Thursday, February 13, 2014

Prospect Theory In Patient Empowerment for Medical Decision Making

Is that a decision tree an Iva stick figure?
Iva Pairabigglutees was just informed she has diabetes and needs to start taking medicines.  Since she is leery about taking pills, she quietly wonders why she can't cure herself with a diet. Little does her doc know that she doesn't intend to follow her medication instructions. She also doesn't know that Iva's poor diabetes control is destined to undermine the clinic's pay-for-performance bonus payment.

What went wrong?

The answer, according to this JAMA article, is that the doctor didn't deploy a behavioral economics framework to support Iva's decision-making.  One such framework is the "prospect theory" model that boils patient decision-making into a "three step heuristic."
 
As the DMCB understands it, prospect theory makes the unspoken biases that we all have more explicit.  By identifying all the background assumptions and preferences that patients bring to the physician's office, decision-making can be crafted so that everyone (family, doc and patient) is on the same page.

Briefly, the three steps are:

1. Simplify choices by focusing on the key differences between the treatment options, such as survival rates, quality of life, costs or side effects.

Iva wants to lose weight, while the doctor wants the measure of blood sugar control, the A1c, to be below a target.  What Iva didn't know is that she might live longer (survival) to see her grandchildren (quality of life) by taking a once-a-day generic (cost) with minimal side effects. What the doc doesn't know is that Iva could care less about P4P.

2. Understanding that patients prefer greater certainty when it comes pursuing gains and are willing to accept uncertainty when trying to avoid a loss.

In contrast to a patient battling cancer with a "nothing to lose" attitude about the option of toxic chemotherapy, Iva isn't about to "lose" anything: she otherwise feels well.  No wonder why some, including the Disease Management Care Blog, thinks pay-for-performance should be extended to patients (dubbed "P4P4P").  Iva is far more likely to respond to the certainty of, say, a discount on her next purchase at Whole Foods.

3. Cognitive processes lead people to overestimate the value of their choices thanks to survivor bias, cognitive dissonance, appeals to authority and hindsight biases.

Iva's favorite TV show is The Biggest Loser, but what she doesn't know is that for every successful dieter there are dozens that never make it.

Naturally, the DMCB is taking a very complicated topic in a densely written article and simplifying things, but it hopes the point is made.

CODA: the current blunt-force approach to the measurement of health care quality falls fall short of recognizing the sophisticated approaches like prospect theory and assisted patient decision-making.  After Iva has had a chance to review the pros and cons of the various options for diabetes control, she still may choose to try a diet.  We should be measuring how often patients are given a choice about their A1c, not how many achieved A1c target levels.

Image from Wikipedia

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