
Gait Speed and Survival in Older Adults - colinprince
http://jama.jamanetwork.com/Mobile/article.aspx?articleid=644554
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jmharvey
The basic result (old people who walk faster live longer than old people who
hobble around) shouldn't come as a surprise at all: if you see two 75-year-old
women at the mall, and one breezes by you like she has somewhere to be while
the other shuffles past slowly, and you had to bet on which person had longer
to live, you'd pick the fast one.

The interesting part is how strong the result is: "Predicted survival based on
age, sex, and gait speed was as accurate as predicted based on age, sex, use
of mobility aids, and self-reported function or as age, sex, chronic
conditions, smoking history, blood pressure, body mass index, and
hospitalization."

That's pretty remarkable. For a given age and sex, all of a person's headline
medical information, taken together, is as good an indicator of longevity as
their walking speed is.

~~~
T-hawk
Of course, the gait speed itself takes as inputs many of the rest of those
factors. Smoking history, body mass index, and chronic joint or muscular
conditions all pretty directly affect one's ability to walk fast. So gait
speed turns out to be a very convenient, easily measured proxy for those other
variables.

~~~
k2enemy
Right. I think the way to think of it is that in the context of survival, gait
speed is a convenient and easily measured sufficient statistic for all this
other stuff.

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rjknight
This is _not_ saying that adopting a faster gait speed will cause you to live
longer. It's saying that a person's gait speed is a good indicator of how much
longer they're likely to live. To me, it seems likelier that there's a common
factor which causes both slower gait speed and death, so how fast you _try_ to
walk isn't the important factor.

~~~
pyre
But what if by walking faster you _improve_ the common factor? What if it's
just that gait speed is a symptom of poor heath, but by attempting to walk
faster (maybe even by going for more walks) you actually improve your health?

~~~
fragsworth
Unlikely. Or the effect might be minimal.

It's pretty common-sense that healthy people will already have a faster gait.
I mean for lots of people who are about to die, their gait speed is probably
zero because you can't even walk. Your average person doesn't even spend much
time exercising, and this study is about average folks, so it's saying that
average folks with a faster gait live longer. Most of them don't even
exercise.

~~~
herdrick
Exercise doesn't have to be intentional. I think this is probably partly
causal:
[https://news.ycombinator.com/item?id=5914630](https://news.ycombinator.com/item?id=5914630)

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harshpotatoes
So the question becomes, to how young a person does this apply? How far back
can be extrapolated? Is a slow 40something as meaningful a data point as a
slow 70something year old?

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sailfast
I could see this becoming an interesting metric for targeted health care or
health advertising, given the relative ease to determine gait speed from live
video feeds. "IF gait speed < X, change display ad to 'see an orthopedist'"

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bane
My father is nearing 80 and in the last couple of years his gait his stiffened
and slowed noticeably. Of course anybody has limited time left at 80, but it's
interesting how much _older_ he suddenly looked to an observer. 3 years ago he
was confused with men in their 60s.

I think he suddenly felt older to himself as well, this year my parents
finally decided to do a top-to-bottom review of their life-insurance, will and
other estate issues.

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HNJohnC
So the takeaway from this is if you find yourself in a nursing home you better
keep on trucking as fast as you can or the doctors will give up on you.

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lifeisstillgood
And thank you, colinprince, something that really does _stimulate_ my
intellectual curiousity, becoming a rarity on a front page that is starting to
re-confirm my intellectual stances.

Walking faster now.

~~~
ableal
I wonder if they were just punning on
[http://en.wikipedia.org/wiki/The_Quick_and_the_Dead_%28idiom...](http://en.wikipedia.org/wiki/The_Quick_and_the_Dead_%28idiom%29)

> Walking faster now.

Joke there, I suppose, since the authors did seem to find it applied for
diagnosis (poor health slows people down, news at 11 ...).

~~~
lifeisstillgood
Is it sad that my first thought before reading the article was the film with
Sharon Stone?

I think it might be more interpreted as "staying vital, keeps people alive"

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jb17
This reminds me of the following study, that had similar results but a better
title:

    
    
      How fast does the Grim Reaper walk? 
      http://www.bmj.com/content/343/bmj.d7679

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ecopoesis
It's good to see more data backing the "more active == longer life" anecdote.

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dctoedt
Obligatory xkcd link: [http://xkcd.com/552/](http://xkcd.com/552/)

(I have this one on a t-shirt.)

~~~
rgarrett88
[http://www.radiolab.org/2010/oct/08/](http://www.radiolab.org/2010/oct/08/)

Radio Lab did a segment on how a cities average gait can predict many things
about it.

