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How Decision Science Can Make You Floss

Created July 13, 2009 by Laura Turner


Talya Miron-Shatz, PhD, is a decision scientist, studying the way people interpret medical information. She teaches consumer behavior at Wharton and is a keen public speaker, advocating the importance of understanding the psychological aspects of medical decision making.

She recently sat down to speak with SDN about how consumers and health care providers make medical decisions.

What is decision science, and how does it apply to health care decisions that consumers make?

Imagine you are designing a sticker promoting flossing. Should you say, “Flossing helps you prevent gum disease,” or should you emphasize the loss of protection that results from neglecting to floss? It turns out that people are more motivated to act when something they have is about to be taken away from them. So, when you’re in the bathroom at night, being aware of the potential risks to your gums might prompt you to dedicate a few extra minutes to the fine art of flossing. This, in a nutshell, is what decision science is about.

Decision scientists make sense of people’s judgment and decisions, even when these seem random, erroneous or irrational. Decision science was developed by Amos Tversky and Daniel Kahneman, Nobel Laureate of Economics, 2002, with whom I had the honor of working closely at Princeton University. This science draws on psychology and, rather than concluding that people are unpredictable, or just plain dumb, helps explain their behavior.

A really cool thing that decision science does is that it incorporates emotions into the equations. After all, the facts don’t change in the flossing example – what matters is how the information is presented. We show that the way alternatives are presented often dictates, or at least influences, how people feel and the choices they make.

Does this apply to every medical setting?

I always tell my students that there is no such thing as a neutral way of presenting information. The beauty of decision science is that the principles apply across the board, even where you least suspect it.

Consider an expectant mother who arrives at a prenatal clinic. The genetic counselor presents her with a list of the available screening tests for the fetus. Some tests are standard at the clinic, while others need to be specifically opted into. This varies across clinics. When a woman receives a list of, say, seven standard tests and five optional ones, adding the optional tests seems unnecessary, perhaps even overly anxious.

Now consider an expectant mother who arrives at a clinic where all 12 tests are standard, and the counselor tells her she can opt out of five of them. Opting out feels different from opting in. The woman may feel that by neglecting to take some of the tests, she is jeopardizing her unborn child. Thus, she will keep all 12 tests.

Most people tend to stick with the standard option or the default, which means that medical students need to be mindful of what they set as the standard.

What trends do you see in health care decisions by consumers that will impact current health professional students?

The emerging trend is patient autonomy – delegation of choice and decision to patients.  The premise is that, given sufficient information, patients will make the health choices that are best for them. This shift poses a huge challenge to doctors, who are trained to treat patients but not to explain treatment options in a way that patients will easily comprehend. Medical students and residents seldom receive training on these types of communication skills.

Nowadays patients have access to online medical information. Does this make a provider’s work any easier?

You would think that greater availability of information should relieve some of the burden off of doctors’ shoulders, but such is not always the case. Medical information is often presented in a way that is confusing and hard to grasp. Probabilities, which are key in risk evaluation, are a particularly tricky concept.

I showed people text from reputable websites that supposedly cater to a wide audience. It is distressing that fifty percent of the participants misinterpreted what lifetime risk probability means – and this concept is broadly applied.

I also inquired about a test for the BRCA 1 or BRCA 2 gene mutations, associated with increased risk of breast cancer. Half the participants knew that the test could not tell them with certainty whether they will develop breast cancer. Yet about a third of the participants expected this kind of certainty from the test. Just imagine how misguided they were.

Doctors cannot assume that their patients are in the know just because there’s more information out there.

Don’t issues of misunderstanding apply only to certain patients?

People with low numeric skills and low health literacy are more prone to misunderstandings. However, doctors are not so good at detecting patients with low health literacy. Moreover, patients are good at hiding their bafflement, because it is embarrassing to tell your doctor you do not know what he or she is talking about.

Recently I heard about a man who had a prostatectomy. Before the surgery the doctor said, “You are going to be impotent,” to which the man replied, “It’s ok. I already have children.” The doctor had assumed that “impotent” is a common term.

The same thing happens when a doctor explains how to titrate medication. The patient nods, then returns weeks later having never increased the dosage.

Are doctors and medical students themselves immune to miscomprehensions and judgment biases?

Not quite.  In one of the most inventive studies, conducted by Gerd Gigerenzer and his colleagues, a healthy heterosexual white male went to a few dozen doctors’ appointments with a positive HIV test result. Almost all of the doctors told him he had HIV. Only a minority remembered that the test is not 100% diagnostic, that there is a 1:10,000 chance of a false positive result. Various ways of presenting probabilities and risk information help medical students and doctors understand those concepts.

How did you become involved in medical decision making?

I was a grad student in psychology, studying decision science, when the mission of making medical information comprehensible snuck up on me.  One of my professors asked if I might be interested in teaching a decision making course to Masters’ students of genetic counseling. I accepted, then realized I had no idea what knowledge would most benefit my future students.  So I sat in on genetic consultations.

I will never forget the first couple I encountered. The father was albino, and both parents were hearing impaired, so they were accompanied by an interpreter. They also brought their two year old, for want of a babysitter. The wife was pregnant, and the couple wanted to know what to expect from the newborn – what were the chances that he or she would also lack pigmentation and/or be deaf. They just wanted to know. They were also curious as to whose “fault” the baby’s condition would be, mom or dad. It mattered to the mother-in-law, who constantly blamed the husband for the first child’s lack of hearing.

The genetic counselor was just the kind of health expert you would want to meet – highly professional, well-prepared, and very caring. She spread out the charts of paternal and maternal heritage, then methodically explained how genetics worked, starting with chromosomes and genes.

None of this was redundant for me despite my education. I did not major in science and had not taken a biology class since, I believe, the 9th or 10th grade – it had been quite a while. Remembering which was the bigger unit, chromosome or gene, was not easy. I had to dig in my memory to figure out that there were 23 pairs of chromosomes and, well, lots of genes.

Meanwhile, the counselor was explaining this to the translator, who would explain it all to the couple. The interpreter seemed no less bewildered than I was. Information just kept coming in, which had to be conveyed to the couple through sign language. I could not help but wonder what they would say if we asked them to translate back what they’ve just been told.

The couple was physically there, but they were not really listening, and it wasn’t because they required hearing aids. They had gotten lost fairly early. You could see it in their faces. Chromosomes, genes, dominant, recessive – lots of terms, but not a lot of meaning.

Of course, the confusion had nothing to do with being hearing-impaired or albino. It had everything to do with being a patient. For all my fancy graduate training, I don’t think I would have fared any better than they did. The added layer of concern for the baby certainly did not make things easier.

Knowledge doesn’t just pour out of the medical system and into the patients’ minds, I realized. It has to be understood, processed, and dealt with emotionally. It was the counselor’s job to explain and the patient’s job to get it. Leaving the medical center that day, I still thought I was just going to teach decision making to genetic counselors. I did not realize that making medical information comprehensible was going to take over my interests to become my vocation. I did not realize it just then, but that was when my mission began.

For more information on medical decision making, please visit “Baffled by Numbers”, Dr. Miron-Shatz’s blog published on the Psychology Today website:

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