CART and the Best-Seller Blink
Blink, a New York Times best-selling non-fiction book by Malcolm Gladwell, is a fascinating investigation into a person's ability to make instant judgments and decisions, as well as into the factors that help or hurt the judgment process. In Chapter 4, Gladwell discusses the problem of diagnosing individuals who arrive at a hospital emergency department with chest pain. Doctors need to quickly determine whether the patient is having a heart attack or is at risk of having a heart attack soon. The author discusses a computer-driven protocol based on research by Lee Goldman that, in a controlled experiment at Cook County Hospital in 2000- 2001, was proven to be dramatically more accurate than the judgment of physicians.
The footnotes and references at the back of the book show that such a computer-driven diagnostic protocol was first developed in a classic paper written in 1982 by Lee Goldman and CART author Richard Olshen, now widely assigned reading in medical schools. This landmark paper was updated by Goldman several times between 1982 and 1996 using CART on larger data sets drawn from several hospitals. The results of the trial at Cook County Hospital were published in the Journal of the American Medical Association in 2002.
This example clearly shows that CART used in a real world setting may easily outperform the judgment of experts. Part of the appeal of CART in this circumstance is the ease with which the diagnostic logic can be followed by non-statisticians. This study is also an example of how CART is having a behind-the-scenes impact on processes that touch many people in their day-to-day activities.