, and the reduction in incidence of cancer after colonoscopy screening seemed to be restricted to left-sided colon cancers, which didn’t make sense.

We still don’t have any randomized controlled trials of colonoscopy, but a 2013 case-control study from Germany compared patients with and without colorectal cancer and found that those who reported having had a colonoscopy were less likely to develop colon cancer for up to 10 years after the procedure. And now two studies published in the New England Journal of Medicine in September 2013 have shed more light on the subject.
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Posted in: Cancer, Diagnostic tests & procedures

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Redefining cancer

Blogging is a rather immediate endeavor. Over the last nine years (nearly), I’ve lost track of how many times I saw something that I wanted to blog about but by the time I got around to it, it was no longer topical. Usually what happens is that my Dug the Dog tendencies take over, as I’m distracted by yet another squirrel, although sometimes there are just too many targets topics and too little time. Fortunately, however, sometimes the issue is resurrected, sometimes in a really dumb way, such that I have an excuse to correct my previous oversight. This is just such a time, and the manner in which the topic has been resurrected is every bit as dumb as the rant by the Food Babe that Mark Crislip so delightfully deconstructed last Friday. Unfortunately, for purposes of snark, I’m not Mark Crislip—but, then, who is?—but fortunately I am known elsewhere (and sometimes here) for being a bit “insolent.” So let’s dig in. We’ll start with the idiocy and then use that as a “teachable moment” about cancer biology. Funny how I manage to do that sort of thing so often.

Abuse of cancer science for political purposes

I realize that we at SBM are supposed to stay, for the most part, apolitical, but the idiocy that’s leading me to revisit a topic is unavoidably political because it involves using a profound misunderstanding of science for political ends. Specifically, I’m referring to the misuse of a legitimate scientific debate about cancer screening and diagnosis for purely political ends. First, however, for those not living in the US or my fellow citizens who might be blissfully unaware (in this case) of recent events, during the first half of October, our nation underwent what can only be described as a self-inflicted crisis that could have caused worldwide economic turmoil if it hadn’t been (sort of) resolved at the last minute. The reason for the crisis boiled down to the extreme resistance of some of our more radically conservative Representatives to the Patient Protection and Affordable Care Act, usually referred to as just the Affordable Care Act (ACA) or, colloquially, Obamacare. Normally when we write about Obamacare here on SBM, it’s to complain about how advocates of unscientific medicine and outright quackery have tried to piggyback their advocacy on the ACA in order to have health insurance plans sold through government exchanges cover modalities like naturopathy, chiropractic, and other so-called “complementary and alternative medicine” (CAM) or “integrative medicine.” In related posts, I’ve examined the evidence with respect to the relationship between health insurance and mortality and whether attacks on Medicaid as not improving the health of patients insured by it have any validity. (Let’s just say they are oversimplifications and distortions.)
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Posted in: Cancer, Diagnostic tests & procedures, Politics and Regulation, Science and the Media

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Baby’s DNA in Mom’s Blood: Noninvasive Prenatal Testing

Until recently, the moment of birth was a surprise. We anxiously awaited the obstetrician’s announcement: “It’s a boy!” or “It’s a girl!” Then we checked to see if any crucial parts were missing and we counted the fingers and toes. We had to wait for a baby to be born before we could know its sex and whether it was normal. Today, thanks to prenatal testing, we can know the sex of a fetus, diagnose a number of genetic abnormalities and malformations, and we can even operate on the fetus in utero to correct certain problems before birth. I had amniocentesis for my two pregnancies because of the higher risk of Down syndrome at my age (37 and 39). It was reassuring to know the baby didn’t have Down syndrome, and it was fun for my husband to point to my burgeoning belly and introduce it to people as “our daughter Kristin.”

Amniocentesis is invasive, carries risks, and can’t be done until the 15th to 20th week of pregnancy. Now there is a safe, noninvasive, accurate blood test that can be done as early as the 9th week. It analyzes cell-free fetal DNA (cfDNA) circulating in the mother’s blood. It sounds ideal, but there are some caveats. It’s not yet appropriate to recommend it to all pregnant women. An editorial in The New England Journal of Medicine expressed concern that pressures are promoting diffusion of cfDNA testing beyond the boundaries of available evidence. (more…)

Posted in: Diagnostic tests & procedures, Obstetrics & gynecology

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Does Everybody Have Chronic Lyme Disease? Does Anyone?

A deplorable article by Suzy Cohen on Huffington Post is titled “Feel Bad? It Could Be Lyme Unless Proven Otherwise.” It consists of irresponsible fear-mongering about a nonexistent disease. A science-based article would be titled “Feel Bad? It Couldn’t Be Chronic Lyme Disease Because CLD Is Nonexistent Until Proven Otherwise.”

Cohen says:

People often attribute uncomfortable symptoms to aging, stress, or the “aches and pains of daily living,” especially if blood tests and body scans are normal. What if you have Lyme and don’t know it? If you’ve ever been for a walk in the woods, laid in the grass, live in or visited a Lyme-endemic area, or have a pet cat or dog, you may have exposed yourself to Lyme disease and associated co-infections. There is even the possibility of contracting Lyme if you were born to a mother who has been exposed. Tick born infections can also be transmitted from blood transfusions.

That pretty much covers everyone. Who hasn’t been for a walk in the woods, lain down on the lawn, or had a pet? (And incidentally, are there no editors or proofreaders at HuffPo who realize that the past participle of lie is lain and that infections are tick-borne, not tick born?) (more…)

Posted in: Diagnostic tests & procedures, Science and Medicine

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“Postnatal depression blood test breakthrough” or Churnalism?

Postnatal depression blood test breakthrough” proclaimed the headline. The UK Guardian article then declared:

British doctors reveal ‘extremely important’ research that could help tens of thousands of women at risk.

Here it comes. Readers were going to be fed a press release generated by the study’s authors and forwarded undigested by the media but disguised as writings of a journalist.  If only the journo had asked someone in the know about the likelihood of a single study yielding such breakthrough blood test for risk of depression in new mothers.

The story echoed earlier churnalism from Sky News, British satellite television news service:

There is evidence that if you can identify women at risk early you could treat early or introduce measures to prevent or stop the process of the disease.

A study of 200 pregnant women, published in the Journal of Psychiatric Research, found two molecular “signatures” in the genes that increased the risk of postnatal depression by up to five times. One in seven new mothers suffer from depression.
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Posted in: Diagnostic tests & procedures, Science and Medicine

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The difference between science-based medicine and CAM

“Alternative medicine,” so-called “complementary and alternative medicine” (CAM), or, as it’s become fashionable to call it, “integrative medicine” is a set of medical practices that are far more based on belief than science. As Mark Crislip so pointedly reminded us last week, CAM is far more akin to religion than science-based medicine (SBM). However, as I’ve discussed more times than I can remember over the years, both here and at my not-so-super-secret-other blog, CAM practitioners and advocates, despite practicing what is in reality mostly pseudoscience-based medicine, crave the imprimatur that science can provide, the respect that science has. That is why, no matter how scientifically implausible the treatment, CAM practitioners try to tart it up with science. I say “tart it up” because they aren’t really providing a scientific basis for their favored quackery. In reality, what they are doing is choosing science-y words and using them as explanations without actually demonstrating that these words have anything to do with how their favored CAM works.

A more important fundamental difference between CAM and real medicine is that CAM practices are not rejected based on evidence. Basically, they never go away. Take homeopathy, for example. (Please!) It’s the ultimate chameleon. Even 160 years ago, it was obvious from a scientific point of view that homeopathy was nonsense and that diluting something doesn’t make it stronger. When it became undeniable that this was the case, through the power of actually knowing Avogadro’s number, homeopaths were undeterred. They concocted amazing explanations of how homeopathy “works” by claiming that water has “memory.” It supposedly “remembers” the substances with which it’s been in contact and transmits that “information” to the patient. No one’s ever been able to explain to me why transmitting the “information” from a supposed memory of water is better than the information from the real drug or substance itself, but that’s just my old, nasty, dogmatic, reductionist, scientific nature being old, nasty, dogmatic, reductionist, and scientific. Then, of course, there’s the term “quantum,” which has been so widely abused by Deepak Chopra, his acolytes, and the CAM community in general, while the new CAM buzzword these days to explain why quackery “works” is epigenetics. Basically, whenever a proponent of alternative medicine uses the word “epigenetics” or “quantum” to explain how an alternative medicine treatment “works,” what he really means is, “It’s magic.” This is a near-universal truth, and even the most superficial probing of such justifications will virtually always reveal magical thinking combined with an utter ignorance of the science of quantum mechanics or epigenetics.
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Posted in: Clinical Trials, Diagnostic tests & procedures, Homeopathy, Medical Academia

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