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Deadly heart attacks are more common on a Monday

(www.bhf.org.uk)
239 points giuliomagnifico | 2 comments | 06 Jun 23 13:19 UTC | HN request time: 0.41s | source
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barbegal ◴[06 Jun 23 14:15 UTC] No.36213140[source]▶
The headline is misleading. The actual study proved that the recorded date of admission to hospital in Ireland with ST-segment elevation myocardial infarction was increased on a Sunday and Monday. Increased admissions on a Monday is not that unusual given that people often seek medical attention after the weekend but maybe more surprising is the increase on a Sunday. https://heart.bmj.com/content/109/Suppl_3/A78
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haldujai ◴[06 Jun 23 14:22 UTC] No.36213241[source]▶
From the methods section of the abstract: “We excluded post-fibrinolysis patients, patients with old stents, and those who presented more than 24 hours after the onset of pain.”[edit: I misread the PDF version which included multiple abstracts, the methods I’m referring to was from a separate study with the title cutoff, this specific abstract didn’t specify. But from below and table 1 in: https://jamanetwork.com/journals/jama/article-abstract/20140... which looked at 68,000 STEMIs, 3.1% presented > 12 hours and 8.4% had an unknown time of symptom onset. Wouldn’t explain the magnitude of effect seen in this study. Circadian effects on STEMI and increased incidence on Monday are not new observations.]

Don’t think late presentation STEMIs are that common to begin with for your argument to have logical sense, this is the worst form of a “heart attack”.

From this single center study presentations > 12 hours only comprised 10%.

https://www.ingentaconnect.com/content/wk/jcarm/2017/0000001...

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tgv ◴[06 Jun 23 16:14 UTC] No.36215022[source]▶
What is the effect in this study? The linked article has no info, not even the doi.
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OJFord ◴[06 Jun 23 16:47 UTC] No.36215613[source]▶
I linked it in another comment, but that's now a flag-hidden thread, so: https://heart.bmj.com/content/109/Suppl_3/A78.abstract
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1. tgv ◴[06 Jun 23 18:52 UTC] No.36217393[source]▶
Thanks for the link. I'm not impressed by the effect at first sight. I certainly wouldn't want to exclude anything based on it. I mean, it's 13% more on Monday, which makes it "significant", but if you subtract the 3.1% you mention, you get close to the Sunday fraction, which isn't significant (p>0.05, which is a lousy statistic anyway). While it looks there's something going on, it's not enough to ignore the effects of data manipulation.
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2. haldujai ◴[06 Jun 23 21:33 UTC] No.36219383[source]▶
You're assuming that the 3.1% for > 12 hours is different between weekdays and weekends. While the study you're quoting grouped after-hours with weekends there were less delayed presentations in this subgroup compared to the M-F business hours group.

Other weekday numbers will also have delayed presentations included so you can't just "subtract 3.1" from one day and declare statistical insignificance.

What you can do is subtract it from every day as we know that 97% of STEMIs present within 12 hours.

As this is just an abstract we don't know what the authors did in this particular example but it's not the first study to suggest Mondays have the highest ACS rates.