A radical transformation in healthcare decision making is needed

I love when an article I read first thing in the morning gets me to think about itself all through my morning chores and then erupts into a blog post. So it was with this little gem in the statistical publication Significance. The author suggests making gambling safer by placing realistic odds estimates right on the poker machines in casinos. He even goes through the generation of the odds of winning and losing and how much based on really transparent assumptions. In fact, what he has in effect constructed is a cost-benefit model for the decision to engage in the game of poker on these machines. Seems pretty simple, right? Just a few assumptions about how long the person will play, some objective inputs about the probabilities, and presto, you have a transparent and realistic model of what is probable.

In medicine, there is a discipline known as medical decision making (MDM), and what it does is exactly what you see in the Significance article: its practitioners construct risk- (and, hence, cost-) benefit models for decisions that we make in medicine. To be sure, these turn out to be rather more complex, since the inputs for them have to come from a large and complete sampling of the clinical literature addressing the risks and the benefits.

But that’s the meat; the skeleton upon which this meat hangs is a simple decision tree with “if this then that” arguments. In this way these models synthesize everything that we know about a specific course of action and put it together into a number driven by probability.

They usually go something like this. We have a group of women between 40 and 49 years of age with no apparent risk factors for breast cancer. What is the risk-benefit balance for mammography screening in this specific age layer? One way to approach this is to take a hypothetical cohort of 1,000 women who fit this description and put it through a decision tree. The first decision node here is whether to perform a screening or not. What follows are limbs stretching out toward particular outcomes. Obviously, some of these outcomes will be desirable (e.g., saving lives), while some will be undesirable, ranging from worry about false positive results to unnecessary surgery, chemotherapy, radiation, and even death. Because these outcomes are so heterogeneous, we try to convert everything to monetary costs per quality of life (quality because there are outcomes worse than death, as it turns out). But what underlies all of these models is the mathematics derived from clinical studies, not pulled out of thin air. This is the most useful synthesis of the best evidence available.

To be sure, MDM models are rather more complicated than the poker example. They require a little more undivided attention to follow and understand. Furthermore, I personally did not get a whole lot of exposure to them in my training, but perhaps that has changed. Like anything to do with probability, these models tend to be off-putting in a society that has consigned itself to wide-spread innumeracy. And doctors are certainly not immune from misunderstanding probability. Yet without them perceptions rule, and our healthcare becomes a reckless gamble. In our ignorance we collude to build profits that come with medicalizing small deviations from the perceived normality. Sadly, the primary interests that drive these profits are not usually doing so with probabilistic forethought either, but rather on the basis of red hot conviction that they are right.

Doctors and e-patients need to lead a radical transformation in how we handle decisions in healthcare. It is very clear that willful ignorance has not served us well, and we are all too easily led into panic about every pimple. Resilience can only come when we question our assumptions. Alas, our intuitive brain is almost certain to mislead us when faced with complex information; why else would we need explicit odds listed on poker machines? The absurd complexity of information in medicine deserves no less. It’s time to start the probability revolution.

Marya Zilberberg is founder and CEO of EviMed Research Group and blogs at Healthcare, etc. She is the author of Between the Lines: Finding the Truth in Medical Literature.

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  • doc99

    The stakes are considerably higher than money. Ask my sister whose breast cancer was discovered on a “routine” mammogram. 

    • sFord48

      The question is whether that “routine” mammogram saved your sisters life.  It’s more likely that she will undergo unnecessary treatment for a cancer that would never threaten her life.  

  • http://twitter.com/OurH_careSucks John Lynch

    I couldn’t agree more, but would add that the obstacles to imposing more probability logic on our healthcare decisions are enormous: physician burnout/indifference, medical profiteering, patients’ fear of death that’s often stoked for personal gain. We need a way to convey to patients the probability of harm from the treatments they cavalierly seek out as if they were risk-free.

    In other words, we need to stoke their fear of, and respect for, medical treatments to balance their inordinate fear of death form disease – sort of like the academic detailing with doctors to counter the hype of drug detailing. 

    Only with patients, it would need to be very graphic and straightforward…maybe like the poker machine suggestion. After all, their medical treatments are very often much more of a gamble than patients realize.

  • http://www.facebook.com/profile.php?id=826734007 David Hanson

    Nice idea but it seems that logical thinking doesn’t work in the real world.  An up to date example is the controversy over PSA testing.  Statistics have shown that PSA testing for the general population of men is more harmful than helpful.  It is better for the men not to know their PSA level because acting upon a high level causes more harm than the small number of prostate cancers that will actually kill someone (almost all with prostate cancer will die of something else if left alone).  And all the others with prostate cancer that wouldn’t have died are harmed (including death) by the procedures and treatments.  So the logical thinker, both doctor and man with a prostate, will decide not to have a PSA test.

    But apparently there are few logical thinkers — there are:

    1. The urologists that stand to lose money if PSA testing is not done.  They are definitely for PSA testing.
    2. The politicians which all seem to have spines of jelly — they even make a law that Medicare has to pay for PSA’s whether they are harmful or not.
    3. The men who “know” that they have been saved from death caused by prostate cancer JUST because they were told that they have prostate cancer and their prostrate was removed and, hey, they didn’t die. The  vast majority of them would not have died but in their emotional not logical state, they won’t even consider that.
    4.  The men who have been brainwashed to believe that the PSA test will keep them from dying of prostate cancer — and who will not consider otherwise.
    5.  The men who when they are told that they have prostate cancer only have one thought — GET THAT CANCER OUT OF ME — don’t try to tell them that it should be left alone (I just saw a CBS video where a supposedly intelligent famous college coach stated this).

    Sounds pretty hopeless to me.  And all of this applies to mammography also.  The women and the breast cancer specialists are just as incapable of rational thought as the men.

  • http://profile.yahoo.com/BHBJVIZ7O27NQQYEECHAR32RTY Wesley

    I recall reading an article about PSA tests and how they do more harm than good.  In the article they interviewed a physician from a hospital that had just acquired a proton beam therapy machine.

    The physician was livid at the thought that anyone would dare to suggest that PSA tests not be done routinely.  My first thought was, “Well, those machines are expensive and have to earn their keep.”

    The physician reminded me of what Mark Twain wrote, “You tell me whar a man gits his corn pone, en I’ll tell you what his ‘pinions is.”

  • karen3

    Most medical models fail to include one very critical cost to patients — the tangible and intangible costs of ill health, for both the patient and his/her family. It’s not just the costs of what is least cost of medical care, it is a question of least cost total.  And there is only person who can make that judgment — the patient, not the doctor.  What is the right treatment for a patient, what is the right choice, is something that depends most on what is important to the patient.