by Sarah Gilman-Short, MD 2010
Writing this article has been an interesting journey. A few weeks ago I turned on the radio to hear some pundit screaming, “this is just the first step with this health care reform – first they’re taking away our mammograms, then they’re going to start rationing everything!” I wanted to call in, but instead I prepared myself to shoot off a fiery retort extolling the new guidelines and explaining the importance of evidence-based medicine, public health, and risk-benefit analyses. However, after looking at all sides of the issue, I see that things are much more complicated than I had previously thought and my position is much less clear (who’s fair and balanced now, Fox News?).
So now, with the utmost humility and effort, I bring you a primer on the complicated relationship between doctors and numbers, using the recent change in the recommended guidelines for breast cancer screening as an example. And there may be a little rant about health care reform for good measure, but I’ll try to tone down the politics as best I can.
Personally, I’ve always distrusted numbers; they’re shifty and unfriendly creatures. In the third grade, I literally shook with fear before every timed arithmetic test. However, medical school has forced me to confront my numerophobia, and, although I still do not like the little buggers, I have come to deeply respect their utility in my profession. I see myself as an artist and humanist foremost, and I fully believe in the power of individualized care drawing heavily on a strong relationship between the doctor and patient. However, if doctors didn’t care about hard evidence and science, we’d still be running around “blood letting” everyone with a fever. This is one of the biggest challenges of medicine – we have to merge the evidence we’ve been given (which can be somewhat dodgy itself) with our own intuition and first-hand experience in order to make the right decision for the unique patient in front of us. Sometimes the numbers are right and sometimes they’re wrong, but usually those evil numbers win.
This brings me to the new breast cancer guidelines. If you haven’t yet experienced the treat of being hollered at by a media pundit (and I do recommend it; quite exhilarating during your morning commute) I’ll give you a quick explanation. The United States Preventive Services Task Force (USPSTF) is an independent board of “experts in health prevention and primary care” who have taken on the formidable task of pooling all the evidence from multiple clinical trials regarding a particular subject. They mix all the studies together in a huge pot, add some eye of newt and rat’s tail, mutter a few incantations, and then poof…an evidence rating is set, a guideline is published, and all the primary care physicians in the country collectively gasp together, recognizing that they’ve been doing everything totally wrong their whole career. This happens, oh, about once every few months, and has included everything from abdominal aortic aneurysm screening to youth violence counseling.
The concept of an “evidence rating,” although somewhat boring, merits discussion. Theoretically, the strength of evidence behind every decision that doctors make can be distilled down to by the USPSTF to a single letter. There are tons of really good studies that unequivocally say that cigarette smoking is very bad for your health; therefore, counseling patients to stop smoking is grade A, or strongly recommended. Grade B means that there is “at least fair” evidence to support the service. Grade C means that the USPSTF makes no recommendation for or against the service and D means that the service is either ineffective or actually hurts patients (thus the USPSTF recommends against it). There is one more distinction – called “I Statement” – which means that there is insufficient evidence to make any kind of decision whatsoever. In theory, the letter is determined by a weighing the risks of a particular service against the strength of evidence for the benefits of the service. Telling your patients to stop smoking is not risky and it can have a huge benefit for people; hence Grade A.
So what happened with breast cancer screening? The smart USPSTF people set the sights of their mystical computer programs on breast cancer screening. And they came up with the following results:
1. The USPSTF recommends biennial screening mammography for women aged 50 to 74 years (Grade B Recommendation).
2. The decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take patient context into account, including the patient’s values regarding specific benefits and harms (Grade C Recommendation).
3. The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of screening mammography in women 75 years or older (I Statement).
4. The USPSTF recommends against teaching breast self-examination (Grade D Recommendation).
5. The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of clinical breast examination (CBE) beyond screening mammography in women 40 years or older (Grade I Statement).
6. The USPSTF concludes that the current evidence is insufficient to assess the additional benefits and harms of either digital mammography or magnetic resonance imaging (MRI) instead of film mammography as screening modalities for breast cancer (Grade I Statement).
Now let’s try it in English. If the USPSTF were a normal person standing in front of you, it would say: “If you’re a woman between 50 and 75 years old, there’s pretty good evidence that you should get a mammogram every two years. Even though there seems to be a significant amount of evidence, I don’t really know if it’s a good idea to get a mammogram if you’re between 40 and 49 years old, so I’m going to leave that up to you and your doctor. And there definitely isn’t enough evidence at all to say if you should have one after age 75. As for your self-breast exams, they’re either totally ineffectual or harmful, so you probably shouldn’t do them. There isn’t enough evidence to prove if your doctor’s clinical breast exam is useful. Lastly, there isn’t enough evidence to prove that special studies like digital mammograms or MRIs of the breast help more than they hurt people.”
I don’t know about you, but if the USPSTF were my doctor, I would be writing some really angry Yelp reviews. The USPSTF doesn’t know anything about me, doesn’t care about me and all of this talk about evidence and proof doesn’t mean anything to my or Teresa Heinz’s tatas. At the same time, the USPSTF is not sexist or intrinsically evil. The USPSTF, with all its unfriendliness, doesn’t care about money. It only cares about large-scale risks and benefits – which, in the case of breast cancer, involve unnecessary biopsies, further imaging, and psychological stress weighed against the possibility of a life-saving early intervention. I think that, even though you have to do 556 mammograms to diagnose 1 case of invasive breast cancer in women 40-49 years old, it’s still worth it. Conveniently, the American College of Obstetricians and Gynecologists as well as the American Cancer Society agree with me.
This brings us back to the struggle between the individual and the public good, which has been at the root of the health care debate. In this case, I chose to ignore evidence (albeit wishy-washy) and to potentially ignore economics to come out in favor of the one woman out of 556 who benefits from getting a mammogram between the ages of 40-49. Wouldn’t you? At the same time, I’m not completely satisfied with this decision. As I said before, the USPSTF doesn’t take cost into consideration, and I think that cost-effectiveness should always be taken into account when deciding whether or not to perform a test. Despite the way we’ve historically practiced medicine in this country, our money and resources are not infinite. It feels ugly to merge economics with medicine, but the truth is that we, as a nation, have become very good at providing incredibly expensive health care of questionable quality to the “haves” while neglecting the “have not’s,” bankrupting the American people along the way. America’s pathetic rankings on the full spectrum of health indicators reflect this discrepancy (for example, we rank 33rd in the world for infant mortality…behind Brunei, Cyprus, and New Caledonia. We’ve included a lovely picture of Brunei for those considering relocation). We all might have to make some individual sacrifices to provide the greatest good for our society as a whole. We’re working on it, but we still have a long way to go.
 The real and much less interesting version involves a series of ugly calculations that I shudder to think of.
 It really is! Seriously, don’t do it!!!
 It also helps to repeat the message. So this is meant for you. Don’t do it.
 Population Reference Bureau, World Infant Mortality Rates, 2008
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