The most uncontroversial article about toddler masking in the world

Some things we can hopefully all agree on, on a topic where there is trouble agreeing

The use of facemasks has been one of the most controversial elements of the Covid-19 pandemic. Recently discussions have become particularly agitated over masking pre-school aged children (aged 2 to 5 years) in particular. Given this polarisation, I thought it was high time for a completely uncontroversial article on the topic which no one should be able to find anything to disagree with.

I will set the scene with some uncontroversial facts:

The use of facemasks is recommended for pre-school aged children (aged 2 and older) in the USA by both the Centre for Disease Control and the American Academy of Paediatrics.

The routine use of facemasks is not recommended for children under the age of 5 by the World Health Organisation and UNICEF.

There are no countries in Europe which recommend masking pre-school children.

Effectiveness

The evidence over the effectiveness of facemasks for preventing transmission of SARS-CoV-2 is considered controversial by many. Some people think that the existing mechanical and observational evidence is overwhelmingly in favour of them being an effective intervention, some others think this evidence is either biased or not applicable to real world settings, and some think the evidence is suggestive of a small or negligible benefit.

I will not put my hand into this wasps nest now (this article is supposed to be uncontroversial), but I will say something which should be totally uncontroversial.

Whatever your thoughts about the existing evidence base, studies which are conducted on adults or school aged children are not generalisable to pre-school aged children.

Many medical interventions have to be adapted to the youngest children because they are developmentally very different to their older counterparts. These include medicines given as liquids rather than tablets, and even administration devices such as the use of spacers for asthma inhalers. Young children cannot reliably learn to use certain types of devices or medicines appropriately.

The effectiveness of facemasks is almost entirely dependant on the fit of the mask to the face, and the compliance of the wearer. It is reasonable to suggest that pre-school aged children cannot comply to the behaviours necessary to make facemasks effective to the same extent as adults or older children. Children aged 2 - 5 years are a special case, and we cannot extrapolate from other age groups. Anecdotes about how compliant individual families children may be with wearing masks are not evidence of compliance at a population level.

Given the above, it is therefore reasonable to suggest that effectiveness of facemasks in pre-school aged children may be lower than in other age groups, which would reduce their benefit.

Harms

It is true that there are no proven harms from mask wearing in pre-school children. However, this cannot tell us that there are no harms, as the research has simply not been done. That means that if there were harms, we would not know about them - despite it being true to say that no harms have been proven.

Given the lack of evidence, what is important is to ask whether there are plausible mechanisms by which harms could occur.

We know that children’s speech, language and social development are undergoing key processes during the pre-school years. We know that observing faces is an important part of developing these skills. We know that wearing masks obscures important parts of children and caregivers faces.

These harms could potentially be small at an individual level, but be important at a population level. Therefore, individual health providers claiming that they have not seen evidence of this in their practice is not evidence that the harms do not exist. Equally, it is worth noting that a many speech and language services are indeed finding themselves more busy than usual following the pandemic, but we cannot be sure whether this is specifically due to mask wearing or other factors such as reduced socialisation, family stress, backlog from difficulty accessing services etc.

Given the above, it is therefore reasonable to suggest there is a plausible mechanism by which harms could occur from requiring pre-school aged children to wear face masks.

It must therefore, also be unreasonable to claim definitively that there are no harms from requiring pre-school aged children to wear face masks, as this is not known, and could plausibly be false.

Regional differences

The fact that different countries do, or do not require pre-school aged children to wear face masks is not evidence in itself that this practice is, or is not a good idea. Similarly, just because some specific institutions do, or do not recommend it is also not evidence in itself that this practice is, or it not a good idea.

What these differences should be considered evidence of is that there is no consensus or definitive evidence on either the effectiveness or harms of their use in this population. Making definitive claims is therefore misleading.

Trust

Public health institutions have lost a lot of trust during the pandemic, often due to oversimplified messaging which does not accept uncertainty. This is a valuable lesson which we must learn from moving forward.

A statement such as,

“There are concerns regarding how facemasks might impact the speech and language development of young children, however any impacts are likely to be small and outweighed by potential benefits of reducing transmission.”

is reasonable, even if people may disagree on the direction of the weight of evidence.

Statements such as,

“If caregivers are wearing masks, does that harm kids language development? No. There is no evidence of this.”

are unequivocal and misleading. This kind of messaging can seriously undermine trust in health institutions and should be avoided.

Summary

Requiring pre-school aged children to wear face masks is controversial. We cannot extrapolate evidence of their effectiveness in adults or older children to pre-school children, as their ability to comply and the fit of masks can reasonably considered different enough to make this non-generalisable.

It is incorrect and misleading to claim definitively that there are no harms from their use, because in the absence of evidence this cannot be known, and there are plausible reasons to believe that harms could occur to speech, language and social development. This is why many countries, and organisations such as WHO and UNICEF do not recommend the use of facemasks in this age group.

Anecdotes of where harms may have, or have not occurred due to facemasks in individual children are not evidence of the presence or absence of systemic harms.

Health organisations should not make unequivocal claims about the effectiveness or harms of an intervention where these are not known and where reasonable debate exists, such as that demonstrated by the large regional variation in the use of facemasks for pre-school aged children and their carers.

Regardless of whether we believe an intervention to be good or bad, it is vital that health professionals and organisations are accurate in their messaging and do not claim certainty where reasonable disagreement exists.

Otherwise we risk further harming our ever-more fragile relationship with the public.