Masks, effective transmission reduction strategy or performance theater?

One of the challenges of an environment in which there is a discrepancy between what government institutions want the evidence to be versus what independent researchers find the evidence to be is simply keeping track of the evidence over time as studies come out in dribs and drabs.

Inevitably, unless the issue is central to your existence or to your business, you end up with a running total in your mind, subject to faulty memory and confusion as the mainstream media often end up describing the results from the same study in dramatically different ways.

My impression of the effectiveness of mask wearing as prophylactic to disease spread was that it had low to negligible effect, much depending on the mask, the circumstances and the fashion of wear.  This impression was reflected in the standard protocols pre-Covid-19 which dismissed ordinary masks as ineffective.  The impression was further bolstered at the beginning of the pandemic when various health authorities sought actively to discourage people from mask wearing as an ineffective measure.

Then the mask bandwagon began to build and some, but not all, health authorities began encouraging mask wearing despite standard epidemic protocols, despite their own earlier recommendations against mask wearing and despite the absence of any rigorous studies supporting the effectiveness of mask wearing.

From the outside, it felt as if health authorities simply wanted to be seen to be doing something in the face of an unknown and frustratingly mysterious novel virus.  

As time went by, I began seeing more and more studies emerge from researchers around the world, some indicating support for the effectiveness of mask wearing and others indicating non-effectiveness.  I began keeping a running mental sum of the outcomes.

A further challenge was that the quality of the studies varied enormously, ranging from worthless to occasionally very rigorous.  Ideally what you are looking for are large population sample sizes adhering to randomly controlled trials, preferably with pre-registration of methodology and with open access to resulting data.  These were few and far between.  

My sense was that the stronger and more rigorous the study, the more likely it was to find that masks had little or no effect.

This is consistent with many of the case studies in Scientific Fictions: How Fraud, Bias, Negligence, and Hype Undermine the Search for Truth by Stuart Ritchie.  Some exciting finding is claimed (often in the field of sociology or psychology), there is tremendous media attention and pundit jabbering, essays are written, interviews given.  Over months and then years, efforts are made to replicate the exciting finding.  Eventually it is discovered that the findings fails to replicate and that the more rigorous the replication effort, the less likely it is to find the original results.  And despite all that, the original, un-replicated paper ends up keeping being cited in a positive fashion.  Think of the Implicit Attitude test, or claims about micro-aggressions or similar such nonsense.

The twitter account https://twitter.com/ianmSC, IM routinely posts charts showing the time of mask implementations and the case volumes over time.  Visually it is a striking argument against the effectiveness of masks even though RCTs are the better evidence.  See below:

Cases in Australia have reached a new high, another tremendous success story in Following The Science™

So sure, they’ve indefinitely destroyed the pretense of freedom in their country, but at least it’s also not working! pic.twitter.com/ydTcAxQoxl

— IM (@ianmSC) August 20, 2021

So masks, effective transmission reduction strategy or performance theater?

My conclusion for several months, on the balance of evidence, has been that it is performance theater.  It will still be some time before we really know, but Do Masks Work?  A review of the evidence by Jeffrey H. Anderson is a useful and reassuring confirmation that my running tally was broadly correct.  He discusses the issues around study design, RCTs as the gold standard for causal research, the cherry picking of weak studies which seems to have been a public health authority habit, and the results from the fourteen strongest designed studies conducted so far.

In sum, of the 14 RCTs that have tested the effectiveness of masks in preventing the transmission of respiratory viruses, three suggest, but do not provide any statistically significant evidence in intention-to-treat analysis, that masks might be useful. The other eleven suggest that masks are either useless—whether compared with no masks or because they appear not to add to good hand hygiene alone—or actually counterproductive. Of the three studies that provided statistically significant evidence in intention-to-treat analysis that was not contradicted within the same study, one found that the combination of surgical masks and hand hygiene was less effective than hand hygiene alone, one found that the combination of surgical masks and hand hygiene was less effective than nothing, and one found that cloth masks were less effective than surgical masks.

It is a  still hotly debated field, many further research efforts of increasing strength may overturn these findings, but I suspect we are getting onto firmer ground.  As a population strategy for reducing transmission, ordinary cloth masks (single or double masked) do not work.