Dr. Brush’s roulette wheel also reminded me of the recently released Senate election simulator in the New York Time’s website (http://www.nytimes.com/newsgraphics/2014/senate-model/). Towards the bottom, the reader has the option to “spin the wheels”, so to speak, to get an understanding of the probabilistic nature of election forecasting—which I thought was a fascinating and intuitive way to illustrate this concept. As we continue to iterate our EHRs and it becomes a routine aspect of clinical encounters, there should also be opportunities to apply insights from fields such as data-driven journalism to improve how we communicate probabilistic risk to patients, building on the principles such as those elucidated by Dr. Montori’s work.

]]>I signed in to comment on Dr. Brush’s excellent book and found that Dr. Krumholz has done so already. It is a beautifully written, clinically pertinent, and free book that would be especially helpful to students, trainees, and all medical providers that make daily medical care decisions.

]]>I think your decision aid is excellent. It is very intuitive and easy for patients. Your work on decision aids and shared decision making over the years has been tremendously important.

I tried to create a visual explanation that mimics what the risk calculator actually does. As you well know, the risk calculator doesn’t go back into the pooled cohorts to find 100 people just like the patient whose risk is being calculated. The pooled cohorts only had 1647 black men, and there were probably very few people who exactly matched the description that I gave in my example. Rather, the investigators use the cohorts to derive beta coefficients that are used to calculate the risk. The beta coefficients give a measure of how risk increases for each unit increase in each covariant and this method enables to calculator to interpolate through data sparse segments in the cohort. Thus, the calculator gives calculated risk, not an observed frequency of risk.

I like the roulette wheel analogy because the design of the roulette wheel demonstrates propensity, as well as the play of chance. It also makes it obvious that for a single individual there is only one chance to make a choice (one spin of the wheel). Seems harsh, but that’s the grim reality. The choice and baseline risk determine the design of the roulette wheel that will determine the outcome.

I present this as food for thought. It would be interesting to test whether patients easily understand a roulette wheel decision aid. In the meantime, I will continue to use your excellent resources for decision aids. Thanks.

]]>The book is free on iTunes. I highly recommend it.

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