After I graduated Medical School, I went to Stanford for a one week course on computer informatics. It was 1995. I had seen the world wide web before but this was my first exposure to HTML editing. We were shown expert diagnostics systems and an electronic medical record. It was Tomorrow Land for how the computer was going to shape the future of medicine.
The class was organized by Edward Shortliffe, At the time he was famous for this textbook:
It was published in 1990 and a number of our lectures came from chapters in this book. We think of the computerization of medicine as being a very contemporary subject, but Shortliffe was a co-author of a book titled “Readings in Medical Artificial Intelligence. The First Decade,” published in 1984!
The most important thing that I experienced in that course was Bayesian logic. There was a whole day on computer-aided diagnosis and as part of this, there was a lecture on the mathematics of pre-test and post test probability. Learning that there was a mathematical way to make sense of the uncertainty that had been a consistent companion on the wards was a revelation. I had travelled across the country to Palo Alto and Dr. Shortliffe had pulled the curtains of confusion from my eyes. He had shown me the science of medical decision making. It was a revelation.
At that time I was carrying around an HP200 lx, 1990’s ubercalculator/PDA.
It had an amazing programable calculator. I entered the equations for post-test probability and after class excitedly went up to Dr. Shortliffe and explained that I was sure that I could research the sensitivity and specificity of all the tests I needed, but I had never come across any data on the pre-test probability. I wanted to know where I could find that information. He looked at me and told me that the pre-test probability is your intuition as a doctor. You had to assign your own pre-test probability based on your history and physical and other pieces of data.
Intuition…
This detailed lecture with mathematical certainty was at its very core just human, fallible, intuition.
It crushed me. Math wasn’t going to save me.
I hadn’t thought of that moment in my medical education journey until I read The Laws of Medicine. Law 1: A strong intuition is much more powerful than a weak test.
Get a copy of this book and read it, so you can discuss it with #NephJC in the Summer Book Club this August.