When Doctors Don’t Do Numbers

December 9, 2015

Dr Amy Price

Dr Amy Price

At a high impact conference I overheard a touching emotional exchange between a group of doctors. Their care and concern targeted my attention. At first I was warmed by their compassion for their “fallen” mate.. What I heard next rocked my world. As I listened it became clear that these doctors were incapable of assessing risk in their own lives. I worried, how much more would this trickle down into the lives of their vulnerable patients. Here is my story, I wish I could say it was an isolated incidence but it is not.

Fatalism Fueled by Fear is Not Medicine

The doctors gathered protectively as one shared his fear.  He had purchased a direct to consumer genetic analysis and the “results” showed he carried a genetic variant that is a risk factor for Alzheimer disease (the APOE gene).  He was unaware there were multiple variants of the allele or that he had to have two copies of the offending variant not just the APOE gene to significantly increase his chances of dying with AD. He was past the age for early onset AD, a critical risk factor and had not considered environmental or lifestyle modifies that could reduce his risk and increase his quality of life.

How Realistic are Direct to Consumer Genetics?

The genetics company stated he had an APOE gene with 100% certainty and implied this increased his risk 50%. As they knew no better, he and his friends mixed certainty with percentages and made the fatal assumption that because prevalence or lifetime incidence is increased after 80 he had a 100% “chance” of dying with AD. They stated they were pretty certain but that they really don’t “do” numbers. In reality his chances were likely less than 3%.  He had not even begun to show signs of dementia and had a recent normal neuropsychological exam but he had given up everything just waiting for AD to take his life.

This three-minute video from risk bites explains clearly why data without information skills to decode it could bring harm just like it has for this doctor.


Values Without Evidence Can be Deadly

I was a recipient of  “values” based medicine without evidence. It was a cruel task master that ate a lifetime of savings while holding out the false promise of a “cure.”

It was worrying the physicians who thought they were giving their best did not know the incidence, prevalence, or false positives for disease. They embraced the concept of treating patients and helping them make “shared decisions” about risk.  I heard them dismiss evidence-based medicine with disdain as “those bean counters who eat their own” and “are always reporting problems instead of providing solutions”.  These doctors offered their colleague affection, moral support and future financial aid. They lacked what was life saving and could help their friend most. An evidence based strategy with a knowledge of basic risk. Compassion is not enough.

Learning Risk is not Dead Easy

Learning risk is not intuitive for most of us. We need to merge bridges of compassion and understanding with a safe place to learn.  I find I still need to refresh my evidence-based skills to use them with confidence but I have tools. I am thankful for my Evidence Based Health Care  https://www.cebm.net/education-and-training/dphil/ training at the Center for Evidence Based Medicine https://www.cebm.net/.  I am grateful that they identified themselves as evidence-based or I may never have found them.

Join us at Evidence Live 2016

Want to learn more about Evidence Based Health Care? Come to Evidence Live 2016 or take a module about evidence through CEBM at Oxford.

Not ready yet but willing to learn more?

See this excellent article BBC article  http://www.bbc.com/news/magazine-28166019  Do Doctors Understand Risk ?  Check out the Understanding Uncertainty  interactive web site by Sir David Spiegelhalter http://understandinguncertainty.org It is great for examples tutorials and to figure out what to do about your own risk.


Dr Amy Price is a D.Phil Student in Evidence-Based Heath Care at the University of Oxford.


Twitter AmyPricePhD

3 comments on “When Doctors Don’t Do Numbers

  1. AvatarMarjorie Kirkpatrick

    This reminded me of my first encounter with genetics in 1966, age 17. My family Doctor had just told me tbat my brother and I each had a 50/50 chance of inheriting our mother’s congenital heart deformity of the left
    ventrical, He added that as I was also female it would be more likely to be me. I asked him if I would get to 50 and go through the same thing as my mum. He said “Your mum’s heart could have gone at any time. It was a miracle that she survived two pregnancies. The specialist was amazed she lived so long. I tried to put the news out of my mind but it was hard to live with the grim reaper in every shadow. My brother had his first heart attack age 40 and survived another ten years. I eventually reached my late 60s and concluded that I have inherited my father’s heart. I would have been so much better off not knowing that I had a 50% chance of heart disease.

  2. Hi Marjorie,
    Thanks for your comments. These are really good points and also apply to some of the screening tests. They are diagnosing people too early to help them and instead of living those years in peace they live with worry and dread and some even have unhelpful procedures. Screening is checking everyone for a problem whereas observant medicine knows the evidence and finds disease early and treats it at the best time for maximum recovery.

    The other issue is evidence and medicine need to be current as what people thought 20 years ago may have been replaced by a better alternative or way of doing things.

    Maybe this is what happened with your mom. I think it would be great if more attention was paid to the impact of what is said to a patient, as probabilities are not certainties but they can be interpreted this way when they are delivered by a person who is considered an authority figure like a doctor.

    The doctor can walk away but the patient can carry those words for a lifetime as you did.

  3. Nice post, Amy, thanks for sharing.
    Like you, I continue to be amazed at how people in number-intense professions rarely use their education in their personal lives.
    But to be honest, most practitioners believe such education magically imparts immunity to them.

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