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THREAD: OK, @natesilver538 got mega-flamed abt this, & much of it was deserved (esp his baseless suggestion that PubHealth folks weren’t actively debating this issue). BUT, he raises a point abt “lesser” Risk Factors (RFs) worth thought/discussion.
1/ https://twitter.com/NateSilver538/status/1340361755403366400
1/ https://twitter.com/NateSilver538/status/1340361755403366400
1sr, these priority tiers for COVID vaccine were prelim/contested/evolving BUT they're NOT as nonsensical as they seem. (CAVEAT: I have deep expertise in Rx & screening prioritization across many conditions (CVD, DM, Cancers, etc) but have not worked on acute infectious Dx):
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http://1.It ’s right to note that those <45 w/ 1-2 of these lesser RFs are MUCH lower priorities than a 70y.o. w/o these RFs. Such folk should NOT be vaccinated early except for caretaking/occupational reasons.
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2. However, Life-Years (LYs), not just mortality risk, is generally considered an appropriate PubHealth target. My 55 y.o. pt w/ has MANY more LYs at risk than my most robust 75y.o pt, even w/o considering the quality of those LYs or consideration of equity/social costs.
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Silver's correct2note age is ByFar largest RF4COVID, but that’s also true4two leading causes of death -- CVD&Cancer. Yet, QALYs gained usually greatest4Rxing 55 y.o. w/ 2+ “lesser” RFs than for 75y.o. (Note, like COVID, “lesserRFs” R similarly not very substantive in young) /5
Why the U-shape? Why does late middle-age plus lesser RFs = highest net benefit even when age is ByFar greatest RF? In addition to the LY issue, most RFs are MULTIPLICATIVE, not additive, functions.
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Say 10yrs of age increases the odds of death by 1.5. Between ages 25 and 55 this compounding multiplicative function raises one’s risk from very low up to low-to-moderate. Then, the next 1.5 results in that much larger risk increase we see from age55 to age65.
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Well, lesser RF w/ OddsRatio of 1.5 (or 2 at 1.2) does SAME THING in that 55y.o.! It’s like moving you 10yrs up the age function. BINGO, as we say in science. (SideNote: Big medical advances in Rx of CVD&DM results in these RFs reducing life expectancy much IF good MedCare.)
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OK, Back2COVID. Unlike U-shape in NetBenefit seen4CVD Rx & Breast/Colon/Prostate CA screening, my back-of-the-envelope calc for COVID makes LYs gained somewhat greater in >65 than for 50-65y.o. (ageRF=bigger), but it’s much less than it looks when examining RFs in isolation
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In fact, Quality-adjustment & adding 2+ lesser RFs would prob reverse things, even w/o equity/social RoI considerations. Also realize that the age RF for hospitalization is much less than that for death, & the rate of post-COVID/ICU syndrome in younger folk is concerning.
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Final thoughts: Lesser RFs should NOT put those age <45 in a high vaccine priority tier, but prob should for those 50-65 w/ 2+ lesser or 1+ moderate RFs.
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When feasible, individual’s risk of contracting COVID and the difficulties/costs of socially isolating are important secondary considerations. Here I’m thinking abt my 50-65y.o. pts facing HUGE financial STRESS b/c they can’t work.
/fin
/fin
