A new mask randomized trial shows that masks work?

Not so fast. There are at least four limitations worth knowing about. This is how to read trials.

Atle Freithem and colleagues report in the British Medical journal the results of a pragmatic randomized control trial. The take-home message is that wearing a surgical mask for 2 weeks during the winter season of 2023 reduced the spread of self-reported viral illness. According to some, the study proves masks work.

First, I commend the authors for running a randomized control trial. Many will know that I interviewed Atle during the covid-19 pandemic and he proposed randomized control trials of school closure. Any randomization adds to the knowledge base here. I supported all of those randomized studies.

Second, having said that, this study does not prove masks work. The primary endpoint of the study is self-reported illness. Over the last 4 years, globally, we have witnessed one of the greatest propaganda campaigns to convince the public that mask work. They have been the topic millions of news hours of coverage. And the constant trumpeting by proponents online.

Given, that many people believe masks work, and given that there is no placebo control or sham control in this study, it is entirely possible the result is driven by the placebo effect alone. If you wear a mask, you feel like you do better. A better endpoint for future mask studies would be some objective measure of viral spread, like serial swabbing, or sero prevalence. This study just tells me that people who wear masks report fewer viral illnesses, not that they actually were infected less or felt better overall. The study does not find a benefit on documented covid-19 infections, though it lacked power for this.

Third, if there's a new virus out there, and it's very deadly, and a vaccine is coming just a few months away, it makes total sense to try to delay getting the virus. But if you're going to be living in a world of these viruses, and they aren't that deadly, like covid is not currently that deadly, you might not get it this year, but you might get it next year. The question isn't, can you avoid getting a virus for a few weeks or a few months? The question is: are you better off wearing a mask year after year? For every winter, and at the end of 5 years or 10 years or 15 years, are you better off? This study's follow-up is just too short.

The analogy I like to use is say you're about to run a marathon. And somebody wants you to take a special energy drink. That energy drink means you run the first mile faster. And that's where the study ends. But obviously you don't care about the first mile, you care about the whole race.

Fourth, if we really did devise away for people to have fewer respiratory viruses each winter season will they really be better off? It's taken for granted that people don't like colds, and I don't like them either. But our knowledge of the immune system is so primitive we have no idea what the impact of annual respiratory illness is. It is entirely possible that there are other domains of health that will be impacted by having fewer respiratory viruses. When I was growing up, parents routinely were happy that their kid got sick, realizing that the sooner they got it over with the better the rest of childhood would go. That wisdom no longer persists today in a world of safetyism, but there is little empirical data on how many infections someone should get and when. Maybe it's not good for a 50-year-old to avoid cold, setting them up for a devastating cold when they're 80.

Fifth, the biggest take-home message of this study is that randomized control trials are possible. Probably of every single academic in the United States, I am the person who has said that most often and most repeatedly. If you cannot run randomized controlled trials of non-pharmacologic interventions, then you should not be mandating them. Anthony Fauci, famously failed America because even though he controlled the research budget, he ran precisely zero studies. His legacy is not one of heroism, but one of scientific failure. I've written about that before for sensible medicine.

In conclusion, if someone tells you this randomized control trial proves that wearing surgical masks work, the only thing they've successfully proven is that their brain doesn't work. Knowing how to read articles should be the fundamental education of medical school, instead it is memorizing trivialities. We need more randomized control trials of masking so we can decide whether or not the few zealots who continue to mask today are doing something sensible, or crazy. Until we get those studies we don't know for sure, though some of us have a guess.