Tuesday, October 19, 2010

"The illusion of certainty"

This post was in part inspired by my recent exchange with e-Patient Dave. But really I have been thinking about this for quite some time now, and Dave provided the necessary nudge for me to write about it. Hence, his words, "the illusion of certainty".

As I like to tell my students, in science we are always on the way. We never really reach the end of the road because science is advanced through curiosity and constant questioning. For this reason, even when we think that we know something, think again. This reality is anathema not only to our model of medicine, but to our current model of society as well. What do I mean by that?

Well, let us reflect on our system of education. My son has a science workbook developed by what s considered to be a fairly progressive curriculum group. One of the early sections deals with the Linnaean classification of the animal kingdom (yes, the King Philip Came Over From Germany... well, not exactly sober). The worksheet asks the student to fill in blanks in a paragraph with the appropriate gradation of the classification. And believe it or not, the top of the page sports the full list of these strata. So, what is the message? The message, as I see it, is that this classification is so important and so solid that it requires rote memorization, as it is the only correct answer. Is this really true? Almost every day we hear about organisms requiring reclassification because we learn something new about their features that excludes them from their previous cubby. Bacteria have gained their own domain, which they did not have when I studies them in college. So, what is important here? What is important is why it is that we need these classifications, as well as how they are developed. My son is learning more from our explorations of what animals do not fit neatly into this system than from regurgitating the 7 vocabulary words. He is also learning that science is messy and the illusion of certainty that our educational systems foster are a house of cards. We could extend this argument to the way we test our children's knowledge in school as well, reducing what they learn to only one neatly packaged correct answer with all of the rest being wrong.

Now, let us wander into other parts of this American life. Take for instance the advertising industry. Cleverly they have devised market segmentation schemes that allow them to target products with very specific characteristics to a very specific population of consumers. (I wish we could be as good at doing this kind of a subgroup analysis in clinical sciences!) We are told with certainty that Charmin is better than Scotties, that Gif is more natural than Peter Pan, that buying Ford is more patriotic than buying a Toyota. And even though we are constantly faced with an absurd volume of choices, we are somehow under the impression that there is only one that is right for us.

My final example is in politics, which these days cannot be separated from religion in the US. Our politicians have realized that reducing every important issue to two ways of addressing it, and from those two ways choosing the one that can get them the most votes is indeed the way to get elected and re-elected, so that they can have a constant wedding banquet without ever getting bogged down in the hard work of marriage. This falsely reductionist and dichotomous approach has led us to a deeply divided nation, where, although we are more same than different, it is indeed these differences that are amplified to a deafening hysterical pitch. Yet, we are all secure in our certainty of being right.

I used these examples to illustrate our dependence on certainty in some major aspects of our every-day lives. This paternalism of certainty in education, politics and trusted brands likely extends to the sense of entitlement to certainty in healthcare as well. When I was in practice and on call for my group one Saturday morning, with a line out the door and the ancillary personnel about to go home for the day, I walked into one of the examining rooms to greet a woman in her 40s, well dressed and groomed, and not appearing in the least distressed. Immediately she let me know that she was being seen for a cough that was going on for a couple of days (no, she was not a smoker and did not have any chronic conditions), and wanted to nip it in the bud with a prescription for an antibiotic. After listening to her thoroughly and ascultating her lungs, I came to the conclusion that her ailment was overwhelmingly more likely to be viral than bacterial, and an antibiotic was not indicated. I shared my thinking and probability analysis with her, and following my thorough explanation of why she was going to leave my office empty-handed, she responded, "But my doctor always prescribes me an antibiotic!" I looked at her with incredulity, glanced at the growing line outside my door, and then at the clock, and, though I am not proud of it to this day, I pulled out my prescription pad. Her expectation of certainty did not leave any room for probability-based thinking, and her physician, and now I, were colluding in continuing this deception.

Today I look at medicine from a completely different perspective. As a clinical researcher, I am keenly aware of all the uncertainties inherent in what we do. The richness of research is in asking the question, and getting the answer, though it gets us published, is but a fleeting pleasure on the way to the next question. Science is the classic example of "there is no there there"; it is the road that is the gift. In the clinician's office, this attitude becomes difficult to hold together with the need for answers and certainty. Yet hold it we must. Yes, we have to give patients the best care possible based on what we know. But we cannot for a moment forget that all knowledge is evolving. This epiphany is an invitation to physicians actually to work with individual patients and their values and wishes to the extent possible. Dogmatic certainty, the alternative, is tantamount to worshipping at the altar of a false god.        


  1. Excellent post. I don’t know enough to appreciate the value of a probabilistic approach, but I couldn’t agree more that we need to acknowledge how much we don’t know and that we proceed with false confidence. This is interesting to me historically. We started down the path of biological reductionism in the late 19th century with the idea of specific etiology. The patient in his or her lived environment, which is where health happens, receded from view. The problem that interests me is not how to proceed further down the path we’re on, but whether the medical profession will be able to acknowledge that simply improving health care and making it more available is not the only way to improve population health. Of course, the uncertainties in trying to understand the social determinants of health are, if anything, more challenging than those of clinical medicine. But the highly attractive promise that more science and mathematics will solve our problems is what keeps that path almost exclusively funded and in the forefront of research and policy agendas. I really hope I don’t sound like a Luddite in saying this. That’s not my intention. I merely wish there could be more balance.

  2. Dear Jan, thanks so much for leaving your comment. I love your historical perspective. I have thought about this issue for a long time as well, and will do a post on it at some point.
    I also agree that social determinants of health are far more important, yet harder to study. There is an old paper from the Rand Corporation that I discussed in a post (with a pie chart) a number of years ago that laid out what contributes to early death, and access to medicine accounted for 10%! The rest was spread nearly evenly among socio-economic, behavioral and genetic.
    My point here and in yesterday's post applies only to disease, not to health. I have blogged ad nauseam about how health should not be subjected to the same calculus -- just look at all the "screening yields false positives" posts I have done. So, just to be clear, probability is important in all aspects of life, but my push in medicine specifically is to use it to 1). avoid medicalization, and 2). make better decisions in the setting of illness,
    Thanks again for your comment.