
NYU: Obesity the biggest 'chronic' factor in New York’s Covid hospitalizations - onetimemanytime
https://www.zdnet.com/article/nyu-scientists-largest-u-s-study-of-covid-19-finds-obesity-the-single-biggest-factor-in-new-york-critical-cases/
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downerending
Here's the actual study:
[https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v...](https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v1)

ZDnet title seems a bit off, as first factor in their decision tree is _age_ ,
not _obesity_. Also, this doesn't appear to attempt to unwind causation vs
correlation. As I read it, it's just, _if you could only ask a few questions
to make your decision, what should you ask first?_ Useful for admitting, but
probably less so for understanding what's actually going on.

Looking at the numbers in the paper, high blood pressure, for example, seems
like a powerful predictor of problems. Presumably that's captured by the
obesity question, even though those two conditions are only partially
correlated.

Also interesting is that they don't see race as a factor. Other reports seem
to indicate that African Americans are doing significantly worse.

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mjthrowaway1
It’s worth noting their definition for obesity is BMI>40 as opposed to the
normal definition of BMI>30\. BMI>40 is considered “class 3” or “extreme”
obesity.

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ac29
In Table 1, BMI between 30 and 40 was also strongly correlated with hospital
admission: 659 people in that group were admitted, 256 were not.

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exabrial
[https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v...](https://www.medrxiv.org/content/10.1101/2020.04.08.20057794v1.full.pdf)

Surprising outcome: inconsistent data on smoking, they found no correlation.

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radford-neal
I looked at this question using the UK critical care data in a blog post at
[https://radfordneal.wordpress.com/2020/04/06/body-mass-
and-r...](https://radfordneal.wordpress.com/2020/04/06/body-mass-and-risk-
from-covid-19-and-influenza/)

From that data, it does indeed seem that having BMI>40 is a large risk factor
for COVID-19 being serious. BMI between 30 and 40 is also a risk factor, but
much less than for BMI>40.

In drawing these conclusions, I was assuming that being put in critical care
was a good proxy for serious disease, but it's obviously not perfect - those
who die quickly before reaching critical care obviously aren't counted, for
instance. I think this is probably not a big issue for the UK, but reports are
that quite substantial numbers of people in New York City died of COVID-19
without this being recognized by the health care system. Since we don't know
(from this study) what the BMI was for these people it's hard to draw
justified conclusions.

It's frustrating that they don't break down the BMI<30 category further, since
there's also reason to believe that low BMI could be a risk factor.

