
Day of week of procedure and 30 day mortality for elective surgery (2013) - stanislavb
https://www.bmj.com/content/346/bmj.f2424
======
savagedata
> Choosing Monday for a surgery increases your chance of success 2 times

The title seems poorly worded. The researchers studied mortality rate, not
success of procedures. Since these were elective surgeries, I assume the
success rate was high. If your surgery has a baseline success rate of 90%,
what would it mean to increase that 2 times?

The conclusion of the study was instead that the odds of death were 44% higher
on Friday compared to Monday, and 82% higher on the weekend compared to
Monday. Basically, there was a gradual increase in the odds of death from
Monday to Thursday, but a big jump up on Friday and again on the weekend.

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glofish
Almost certainly the selection bias plays a major role - surgeries done early
in a week are different than those scheduled later in the week.

~~~
mabbo
Yeah, this reminds me a lot of the "Impossibly Hungry Judges" problem[0].

[0] [http://nautil.us/blog/impossibly-hungry-
judges](http://nautil.us/blog/impossibly-hungry-judges)

~~~
samatman
> _If hunger had an effect on our mental resources of this magnitude, our
> society would fall into minor chaos every day at 11:45 a.m._

...this has potential!

Scrape GitHub, find closed issues marked 'bug', do a blame on the offending
line or lines, find the timestamp and plot.

~~~
tmpz22
It would be a pita to control for time zones, or even culturally different
lunch times and eating habits

~~~
JoshTriplett
Git commits do embed a timezone in the commit timestamp. And while lunchtime
will vary by person, there may still be a visible effect around common
lunchtimes over a large number of people.

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awinter-py
uhh guessing it halves the % of failures is what they actually mean

30k deaths / 4 million procedures is 0.75% death rate

going from 99.25% to 99.6% survival isn't doubling anything

also 'success' doesn't appear anywhere in this article, guessing '30 day
mortality' is the thing they're measuring

~~~
phkahler
Yeah that's the main reason i had to read it. Even if you got to 100 percent
on Monday that would imply only 50 percent success on other days. Nobody would
have an elective procedure with that low success rate.

~~~
lrem
Success rates are often not that high. Also depends on the exact definition of
success. Say for carpal tunnel, from that I've read, the "there was any
improvement" success rate is about 90%, but the "fully healed" success rate is
as low as 15%.

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gojomo
While I recognize it's an attempt to highlight the "takeaway", the submission
title (currently "Choosing Monday for a surgery increases your chance of
success 2 times") seriously distorts the actual study contents.

It's not analyzing "success" of the surgery, but "30-day mortality for
(almost) any cause". (While death caused by the surgery is definitely failure,
the absence of death isn't necessarilt "success".)

Also, there's no evaluation of "consciously choosing Monday" as a causal
factor. There could be all sorts of pressures causing the surgeries on
different days-of-the-week to have different risk factors, even if they're all
"elective". (As they note: "One of the weaknesses of using administrative data
is that we were unable to completely adjust for inherent selection biases that
probably exist for elective procedures that are scheduled on weekends.".)

I can believe there's some effect of patient choice, possibly related to staff
exhaustion, post-op complications happening during under-resourced weekends,
but expect a lot of the effect found here to be due to factors pushing certain
surgeries/deaths into certain days (and arbitrary categories that might have
affected inclusion).

~~~
dang
Submitted title was "Choosing Monday for a surgery increases your chance of
success 2 times". That breaks the site guidelines, which say: " _Please use
the original title, unless it is misleading or linkbait; don 't
editorialize._"

[https://news.ycombinator.com/newsguidelines.html](https://news.ycombinator.com/newsguidelines.html)

Cherry-picking the detail you think is most important from an article is a
form of editorializing. If you want to say what you think is important about
an article, please post it as a comment to the thread. Then your view will be
on a level playing field with everyone else's.

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flyGuyOnTheSly
I'd believe it.

Rushed to the hospital on a Saturday night when my father in law suffered a
massive heart attack... and he was held stable for almost 2 hours before a
surgeon capable of working the situation was able to make it in and insert a
stent.

It seemed strange to me that a hospital would have a schedule like that...
where most doctors work 9 to 5 monday to friday, and most everybody goes home
for the weekends.

People can fall ill at any time. Although I suppose the majority of people
would only notice that they were ill and come into the hospital during regular
business hours.

I noticed this because he was in an induced coma for a few weeks.

At night they lock the place up so tight there is literally only one door in
the emergency room that is open to the outside. Something about them being
worried about narcotics thefts.

That was a frustrating learning experience our first evening in the hospital,
I tell you!

Thankfully he pulled through with flying colors!

~~~
nraynaud
I think you missed the word "elective", I guess the whole point was to remove
emergency surgery from the study.

~~~
Consultant32452
I think the principal is still the same. Surgeons do not perform surgeries
every day. They usually have some days of the week they meet with their
patients in an office setting. And then other days of the week they are in
back to back surgery all day. It would be interesting to know what, if any,
industry standards determine which days are allocated for which. Or if there
is a hierarchy of surgeons who get "dibs" on scheduling their surgeries on
Mondays.

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dehrmann
I can't find a source, but 70's-era wisdom I got from my grandfather was when
buying an American car, buy one assembled on a Tuesday. People are hungover on
Monday, Tuesday is their best work day, it's downhill on Wednesday and
Thursday, and they're checked out on Friday.

~~~
tcoff91
How can you possibly figure out when a car was assembled?

~~~
Consultant32452
The sticker on the door jam with the VIN usually has the month and year.

The VIN has an indicator for which factory it was built in. You may find
rumors/wisdom/witchcraft around one factory having better quality controls
compared to another.

Which day of the week your car was "Manufactured" probably isn't a thing that
even makes sense. That's just going to be final assembly. Each individual part
will of course been manufactured on a different day. Even if you believed the
magic of Tuesday is the best day, do you want to know the day your doors were
hung on the hinges, or the day the pistons were machined?

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univalent
Pro tip: if getting a colonoscopy, always always get the first appointment of
the day. I work in med devices and ummm those scopes still have poop left over
between procedures. Its not harmful, but still...

~~~
technofiend
I'm no expert but aren't you exposing one patient to the previous patient's
poop? There could be anything from a lovely c-diff payload to something the
next guy is allegeric to like nuts. As a layperson it hardly seems harmless.

~~~
Defenestresque
I have a feeling OP means they are sterilized or autoclaved but some (now non-
dangerous) particles remain as there is no medical point in _thoroughly_
cleaning them after sterilization. Which would make sense.

~~~
Frost1x
People get a bit paranoid about how "clean" things are. I for one am not as
concerned about how "clean" something looks but how potentially harmful it is
to my livelihood. Looks can be deceiving, either way, without considering the
entire situation.

Something that looks unclean can be sterile and harmless while something
sterile and visually clean can be incredibly harmful as well (e.g. water with
certain toxins or compounds).

------
jeffdavis
A mortality rate of 0.7% for elective procedures sounds high. What counts as
elective but carries such risk? Is it similar in other countries?

~~~
bosie
They aren't measuring the mortality rate of the procedure. they are measuring
this:

"Death in or out of hospital within 30 days of the procedure."

If I am already on my death bed (for lack of better word), the procedure's
mortality rate is probably not swaying it much. Also, couldn't find if they
would include something like a lethal car accident 28 days after the procedure
or not.

> An elective procedure was defined as “elective: from waiting list,”
> “elective: booked,” or “elective: planned”

High risk procedures seem to be cancer related and specific excisions.

~~~
tomrod
If one uses an "episode of care" framework, mortality within 30 days of
treatment is a standard metric.

[https://www.cms.gov/Medicare/Medicare-Fee-for-Service-
Paymen...](https://www.cms.gov/Medicare/Medicare-Fee-for-Service-
Payment/PhysicianFeedbackProgram/Episode-Costs-and-Medicare-Episode-Grouper)

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atlasunshrugged
Are there any other interesting things like this that people know of? I guess
you could consider them advanced life hacks in a way.

One things I was thinking of is trying to schedule meetings right after lunch.
I'm basing this on the research of judges being more lenient after lunch.
[https://www.theguardian.com/law/2011/apr/11/judges-
lenient-b...](https://www.theguardian.com/law/2011/apr/11/judges-lenient-
break)

~~~
grepfru_it
I have always scheduled job interviews in the morning because the hiring
manager is more alert and (I read somewhere) in a more upbeat mood before
having to deal with tragedies of work. I extended this later in life to making
sales calls as the first thing I do in the morning because _I_ am more awake
and alert.

Switched on its head, I prefer morning interviews because I can really focus
on the candidates without thinking of (or being annoyed for stopping work on)
a deep problem I began working on. If a sales person calls me in the morning,
I'm more likely to answer and have a conversation.

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qrbLPHiKpiux
This is why I only work 3 days a week.

The stuff I do really taxes my mind and there is no way I would be able to do
it well any more than that.

Monday’s Tuesday, and Thursday.

Still, patients complain.

Go elsewhere.

------
neiman
I'd rephrase the submission title to 'choosing the first working day of the
week for a surgery doubles your chance of success"

In the US it is Monday as in the title, but in other countries, Israel for
example, it would be Sunday.

~~~
abrichr
The study was done in England. Unfortunately the results can't be generalized
to the rest of the world.

------
gmanontherocks
If a doctor tells you to get a Tonsillectomy on Sunday, don't push back too
hard. Get the Tonsillectomy. You probably really need it.

I expect this is a large portion of the effect that this study is measuring.

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freepor
It’s for the exact same reason that you deploy code on a Monday... if
something gets fucked you have a week to stabilize it before the pager crew
takes over.

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cryptica
Maybe it's because surgeons on average tend to put off more difficult
surgeries to a later day in the week. They don't want to come into the
operating theater after a weekend of hard drinking and have to do a complex
brain operation on Monday morning.

So they will organize their schedule so that they only do routine low-risk
operations on Mondays.

~~~
metanonsense
I don't know. "No change on Friday" also sounds like a reasonable rule when it
comes to essential parts of the human body.

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thewizardofaus
Reminds me of a study they did for... chance to get parole approved based on
time of day. Findings were early in morning and after lunch breaks was the
most successful time. Just before clock-off and lunch inmates chances were
reduced.

~~~
RubberSoul
The effects reported in that study are probably not real [0, 1].

[0]: [http://nautil.us/blog/impossibly-hungry-
judges](http://nautil.us/blog/impossibly-hungry-judges)

[1]:
[http://journal.sjdm.org/16/16823/jdm16823.html](http://journal.sjdm.org/16/16823/jdm16823.html)

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xhkkffbf
What about during football season? Doctors and nurses are pretty serious
folks, but I can see them having a few too many during the exciting football
games. Not all of them, of course, but some like the games.

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DamnInteresting
Perhaps (2013) should be added to the title.

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bentona
I wonder if posting this on Saturday was intentional, and if it has any
outcome on its success on hn:)

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Rerarom
My last two surgeries were done by a doctor who only had Wednesday as a day
for surgeries.

