
Lack of sleep increases stroke risk - aginn
http://www.usatoday.com/news/health/story/2012-06-11/sleep-stroke-risk/55506530/1
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3pt14159
Be very wary of headlines like this. They draw the line at 6 hours, but that
includes everyone, even people that only get 3 hours. What we want is the raw
curves. If you get exactly 5 hours and 55 minutes a night, you might only be
1.5 times as likely as someone who gets 9 hours a night, while the people
getting 4 hours a night are 15 times more likely.

~~~
dredmorbius
What you want to see is the study, how the analysis variables were
constructed, and what models were tested.

If a simple binary "subject slept 6 hours or fewer" variable is constructed,
and there's no other discriminant, then _if_ there is a significant positive
correlation, it will show.

Testing multiple conditions, exclusively (3 or fewer, 4 or fewer, 5 ..., etc.)
would get around this.

By way of comparison: I've used the Harris-Benedict basal metabolic rate
formula to estimate caloric expenditure by individuals. The question came up:
how well does this scale to extreme weights. It turns out that the original
study is online as a PDF, including full stats on all the study subjects. My
surprises were that 1) the formula is a lot older than I'd imagined (dating to
1919), involved a relatively small study size (a few score participants), and
the weight range did _not_ include high-end extremes unfortunately rather too
common in current populations. I've taken to treating the values generated for
extremely overweight individuals with a bit more suspicion as a result.

Study context _matters_.

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genwin
If one sleeps less than 6 hours a night, maybe there's other reasons for that,
that lead to stroke, like anxiety over being deep in debt. So reducing such
risk of stroke may not be as simple as getting more sleep.

Reminds me of the study that concluded that people living together (vs.
married) leads to ~30% greater chance of alcholism. Maybe alcoholics just
aren't as likely to get married?

Surely there's a Wiki on this type of logical fallacy somewhere. Anyone know
what it's called?

~~~
davej
Perhaps 'Correlation does not imply causation'. The associated logical fallacy
is known 'Post hoc ergo propter hoc'.

[http://en.wikipedia.org/wiki/Correlation_does_not_imply_caus...](http://en.wikipedia.org/wiki/Correlation_does_not_imply_causation)

<http://en.wikipedia.org/wiki/Post_hoc_ergo_propter_hoc>

~~~
genwin
Great, I'll know now. I see a lot of such conclusions in major media. Wish
they'd point out the fallacy, but that probably wouldn't sell the news as
well!

Love the example in the 2nd link: 'One class of examples is sometimes called
the "Rooster Syndrome": "believing that the rooster’s crowing causes the sun
to rise".'

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skore
I think the actual correlation here is:

Sleeping very little -indicates-> Stress and Anxiety -builds to-> Hypertension
-leads to-> Stroke

Major disturbances in sleeping habits - Insomnia or Excessive Sleeping - are
themselves strongly indicative of Depression, another major marker in terms of
the Anxiety->Hypertension->Stroke vector.

So, to conclude: Yes, sleeping very little is probably correlated with health
problems, but mostly because it indicates something else being very wrong.

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jlarocco
I wish they gave more information.

Is the effect reversible? How long does it take for a persons stroke risk to
go back to normal if they start sleeping more? What if I get 5 hours of sleep
five nights a week, but 10 hours each of the other two nights?

~~~
corin_
It's a case of wishing they had more, not gave more, information - or more
accurately, wishing they will keep going to get this information.

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aginn
More reason why to sleep more

[http://www.aginnt.com/post/23693419818/how-to-be-a-great-
ent...](http://www.aginnt.com/post/23693419818/how-to-be-a-great-entrepreneur-
sleep-breaks-and-a#.T9judyu-RrU)

~~~
hobin
More reasons why both 'SLEEP MOAR!' and 'SLEEP LESS!' are misguided:
<http://ukpmc.ac.uk/abstract/MED/12698511>

~~~
aginn
It does depend on what you need, but in general, not sure many people
recommend to sleep less. I thought the world suffers from overload. The number
of hours we sleep has fallen.

I think the best sleeping habits reflect those of Churchill and humans before
the 19th century: sleep 6 hours and then sleep 2 to 4 in the middle of the
day.

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akozak
A more balanced take on the study:
<http://www.medpagetoday.com/MeetingCoverage/APSS/33225>

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munkydung
I guess all parents of small children are doomed? sensational headline is
sensational.

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scottchin
There doesnt seem to be any links to the study itself...

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cwhittle
<http://www.regardsstudy.org/>

Doesn't appear to be published yet, just presented at the SLEEP2012
conference.

Ruiter M, Howard VJ, Letter AJ, Kleindorfer D. Short sleep predicts stroke
symptoms in persons of normal weight. SLEEP 2012; June 11, 2012; Boston, MA.
Abstract 0829.

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adventureful
Eat a terrible diet, get little exercise, live a sedentary lifestyle, approx.
997 times more likely to have a stroke.

~~~
khyryk
Sounds like the stereotypical coder.

