Systematic review finds child mask mandates are all cost, no benefit

A new systematic review has been published in Archives of Disease in Childhood, one the journals of the British Medical Journal, by Sandlund et al. titled “Child mask mandates for COVID-19: a systematic review”.

Since no randomised controlled trials have even been conducted on child mask-wearing or mask mandates, the authors systematically reviewed observational studies and included 22 in the final analysis: 6 found child mask mandates were associated with lower rates of infection; the other 16 didn’t.

But the studies with null results weren’t just greater in quantity; they were higher quality too.

Of the six studies reporting a significant negative correlation between masking and COVID-19 cases, five had critical and one had serious ROB [risk of bias]. Of the 16 studies failing to find a significant correlation, 1 (6.3%) had critical, 10 (62.5%) had serious, 5 (31.3%) had moderate and none had low ROB.

In short, almost all studies with critical ROB had pro-mask results, while all studies with moderate ROB did not. Table 2 below gives a breakdown of the various types of bias the reviewers found. The 6 studies with pro-mask results are listed first.

All six studies,20 ,21 ,22 ,23 ,24 ,25 reporting a negative association were potentially confounded by crucial differences between masked and unmasked groups, including the number of instructional school days, differences in school size, systematic baseline differences in case rates in all phases of the pandemic, testing policies, contact-tracing policy differences and teacher vaccination rates.

Almost all these confounds seem to apply to the worst of the bunch, Jehn et al., who found “the odds of a school-associated COVID-19 outbreak in schools without a mask requirement were 3.5 times higher than those in schools with an early mask requirement.” Unfortunately, this study was so bad even pro-maskers interviewed by The Atlantic said it was embarrassing. Among its many problems was that even though the study period was 15 July to 31 August 2021, "Some [schools] didn’t begin class until August 10; others were open from July 19 or July 21. That means students in the latter group of schools had twice as much time—six weeks instead of three weeks—in which to develop a COVID outbreak." No wonder the researchers didn’t want to share the raw data.

That study was published in the US CDC’s in-house propaganda rag Morbidity and Mortality Weekly Report, but even prestigious peer-review journals like the Journal of the American Medical Association (JAMA) have published similar rubbish by pro-mask scientists who gerrymandered results through a conveniently selected study design, as Sandlund et al. explain.

the Boston observational study [Cowger et al.23] stated they could infer causality between lifting school mask mandates and increases in student and staff cases by using a difference-in-differences technique. However, a subsequent reanalysis called the methodology and results of this study into question and failed to find the same association when expanding the population to include the entire state or using different statistical analysis and also found the initial study’s results were likely confounded by differences in prior infection rates.26

Interestingly, whereas as all pro-mask studies with critical ROB were done in North America (5 in the US; 1 in Canada), most of the studies with the lowest ROB were done in Europe.

In a Spanish study of almost 600 000 children, the researchers did not find a significant difference in cases between unmasked 5-year-olds and masked 6-year-olds; instead, case rates correlated closely with the age of children,27 which was also observed in another Spanish study.28…A lack of significant association between masking children and risk of COVID-19 was also reported by the UK Department of Education.30…A Finnish study compared case rates in children with and without mask mandates in 10–12 year-olds, and the authors found no reduction in COVID-19 case rates when mask recommendations were extended to include 10–12 year olds.39

All this means that Sandlund et al. come to the inevitable conclusion that “Real-world effectiveness of child mask mandates against SARS-CoV-2 transmission or infection has not been demonstrated with high-quality evidence.”

But the issue of child mask mandates isn’t just about mask effectiveness; it’s about potential harms too, such as negative effects on language learning and communication.

Mask wearing causes reduced word identification57–59 and impedes the ability to teach and evaluate speech.60 There is a link between observation of the mouth and language processing, and people of all ages continue to focus on the mouth when listening to non-native speech.61

Masks may also have negative psychological effects on children too.

There is also evidence that masks hinder social-emotional learning and language/literacy development in young children.67 Children with special-education needs and autism may be disproportionately impacted by mask requirements as they rely heavily on facial expressions to pick up social cues.68 Misinterpretation of facial expressions increases anxiety and depression in individuals.69 School environments with mask mandates were also found to have increased anxiety levels compared to those without mandates.70

Additionally, the physiological effects of masks may be worse for children than adults.

In addition, mask wearing has been associated with physiological harm2 13 13–17—many of which are more frequently reported in children than in adults2 17 71—which may have multiple negative downstream effects, including reduced time and intensity of exercise, additional sick days, reduced learning capacity, and increased anxiety. Masking has also been found to lead to rapid increase in CO₂ content in inhaled air—higher in children than in adults—and to levels above acceptable safety standards for healthy adult workers, which may rise further with physical exertion.72–74

This leads to a simple cost-benefit analysis of child mask mandates.

• Costs: potentially language learning and communication issues, worse psychological well-being, and negative physiological effects.

• Benefits: None

In conclusion, Sandlund et al. recommend that “Adults who work with children should be educated about the lack of clear benefits and the potential harms of masking children”.

Even though it would be too little too late, it’d be nice if some of the various governments around the world that forced kids to mask followed this recommendation. It’s a shame they won’t.