
Managing Difficult Decisions in Medicine with the 40-70 Rule - psufka
http://paulsufka.com/difficult-decisions/
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icegreentea
It's interesting that they bring up Colin Powell in this, particularly because
the big 'flaw' with this type of advice is lies in something that Donald
Rumsfeld is infamous for saying - his so called 'known knowns' (or conversely,
unknown unknown) phrase.

You're ability to even judge that you have 40 to 70 percent of the information
required isn't even a given. In particular, especially with something like
medicine, where there is time pressure, bizarre individual circumstances,
confounding issues, it can make it difficult to really compress your current
state of knowledge into a single value representing percentage of 'known'
information.

That said, hilariously if you look at the reproduced slide in the bottom, the
blog post and the slide actually say different things.

Colin Powell says to act when you have between a 40 to 70 percent chance of
being right given your current state of knowledge/information. The slide says
acts when you have 40 to 70 percent of the necessary information.

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corysama
The article is copy-pasting what seems to be a widely spread misquote of Colin
Powell. What I think is the actual quote seems less controversial than the
"What defines 40% of the information?" issue that is being debated here.

> Part I: "Use the formula P=40 to 70, in which P stands for the probability
> of success and the numbers indicate the percentage of information acquired."
> Part II: "Once the information is in the 40 to 70 range, go with your gut."

So, Powell was actually talking about confidence in success, not percentage of
information. Confidence is explicitly an estimate, whereas "percentage of
information" is clearly unknowable in the situations being discussed.

The original collection of Powell quotes that included this one is a lot more
interesting and valuable than this particular article, IMHO.
[http://govleaders.org/powell.htm](http://govleaders.org/powell.htm)

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LinaLauneBaer
This is not always a good approach. It can only be used as a rule of thumb.
Here is a counterexample:

I had to go to the hospital because of extreme pain. The doctors were pretty
sure that I have some kind of auto immune disease which could have been
treated with immunsuppressive drugs. They artificially delayed the treatment.
If they had started the treatment immediately I would have felt better sooner
but also some symptoms which only manifest itself after a certain amount of
time would have never been seen. So for a long time we only had a imprecise
diagnosis. It would have been enough to treat it but it would have also hidden
many symptoms which were needed for a more precise diagnosis.

Especially if you have a chronic disease you want a very precise diagnosis
because you will be treated for the rest of your life. If the treatment is not
as effective as it could be you will have problems in the long run.

So they gave me very strong pain killers and let me rot for 2 weeks or so.
Then the treatment began and it took another 3.5 months once I was released
from the hospital.

I am happy that I now have a better near optimal diagnosis.

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crazygringo
Where do the '40' and '70' come from? Who's defining what the final amount of
available information is, and judging what the current percentage is? How do
you even know at the time?

I mean, it would be one thing to create some kind of simulation and discover
that this was actually something statistically meaningful. But there aren't
exactly any citations here..

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jsprogrammer
It's really just pseudo-scientific hand-waving to make people feel better
about decisions that they make.

As you noted, if this was something more than that there would be simulations,
citations, examples, or really anything, other than feel good puffery.

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appleflaxen
Without any data behind this, it's just one more wacky theory of management
that is being promoted without skepticism.

It's a bit like "brainstorming", the strategy of idea generation that has an
appealing narrative, but doesn't result in greater creativity when measured
objectively.

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ams6110
I have to admit it's not what I guessed it was. From the title I thought it
would be something like "under age 40, treat aggressively, over age 70, just
take away their pain."

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sigmar
Of course a decision can't be made with 0% information, and waiting for 100%
information in unnecessary. But how would one arrive at the range of 40-70%?
For a decision about risky surgery I would hope that the amount of known
information is much closer to 90%.

"40-70 rule" seems like a banal remark once you realize different decisions
require different amounts of information

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ams6110
If the surgery is truly risky, it may be impossible to know even 70% of the
information. Risky surgery tends to be rare, and the people who need it tend
to have more than just one problem, which compounds the number of variables
that can affect the outcome.

