YOUNG: COVID-19 – Are masks really helpful?

Dr. Mandy Cohen, Secretary of the North Carolina Department of Health and Human Services, implores the use of face covering to stem the spread of the COVDI-19 virus during a press briefing at the Emergency Operations Center on Thursday, June 18, 2020 in Raleigh, N.C.

Dr. Mandy Cohen has told us we must wear masks in many kinds of settings. She told us that wearing the masks will help “fight” the COVID virus (named by WHO as SARS-CoV-2). Gov. Cooper has told us they are relying on “data and science.”

I am a scientist. I disagree.


Not long ago, I considered the COVID data our health experts were giving us. If masks were so effective, why were we not seeing improvement in the numbers? I decided to dive into the literature.

I should point out that this line of work uses a statistical technique used by epidemiologists called a meta-analysis. I am a statistician, but it’s really not as hard as it sounds.

A meta-analysis is a study of studies. A question is posed, and studies are gathered that address the question. Do masks work? A computer search of the research that has been reported is made based on key words. The papers that come back are filtered for relevance. The selected papers are then examined in detail in hopes of pooling the data from all of the papers. By pooling the data, conclusions are sometimes possible that would not have been seen in any one of the studies.

Statistics are used to determine if the summary result was simply due to randomness or whether a specific cause is indicated. A simple example can be helpful.

Imagine tossing a coin 30 times. A fair coin will result in heads about 50% of the time. But what if you suspect the coin you have is loaded — that is, it is not a fair coin? You suspect it because you toss the coin 30 times and you get heads only 40% of the time. Statistics can be used to answer your question — is your coin significantly different than the “fair” coin? Through meta-analysis, we can include multiple studies, so instead of 30 tosses, we can include the results for all the studies used in the meta-analysis studies.

The same analysis can be applied to the studies on wearing a mask. The question we are addressing is whether wearing a mask is any different than not wearing a mask? Instead of tossing a coin, of course, we examine results from randomized clinical trials (RCT). Using a meta-analysis allows us to use as much of the available RCT data as possible.

The evidence from RCTs suggested that the use of face masks either by infected persons or by uninfected persons does not have a substantial effect on influenza transmission.

I studied the studies and found one for influenza. The peer-reviewed meta-analysis study looked at flu viral transmission, using 10 randomized clinical trials. When you combine all 10, the study showed that the results are consistent with pure chance. Just how did the researcher characterize their results? “The evidence from RCTs suggested that the use of face masks either by infected persons or by uninfected persons does not have a substantial effect on influenza transmission… In pooled analysis, we found no significant reduction in influenza transmission with the use of face masks.” Adding up those infected while wearing a mask, 156/3495, 4.46%, and those infected while not wearing a mask, 161/3052, 5.23%, the results are consistent with chance.

I presented my opinion to Dr. Cohen and her staff. After some prodding, I heard from Mr. Fleischman, a senior official on Mandy’s staff. He provided me with another study that dealt specifically with the COVID-19 virus. Here is what I found.

The study he sent was a meta-analysis that looked at transmission of the virus. A total of 19 randomized studies were summarized. Here is what they had to say, “Medical masks were not effective, and cloth masks even less effective.” They also noted that “….respirators, if worn continually during a shift, were effective but not if worn intermittently.”

Mechanistically, masks have always only been thought to stop large droplets. Transmission through very fine droplets cannot be stopped by ordinary masks. Most recently, the CDC has confirmed that the virus can be transmitted through fine droplets. The meta-analysis that Mr. Fleischman had sent me supports this claim because, again, it showed no benefit to wearing masks. Incidentally, the Netherlands recently dropped the mask mandate saying the research did not support wearing them.

So why does Dr. Cohen insist that we wear masks?

There are risks for people over 65 with health problems, a fact known from the beginning of COVID-19. For those people, COVID can become a clinical treatment problem. Risks are dramatically lower for young, healthy people, a fact also known. Public health policy should reflect these realities. These two studies provide no scientific basis for one size fit all; if public health officials and politicians continue with mask mandates, then informed citizens might question if current policy is intended more to scare them than follow the science.

Dr. S. Stanley Young, Ph.D is an applied statistician, and a Fellow of the American Statistical Association and AAAS and Director of the Shifting Sands Project with the National Association of Scholars. He currently serves on the EPA’s Scientific Advisory Board.