Medical decisions can be extraordinarily difficult. They involve our most valuable asset: or health and they almost always involve some uncertainty.

Medical decisions have large stakes

Because the complex of the human body we can’t know outcomes in advance. They can generate strong emotions elicit our deepest fears and fill us with regret. They are difficult but important. We want to make the right decisions about her health. You might think that because medical decisions have such large stakes they wouldn’t be influenced by the biases I’ve introducing the previous articles, but they are.

Let me tell you about a simple experiment run by Peter Ubel who is both a behavioral economist and a physician. Here’s the dilemma, fortunately it was hypothetical, that he gave to his participants. Suppose you are diagnosed with a form of treatable cancer. For now let’s assume that it is colon cancer.

Your physician comes to you with two courses of treatment, what she calls the complicated and uncomplicated surgeries. The uncomplicated surgery has only two potential outcomes, both with well-defined probabilities there’s an 80% chance of the surgery goes as expected and you will recover completely with no ill effects no other health issues and no chance of cancer recurrence, but there’s also a 20% chance you’ll died during surgery.

People prefer these complications to death

The complicated surgery is pretty similar but it has slightly different outcomes: there is an 80% chance you’ll recover completely with no chance of recurrence and no ill effects just as before and now there’s only a 16% chance you’ll die during surgery, but there are four unpleasant potential complications each occurring in 1% of the patients who survived the surgery cancer free.

There could be severe scarring, uncontrollable abdominal pain, recurring diarrhea or colostomy. The only difference between the uncomplicated and the complicated surgeries is that a 4% chance of dying in the uncomplicated surgery is replaced by 4% chance of various unpleasant surgical complications.

Now Ubel first asked for dispense about their preferences for the surgical complications. When participants were asked which is better: severe scarring or death? They’ll say severe scarring the same answer held for all of the different complications. After all people go through surgeries all the time, that saved their lives but reduces their quality of life in some way. People prefer these complications to death.

Factors that influence how we make medical decisions

But when Ubel asked participants about their preferences for the surgeries, there was a surprising result: a majority of people in his experiment pick the uncomplicated surgery, the one with a higher chance of death . Now that choice just doesn’t make sense, at least if one assumes that patients make decisions by comparing the set of outcomes associated with each potential treatment.

The same people prefer the outcomes of the complicated surgery individually, but when faced with the surgeries as a whole they pick the uncomplicated surgery. This result is emblematic of the puzzle of medical decisions, they are high-stakes important decisions, there’s lots of information available, there’s usually a physician or other expert to help and yet people make what seem like objectively bad decisions.

In today’s article all discussed three factors that influence how we make medical decisions: (1) how we deal with uncertainty, (2) how we evaluate good and bad outcomes and (3) how we are guided by others opinions.

Decision-making elicits the same biases

In one sense there’s nothing special about medical decisions, all these factors influence non-medical decisions as well and we don’t have any sort of brain module specific for medical decisions, but in another sense medical decisions are special, they involve our bodies our capacities our sense of self even life and death.

So I’ll balance describing how medical decision-making elicits the same biases as other forms of decision-making while also giving some insight into some key differences before I discuss each of those three factors in more depth let’s see how they can jointly explain the decisions in Peter Ubel’s experiment.

First let’s think about uncertainty. Remember from the lecture probability that a core finding a behavioral economics is that people give too much weight very rare events. An event that objectively has only a 1% chance of occurring might seem subjectively as if it had a 5% chance of occurring. So the surgical complications may only each of 1% chance, but they influence the decision subjectively much more.

Second let’s consider the vividness of good and bad outcomes. These surgical complications were specifically chosen because they seem rare and scary. It is frightening to consider life with constant abdominal pain or occurring diarrhea, vivid outcomes carry more weight in our decisions.

Third let’s evaluate the role of others opinions on our decisions. These outcomes are not just personally unpleasant they both discussed in others. We don’t want to face the possibility that a surgical complication might alienate our friends or family or might diminish our self pride. Together these three factors lead to paradoxical medical decisions.

People would rather have the surgical complication to death if either was certain, but they’d rather have a surgery with an increased risk of death the one with the lesser risk of death along with those complications.