Thread by @jeremyfaust

Do I support masks?

Yes.

Mask wearing is an important component of a suite of things we can do to stop coronavirus.

Does this paper earn its title?
Do their data justify the conclusions?

No.

I just don’t see it.

And why has no one noticed this?

pnas.org/content/early/…

My major concerns are (so far):

1. Likely incorrect denominator (case counts in the US are woefully inaccurate).

If we base case counts solely on reported cases how do we account for under testing? For changes in testing behavior. For who is getting tested?

2. Likely incorrect time periods used for regression. The authors confuse the official enacting of policy with start of a behavior; mask wearing does not occur the same day as a policy goes into effect!

Show me uptake!

Show me uptake isn’t simultaneous to adopting other things!

Before I move on;

Those vertical lines they drew for the regressions.

It looks to me as though the direction and magnitude of the regression trends appears to depend GREATLY on where the lines are drawn.

Lines reflecting when mask wearing actually went up could change result!

3. This paper totally fails to account for contribution of other behaviors that like co-migrate with mask wearing.

Mask wearing liekly correlates to other behaviors that demonstrate that society “gets it.”

That shows what we do collectively matters.

NOT AIRBORNE TRANSMISSION!

4. This paper has a complete absence of discussion section to address any of this.

Doesn’t that bother anyone?

Thus...

5. There is a bold, inadequately tempered "conclusion" regarding airborne transmission based on these rather thin data that may or may not have anything to DO with airborne transmission effecting case counts.

What China did is used as a comparison.

China indeed had better mask wearing.

THEY ALSO SHUT DOWN FOR TWO MONTHS, PEOPLE.

We barely hacked 40 in many places!

These are my 10,000 foot view impressions.

I await #epitwitter to chime in.

But we can NOT promote papers that confirm our bias and beliefs when the modest data presented do not match the rather grandiose proclamations of the conclusions.

If we do that, we have no defense against those who present equally ambiguous data and who also jump to conclusions that are unjustified — and possibly dangerous ones (unlike this one; though inducing fear is a danger too, we must remember).

If we do what’s happening today...if we promote papers we have not scrutinized...and later those papers are undermined by better data or valid critiques...

we look bad for promoting so-so science as far closer to “settled” than it is.

We spend clout.

We suffer for it.

This paper does NOT establish that coronavirus mainly is spread by airborne transmission.

That may be true.

But it certainly may NOT be.

The needle has not moved for me, based on this.

The TITLE should be retracted.

A discussion section (totally absent!) should be ADDED.

I’m wearing my mask in the meantime, yes.

It is a cue to remind me about other equally important behaviors.

And mask wearing likely helps stop some spread in some situations.

Who knows to what extent.

Probably “a little bit, all the time” and “sometimes a lot.”

But this packaging of science does NOT help make that case.

It might weaken it, if sufficiently undermined and we were busy touting it as The Proof.

Our credibility is not endless.

What a paper concludes is important.

How it gets there matters, though.

So agreeing with the conclusion should not mean turning your brain off before reading the paper.

That’ll burn you, I promise.

If not in this instance, then later.

Read the papers.

Promote the science.

Keep learning together.
/fin