It’s the Narrative not Science That Drives Misinformation
Two weeks ago, a headline crossed my screen, “Still using cloth masks? It’s time to switch to surgical – here’s why.” This is a hot topic for me. As a school board member, I follow mask effectiveness quite closely. I clicked. The CNBC article (via Apple News) referenced a rigorous academic study demonstrating how limited masks are at stopping COVID-19, only to leave the reader with the opposite impression. This provides a lesson in how inconvenient scientific facts can be coopted to promote an opposite but convenient narrative. Here is how it happens.
The narrative: Do your part in stopping the spread of COVID-19 by wearing a mask.
For 18 months, the CDC has promoted this narrative without any rigorous scientific studies to back it up. As a society we are owed confirmation this is true.
Good science is out there but don’t trust the media to tell you about it
The best scientific studies are called Randomized Controlled Trials (RCT). In these RCTs, researchers design a study involving two or more groups. The scientists assign the groups randomly and introduce a change. They keep the rest unchanged as a control. If the change shows a statistically significant effect on the one group without change to the other, you have learned something significant. The larger the groups, the more meaningful the results.
Most prior academic studies of masks were not RCTs because often everyone wore masks. The studies lacked randomization and control. In August 2021, Yale researchers released the results of an honest-to-goodness RCT on masks. Researchers tracked 342,126 adults in 600 villages in Bangladesh. They segmented the villages into three categories: asking one group of villages to wear surgical masks, asking another group to utilize cloth masks, and a third group to wear no masks. Then they tracked COVID infection rates (with blood tests) and confirmed compliance in using the masks.
As we should expect from rigorous scientific efforts, the researchers also documented the particulars of the materials used. Masks were hooked up to instrumentation to confirm how much each of the two mask types trapped or passed through small particles. In the lab, cloth masks filtered 37% of particles while surgical masks filtered 95% of the same particles. This measurement wasn’t the point of the study. It was simply a baseline so other researchers could repeat their efforts, a hallmark of scientific efforts. Then they went out into the field to study how these masks held up against a virus in everyday use.
The facts are not the problem
What did they find? This landmark study revealed two key outcomes: 1) cloth masks failed to show any statistically significant reduction in spread of the virus, and 2) surgical masks show some benefit (a 10% reduction in spread). A deeper look into the 10% improvement reveals that the improvement differed by age. Participants over 50 years old (who are presumably more conscientious) that saw anywhere from a 23% to 35% reduction in infection and no significant benefit in the rest of the population (<50 years). When you include all adults, surgical mask effectiveness, in real-world usage, drops to 10%.
From the scientific work we can conclude: if you are in the roughly 1/3 of adults who conscientious in wearing surgical masks, you might be able to expect a 30% reduction in risk of spreading COVID-19. For everyone else, masks, particularly cloth ones, provide no benefit.
Prior to seeing the CNBC article, I had read the study (yes, I read academic studies in my spare time) and was intrigued to see how this was characterized.
Inconvenient facts can be spun to salvage a convenient narrative
The article’s author, Cory Stieg, is a blogger on personal health. Had Stieg referenced the study’s actual results, I am certain this article would have not gotten broad traction. Stieg made no mention of the study results and referenced only the baseline statistic that “surgical masks are 95% effective at filtering out virus particles — compared to just 37% for cloth masks.” This left the reader with the impression that while cloth masks work well, surgical masks work much better. The blog went on to extol the benefit of switching from a cloth mask to a surgical mask or a KN-95 type, conveniently leaving out how the masks that most people use (cloth ones or poorly fit surgical types) don’t provide any protection.
To further align with the narrative, Stieg references governmental authorities, “Today, the CDC maintains that well-fitting cloth masks can still effectively prevent the spread of Covid.” The incontinent truth is that this Yale/Bangladesh mask study exactly proves that the CDC is wrong. Cloth masks don’t work at all. Surgical masks are only effective when worn by the most conscientious folks.
Stieg’s take isn’t technically inaccurate (surgical masks are better than cloth) but it is dramatically shading the truth. As a blogger, that is entirely fair. But when CNBC picks up the blog and publishes it on the CNBC website, they have crossed over into misleading, if not outright misinformation. Apple News then promotes this to a billion or so people that use iPhones or iPads and you have misinformation that has the most convoluted link to scientific facts.
In Conclusion
Through much of 2020, we had a poor understanding of COVID-19. The facts were few and far between. In 2021, that is changing. There is good science being practiced out there and even a few countries (the UK and Israel for example) are publishing the facts. Unfortunately, traditional media and many US government institutions have adopted a convenient narrative. No inconvenient facts will sway them. We are on our own to choose trusted sources of critical information.
[Note: This post represents my return to writing weekly. I have switched to Substack as it is less likely than any other outlet to censor the writings of its contributors. If you do not want to receive these messages weekly, just let me know.]