Thread by @DrEricDing

I am devastated—I saw with my eyes what’s coming from CDC tomorrow. My sources told me on what their rationale is based. And based on what I know (epidemiologist for 20 years)—it is complete bullshit crafted on thin flimsy data. I can’t believe CDC has such incompetent leaders.🧵

2) what the CDC is doing is relaxing the guidelines of isolation to effectively ‘you can go out and have fun as long as you’re improving since yesterday’. Yes it’s ridiculous. Others have written on it. And it is totally public health abdication. newrepublic.com/article/179304…

3) but what are the hell are folks at the CDC thinking??? First of all, someone in CDC did a very basic short term state-level analysis of a certain unnamed states (you can guess which) that did the shitty policy early and look at the rough short term correlations. But covid had already peaked / peaking in the big state by the time the crap policy was enacted!!! Why is this junk? ….

4) Well if they base recs on a peak that is passing / has passed, then there would be little signal. In epidemiology, the “signal to noise” ratio matters to detect a signal over background noises in the data. Also if it based on mainly one major (mega) state— then any signals hard to see. Plus, third no signal seen if ALMOST NOBODY IN LAY PUBKIC HEARD THE POLICY in first place!

5) Now let’s talk about junk state level ECOLOGIC CORRELATIONS— when I first started my doctoral epidemiology program, I was warned by faculty mentors of a golden rule in epidemiology — never trust short term ecological studies. I was taught to almost never do state level epidemiology correlations because of their notorious unreliability in short term data for both reasons of ECOLOGIC FALLACY, CONFOUNDING bias, and junk NOISE NOISE NOISE!

6) What “Ecological fallacy”? Well it’s when you label a higher unit of analysis with the same label pretending people inside the group do the same thing — eg correlation analysis of “violent crime by state, versus condom / BC pill use frequency by state” — if you did such an analysis you would spuriously conclude that birth control use leads to violent crime, or crime leads to pill use” — it is not only CONFOUNDED, but you also ***don’t know*** that PILL USERS are the actual ones who committed the crime!!! Or in our case that just cuz a policy was quietly enacted in a mega state that anyone heard about it or actually did the thing the policy told them to. This is the ecologic fallacy of state level data—you don’t know who’s actually doing the thing.

7) Now about the other CONFOUNDING bias problem — as we all know US states are highly highly different from one another—a myriad of social cultural political and demographic difference between states. Whenever you do correlation analysis of them (especially in short term data), the correlation with “other factors” besides the X factor of interest can completely bias the results. Classic example is a study of people’s “condom use and household appliances” — very strong association - but does it mean using condoms will lead to spontaneous more toasters and TVs? Or buying TV sets will lead to more condom use? Of course not. Such a factor is confounded by other variables like wealth and education, etc. But that’s why STATE LEVEL analysis is very tricky - especially in short term data. I can try to statistically adjust for them, but in short term data it’s very unstable to do so in data. I’ve tried in my early career 20 years ago- got scolded by a trust faculty mentor (who is now a Dean of a major SPH) who told me never try to publish or base policies on state level analysis— short term CONFOUNDING AND ECOLOGIC FALLACIES renders them shoddy and unstable 99% of the time. Yet, this is what the new CDC guidelines are supposedly based on!!! Wtf. They fail Epidemiology 101!!!

8) According to sources, the data analysis is mainly based on change in COVID levels after a certain state announced & enacted a similar controversial isolation relaxation policy — on Jan 9th 2024!!! It’s a brand new policy after the Nov-Dec 2023 wave had already peaked! The peak is visible in the @BiobotAnalytics & CDC’s very own NWSS data. Thus using state data (see other major flaws above) for analyzing a policy enacted after the national wave has already peaked and hoping to find a signal above the noise of the immediate post-holiday season is ludicrous—especially with such short term data!!! Not finding any signal would be the expected default — which is what this kinda shoddy analysis is pre-destined to do! Again, what the holy hell @CDCgov.

Graph by @JPWeiland

9) Also, even worse—the enactment of this rule to relax isolation guidelines without any period of public comment is potentially illegal / inappropriate under California law. The @TheWHN will soon be filing a formal complaint that under CA legal framework- “Underground Regulations” - such a health guideline cannot be enacted without a period of public comment. We at the WHN will be posting a formal complaint to CA very shortly. Stay tuned. But hey, CDC will jump at the chance to use shoddy data based on shoddy enacted state level policy.

cdph.ca.gov/Programs/CID/D…

10) if you want to complain to the @CDCgov - then feel free to call the CDC tomorrow at [phone] and tell them how you really feel about their new supposed “health” guidelines. According to @jesseintl, the operator will record your email and then type up your complaint!

@CDCgov @jesseintl 11) Think about this— what if the CDC says - 📌‘NO NEED FOR CONDOMS ANYMORE IF YOUR HERPES OR SYPHILIS SYMPTOMS ARE IMPROVING SINCE YESTERDAY!!!’📌—because that is exactly the analogous policy the @CDCgov is now enacting with their new ‘to hell with it’ respiratory guidelines!

12) Oh, if you’re calling the CDC tomorrow to lodge your complaint — please direct complaints to these 3 key individuals 👇who are leading the media briefing.

Again, the toll free CDC phone number is [phone]. The operator is supposed to write down your email and then type up your complaint… and then send it up!

13) Furthermore — If you really want to tell Dr Mandy Cohen and Dr Demetre Daskalakis how you really feel… their business professional public LinkedIn profiles are below. Their message inboxes are open for messages too.




(After consulting with social media safety experts—expert confirm this is NOT considered doxxing because it is their self-declared public professional profiles. In fact, social media experts say that such self-declared LinkedIn is a valid public feedback medium).linkedin.com/in/demetre-das…
linkedin.com/in/mandy-cohen…

14) Remember the outrage when last CDC director said this in Dec 2021? “We shortened the time to encourage people to do the right thing”—when CDC halved the recommended COVID isolation period from 10 to 5 days—already dubious. But today’s lunacy is worse.

15) BREAKING--We have filed a legal complaint against California Dept of Public Health and Cal OSHA regarding their isolation guideline drop--the impetus and data behind the CDC's new isolation rule drop. the CA rule was illegally enacted--thus invalid!

16) CONFIRMATION... precisely as I said yesterday-- CDC based their new rule from shoddy data from California -- which again was enacted, checks notes... only on Jan 9th 2024 after the peak had passed! (see above why this is bullshit). I hate being right. but hopefully we can get CA to realize their rule was illegally enacted and force it back...

17) Clear as mud… the new CDC isolation guidelines were written to be as vague as possible — it’s the stuff of corporate lobbyists’ dreams…