CDC accused of 'file drawering' a study that found student masking DID NOT 'have a statistically significant benefit'

New York Magazine is burying the lede here. The “study suggesting no clear benefit from school mask mandates” for children was one done by — wait for it — the CDC:

A study suggesting no clear benefit from school mask mandates has many experts questioning the policy https://t.co/1wM1Y2q3dc

— New York Magazine (@NYMag) August 20, 2021

Here’s the opener:

At the end of May, the Centers for Disease Control and Prevention published a notable, yet mostly ignored, large-scale study of COVID transmission in American schools. A few major news outlets covered its release by briefly reiterating the study’s summary: that masking then-unvaccinated teachers and improving ventilation with more fresh air were associated with a lower incidence of the virus in schools. Those are common-sense measures, and the fact that they seem to work is reassuring but not surprising. Other findings of equal importance in the study, however, were absent from the summary and not widely reported. These findings cast doubt on the impact of many of the most common mitigation measures in American schools. Distancing, hybrid models, classroom barriers, HEPA filters, and, most notably, requiring student masking were each found to not have a statistically significant benefit. In other words, these measures could not be said to be effective.

It also looks like the CDC intentionally buried the result on student masking by not putting this information in the summary of the study, a practice called “file drawering”:

Scientists I spoke with believe that the decision not to include the null effects of a student masking requirement (and distancing, hybrid models, etc.) in the summary amounted to “file drawering” these findings, a term researchers use for the practice of burying studies that don’t produce statistically significant results. “That a masking requirement of students failed to show independent benefit is a finding of consequence and great interest,” says Vinay Prasad, an associate professor in University of California, San Francisco’s Department of Epidemiology and Biostatistics. “It should have been included in the summary.” “The summary gives the impression that only masking of staff was studied,” says Tracy Hoeg, an epidemiologist and the senior author of a separate CDC study on COVID-19 transmission in schools, “when in reality there was this additional important detection about a student-masking requirement not having a statistical impact.”

A 3,000 word deep dive into the evidence behind student mask mandates

Many countries around the world – with vax rates, case rates, and mortality above and below the US – do not require masks on students. Why does the US?

My latest for @NYMag https://t.co/r2nYIHVPNj

— David Zweig (@davidzweig) August 20, 2021

From the article:

"Many of America’s peer nations around the world — including the U.K., Ireland, all of Scandinavia, France, the Netherlands, Switzerland, and Italy — have exempted kids, with varying age cutoffs, from wearing masks in classrooms." https://t.co/kYoEkjq1FE

— Matt Welch (@MattWelch) August 20, 2021

But it’s not just this CDC study. There are no studies that Zwieg — or anyone — can find that “show conclusively that kids wearing masks in schools has any effect on their own morbidity or mortality or on hospitalization or death rate in the community around them”:

“I’m not aware of any studies that show conclusively that kids wearing masks in schools has any effect on their own morbidity or mortality or on the hospitalization or death rate in the community around them.”

⁦@davidzweig⁩ https://t.co/pCut7MCfhX

— Jennifer Sey (@JenniferSey) August 20, 2021

One glaring deficit on all of the studies is that they don’t look “at mask use in isolation from other mitigation measures, or against a control”:

“I reviewed 17 different studies cited by the CDC in its K-12 guidance as evidence that masks on students are effective, and not one study looked at student mask use in isolation from other mitigation measures, or against a control.” https://t.co/9Lr7JsfUUg

— Josh Kraushaar (@HotlineJosh) August 20, 2021

But, alas, this is what the CDC is recommending:

This article raises serious questions about masking for preschool kids aged 2-5:

“Reading faces is critical for social emotional learning. And all children are actively learning language the first 5 years of life, for which seeing faces is foundational” https://t.co/9Lr7JsfUUg

— Josh Kraushaar (@HotlineJosh) August 20, 2021

What they did find is that adult mask use and vaccination does work:

Critical point:

“Our most effective way of protecting everyone, students and school staff alike, is by vaccinating the adults around them,” https://t.co/9Lr7JsfUUg

— Josh Kraushaar (@HotlineJosh) August 20, 2021

And:

“Pediatric infection rates right now vary wildly, correlating with how many adults in their area are vaccinated. Evidence suggests staff-to-staff transmission is more common than transmission from students to staff, staff to student, or student to student” https://t.co/9Lr7JsfUUg

— Josh Kraushaar (@HotlineJosh) August 20, 2021

Oh, and the terrifying part? None of the experts Zweig talked do can give him an end date when we’ll ditch the masks:

So many people seem to think the masking of kids is temporary. Listen to what they're saying. There's nothing temporary about it. https://t.co/3y4KLF6wf8 Thank you for this excellent piece, @davidzweig. pic.twitter.com/apOCBHNNsx

— Karol Markowicz (@karol) August 20, 2021

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