The Half-life of Facts

I was watching QI this morning. It’s a show where the facts are “Quite Interesting”, and generally obscure.

This morning the episode said something I was so intrigued with, that I rewound it to.
It stated that “At medical college, they usually teach that half of what medical students will learn, will be considered untrue in 10-20 years. This is termed the “half-life of facts”. That is to say that you know that half of the information will be untrue, you just don’t know which half.”

I found that to be Quite Interesting. Enough so that I decided to look the fact up, and see if there was any truth to it.

Samuel Arbesman, a mathematician at Harvard, titled his new book “The Half-life of Facts”. When talking to the Economist, he stated:

For example, in the area of medical science dealing with hepatitis and cirrhosis, two liver diseases, researchers actually measured how long it takes for half of the knowledge in these fields to be overturned. They gave a whole bunch of research papers from fifty years ago to a panel of experts and asked them which were still regarded as true and which had been refuted or no longer considered interesting. They plotted this on a graph. What they found is that there is a nice, smooth rate of decay; you can predict that every 45 years, half of this particular sort of knowledge gets outdated.”

But why am I citing an article in the Economist. Because you probably know a Dr that is still using that 50% of knowledge that is now outdated. Yet they treat you based on that knowledge.

According to Dr. Michael Gold from the Medical University of South Carolina; To paraphrase:

The half-life of medical knowledge is seven years.”

If Dr’s are not keeping up to date, they may be treating you based on what is now outdated knowledge. We have found one such Dr in the guise of the Medical Advisor of one national Advocacy group

He trained 50 years ago. Based on the half-life of facts, if he finished his training in 1970, by 2010, almost 50% of what he learned is outdated. Some of that is “knowledge” is still stating as fact which is on the groups public webiste. When we recently questioned this knowledge (which we showed with research papers to be obsolete) we were told by the Advisor “I don’t care.” (words in writing).

This attitude by the “Medical Avisor” of a major Advocacy Group for a rare condition leads to several questions.

  1. Why is he holding the position? Is it just that it has some kudos?
  2. How does his obsolete knowledge help patients today to live a better life when other Doctor use that “knowledge” to treat the patient.

Knowledge is Power, but obsolete Knowledge is DANGEROUS!

Continuing education is key to good Doctoring. And that continuing education must include reading recent research on the conditions they are treating and accepting that just because it goes against what they have been taught, doesn’t mean it is wrong, or that the Dr researching and promoting the new information is doing it “for ulterior motives”.

Next time you speak to your Dr, ask him the date of the last Research Paper was that they read? If it is before 2000, then there is a better than even chance that half that knowledge is obsolete, or will be in the next couple of years. Ask them if they have heard the term Half-life Of Facts.

Some will agree, others will get upset because they will be reminded that they are not as up to date as they should be, and others will probably refute the statement, or get angry about it. Most likely the latter, are so well past their half-life with knowledge, that they should perhaps be ignored completely.


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