Impact of masks in schools

[Anonymous]

https://www.cdc.gov/mmwr/volumes/71/wr/pdfs/mm7110e1-H.pdf

New study on impacts of masks in schools

‘ In Arkansas during August–October 2021, districts with universal mask requirements had a 23% lower incidence of COVID-19 among staff members and students compared with districts without mask requirements.’

‘Among districts that switched from no mask requirement to any mask requirement (full or partial), incidence among students and staff members decreased by 479.7 per 100,000 (p<0.01) upon implementation of the mask policy. In areas with high COVID-19 community levels, masks are an important part of a multicomponent prevention strategy in K–12 settings (5)

[Anonymous]

Ok but 23% of 0 is still 0

[Anonymous]

Anonymous wrote:Ok but 23% of 0 is still 0

In what world did zero people get COVID over the last two years?

[Anonymous]

Not a randomized controlled study. Drops in cases happen for a lot of reasons. That being said, if these results are due to masking, it's a great reason to institute mask mandates when case rates are high.

[Anonymous]

It’s definitely important to wear a mask in Arkansas! Such a gross state filled with stupid, gross people.

[Anonymous]

Did they control for other mitigation measures in those communities? Mask mandates usually go with distancing, masking st stores, etc.

[Anonymous]

Anonymous wrote:Did they control for other mitigation measures in those communities? Mask mandates usually go with distancing, masking st stores, etc.

Yup and communities who accepted mask mandates probably had a greater proportion of people who stayed home and limited social interactions.

[Anonymous]

Anonymous wrote:

Anonymous wrote:Did they control for other mitigation measures in those communities? Mask mandates usually go with distancing, masking st stores, etc.

Yup and communities who accepted mask mandates probably had a greater proportion of people who stayed home and limited social interactions.

DP. But communities do not exist on vacuums. It’s not like there is no overlap between them. Some people on the masks required communities were probably relaxed about Covid, and some on mask optional communities were likely very careful (perhaps more so since their kids weren’t masking at school). The boundaries between communities are fluid and people move back amd forth between them for all sorts of reasons.

I fully appreciate that this is a correlational study and must be regarded as such. But I’m not sure this is as big a driver of the results as some may think.

[Anonymous]

I don’t think 23% reduction is enough to justify mandates.

[Anonymous]

Even if we set confounding variables aside, a 23% drop in cases is significant, but not really a game changer- particularly when cases are moderately low. It slows the spread a bit, but certainly doesn’t stop it. I find it odd when people say that it is safe for themselves or their child to go to school when universal masking is in place, but it suddenly becomes unsafe when masks are optional. Yes, the available data suggests an increased risk, but the level of increased risk isn’t significant enough that it would typically change rational behavior.

What I find most interesting in that study is Figure 2. To some extent, you can interpret it as evidence that the 23% reduction is not merely the result of confounding variables in the communities (you don’t really know that for certain, but I find it moderately compelling). However, the downward trend in cases in schools while leading up to mandate, without a corresponding decrease in community cases over the same time period, suggests there are other factors that are having a significant impact besides masking.

[Anonymous]

It’s ARKANSAS, so many fewer of them were vaccinated! Cannot compare to here.

[Anonymous]

Yet in Spain, they saw no difference. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4046809

Background: Mandatory use of face covering masks (FCM) had been established for children aged six and above in Catalonia (Spain), as one of the non-pharmaceutical interventions aimed at mitigating SARS-CoV-2 transmission within schools. To date, the effectiveness of this mandate has not been well established. The quasi-experimental comparison between 5 year-old children, as a control group, and 6 year-old children, as an interventional group, provides us with the appropriate research conditions for addressing this issue.

Methods: We performed a retrospective population-based study among 599,314 children aged 3 to 11 years attending preschool (3-5 years, without FCM mandate) and primary education (6-11 years, with FCM mandate) with the aim of calculating the incidence of SARS-CoV-2, secondary attack rates (SAR) and the effective reproductive number (R*) for each grade during the first trimester of the 2021-2022 academic year, and analysing the differences between 5-year-old, without FCM, and 6 year-old children, with FCM.

Findings: SARS-CoV-2 incidence was significantly lower in preschool than in primary education, and an age-dependent trend was observed. Children aged 3 and 4 showed lower outcomes for all the analysed epidemiological variables, while children aged 11 had the higher values. Six-year-old children showed higher incidence than 5 year-olds (3•54% vs 3•1%; OR: 1•15 [95%CI: 1•08-1•22]) and slightly lower but not statistically significant SAR and R*: SAR were 4•36% in 6 year-old children, and 4•59% in 5 year-old (IRR: 0•96 [95%CI: 0•82-1•11]); and R* was 0•9 and 0•93 (OR: 0•96 [95%CI: 0•87-1•09]), respectively.

Interpretation: FCM mandates in schools were not associated with lower SARS-CoV-2 incidence or transmission, suggesting that this intervention was not effective. Instead, age-dependency was the most important factor in explaining the transmission risk for children attending school.

[Anonymous]

For the MMR piece, I'm trying to find the underlying incidence. They report the community incidence at 745/100,000, declining to 137/100,000.

My point is that if you've got a really low incidence, a 23% decline from a really low incidence could be really not meaningful.

[Anonymous]

Anonymous wrote:It’s ARKANSAS, so many fewer of them were vaccinated! Cannot compare to here.

They state that vaccination rates at the time of study were 13-18%. So yeah, not high.

[Anonymous]

These studies are pointless. No one should care about cases, long covid is so overblown it’s practically absurd. The issue is severity of disease and so vaccine rates of the community is the big difference maker. We don’t need studies for this as all of Europe has been unmasking their kids (and especially primary age) the entire pandemic. Kids can continue to wear high quality masks if they choose.