THREAD: Lots of alarm over the https://abs.twimg.com/emoji/v2/... draggable="false" alt="🚨" title="Police cars revolving light" aria-label="Emoji: Police cars revolving light">88% Mortalityhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="🚨" title="Police cars revolving light" aria-label="Emoji: Police cars revolving light">among #Covid19 patients on ventilators. The paper *should* say "Among pts on vents, mortality will range from 25-97%". This @JAMA_current study is a great for a JournalClub on "Beware Your Denominator"https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">(1/7)
https://jamanetwork.com/journals/jama/fullarticle/2765184">https://jamanetwork.com/journals/... https://twitter.com/DrEricDing/status/1253232915158310912">https://twitter.com/DrEricDin...

Now, I know that the abstract say "Mortality for those requiring mechanical ventilation was 88.1%." And I know it& #39;s @JAMA_current, so it has to be perfect, right? But its very, VERY misleading in the headlines on @CNN @business @medpagetoday & tweets by MDs, here& #39;s why...(2/7)

Here& #39;s the key: Median follow-up time to death or discharge = 4.4d (IQR 2.2-9.3), median follow-up at time of censoring = 4.5d (2.4-8.1). That& #39;s simply not enough time to say something useful about ventilated pt w/ #Covid19. More than 72% of their sample was excluded. Lookhttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">(3/x)

Look at Table 5. First it& #39;s amazing to see a paper w/ >1,100 vented #Covid19 pts. But of these 1151 vented pts, *at a median follow-up time of 4.5d* only 38 went home, 282 died, while 831 were still hospitalized. 282/(38+282) = 88% mortality. But thats *quite* misleadinghttps://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">(4/x)

A better conclusion?
- "Among the 1,151 pts who were mechanically ventilated, at a median follow up of 4.5 days, 3% had gone home, 25% had died, & 72% were still in the hospital".
- "The eventual mortaily rate will thus range between 25% (282/1151) and 97% (1113/1151)." https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">(5/7)

Still alarming, sure. But to put those numbers in context, let& #39;s remember that good ole fashioned ARDS has pretty frightening mortality. For mild, mod, severe ARDS the mortality is around 25%, 35%, 45%. Its likely *much* higher in ARDS from #Covid19, but we don& #39;t know yet.https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index">(6/7)

The rapid publication cycle of #Covid19 = lots of data misinterpretation. The @JAMA_current paper put all of the data out there. But that eye-popping 88% # in the abstract is too easy to misinterpret. The #s are scary, but they should be presented & reported more clearly (7/7)

@threadreaderapp unroll

Link to actual paper fell off: https://jamanetwork.com/journals/jama/fullarticle/2765184?guestAccessKey=6ad3f237-3962-483e-9a30-81ef5ad2c40f&utm_source=silverchair&utm_medium=email&utm_campaign=article_alert-jama&utm_content=olf&utm_term=042220">https://jamanetwork.com/journals/...

A clarification that others have pointed out (thx peers). Not sure # specific to vents but:
- LOS for pts dc& #39;ed alive home: 3.9d (2.4-6.7)
- LOS for pts who died: 4.8d (2.3-7.4)
- LOS for pts inhospital at study endpoint: 4.5d (2.4-8.1)
- median post-dc follow-up: 4.4d (2.2-9.3)

Also, to be very clear, the authors are forthwright about the risk of bias in the limitations. But writers of newspaper headlines dont always read the limitations. "3% discharged, 25% dead, & 72% still inpatient" is more representative. Most ARDS studies report 28-60d mortality.