Analysis of BYU Report: Efficacy of Masks for COVID-19

Analysis of BYU Report: Efficacy of Masks for COVID-19

July 19, 2020 BYU report: 

I am a resident of Salt Lake County and have been directly impacted by the BYU report released on July 19, 2020.  Governor Herbert used this report to inform his decision to mandate masks for K-12 schools throughout the State of Utah for the Fall semester.  This impacted approximately 666,858 K-12 students, two of which are my own.  Naturally, I was disturbed by this sweeping mandate that not only impacted the students, but also the parents, staff, and faculty of every school in Utah.  I could not let this happen without examining the contents of the BYU report.

In June, Salt Lake County Mayor Jenny Wilson wrote a letter to Governor Herbert requesting a mask mandate for Salt Lake County.  In her letter, she cited two studies, but misinterpreted the findings.  In fact, the studies do not support a county-wide mask mandate, even though she used them as if they did  (see SL County Mayor Misinterprets Scientific Data on COVID-19).  My attempts to bring awareness of these misinterpretations to Governor Herbert, Lieutenant Governor Cox, and Mayor Wilson, fell on deaf ears.  Regardless, it is imperative to continue to hold our public officials accountable for the mandates they enforce upon the citizens of Utah.

In light of my discovery of the misinterpretations of the scientific studies, I decided to take a close look at the BYU report.  I will acknowledge up front, that I am against mask mandates for all citizens and therefore, I examined the BYU report with this bias, although my approach was to keep an open mind.  If the BYU report presented compelling evidence that public masking is effective in reducing the transmission of COVID-19, I wanted to be persuaded, mostly because it would be much easier for me to go along with the majority of the populace than to swim upstream by vocalizing a different perspective.  On the surface, the BYU report is very compelling in support of public masking.  However, not until you dig below the surface will you find that the compelling arguments begin to unravel.

As I began reviewing the BYU report and the Ben Abbott Lab website, I was greatly encouraged by the refreshing approach the BYU team took in tackling this project.  The team consisted of four researchers who reviewed 115 articles/studies on the efficacy of masks.  Here is an excerpt from their opening remarks in the report:

“Scientific evidence can be difficult to interpret under the best of circumstances.  During a global pandemic (and election year), it is no surprise that there is public confusion about what measures can effectively protect families and communities from COVID-19.  Because the scientific and medical understanding of this disease is advancing so rapidly, we decided to put together a plain-language summary of the science on face coverings – a.k.a. masks.  As lifelong residents of Utah County and scientists, we felt a responsibility to respond to the technical questions asked by friends and family.”

These remarks communicate their intentions, which I take at face value.  As a fellow Utahn of 24 years, I can hear their concern and care for their friends, neighbors, and community members.  I appreciate their intentions.  Professor Abbott provided an FAQ section to answer questions that his team was receiving following the release of their report.  The initial FAQ section answered some of my immediate questions, such as, how the articles were selected, and whether he has a bias toward face masks.  The team selected the articles by searching Google Scholar and Web of Science for scientific studies specifically dealing with COVID-19 and masks.  They favored reviews and summaries because of the strength of multiple studies over a single study.  But perhaps they were not aware of the censorship Google has engaged in regarding COVID-19, masks, and treatments, so unknowingly, they built in a pro-mask bias into the selection of their studies.  Regardless, I found it remarkable that they were open to receive feedback regarding any errors they made and any studies they overlooked that are critical to the discussion.  Their openness to critical feedback increased my confidence in the integrity of their team.  But what about the question of their own personal bias?  Below is an excerpt from the FAQ section:

“To the question of bias, yes, like all humans, we are. Our beliefs and values influence how we see the world around us. We discussed this as a group of authors and worked hard to provide a fair summary of the literature. Staying neutral was helped by the variety of political views and backgrounds among the co-authors. We take scientific integrity extremely seriously, plus I believe that we have a God-given responsibility to be honest. We recognize there are inevitable gaps and room for improvement, but we have done my best to accurately represent the scientific literature.” 

It was beyond my capability to review all the articles referenced in their report, but I reviewed 16 of the studies they used, and an additional 6 studies referenced within the original 16 studies.  In total, I reviewed 22 articles.  My goal was to examine a sampling of articles to assess whether the BYU team accurately represented the findings from the scientific studies or if they fell into the same trap as Mayor Wilson.

The BYU report made 34 statements based on the 15 articles I reviewed (the 16th article I reviewed, the team did not reference in their July 19th report).  Of those 34 statements, 15 of them were consistent with the findings of the studies they referenced, 14 of their statements were not supported by the studies they referenced, and even more disturbing, 5 of their statements were contrary to the findings.  (For a more detailed look at the studies and statements the BYU report made regarding the findings from these studies, see Appendix 1: Scientific Evidence for Efficacy of Masks and Appendix 2: Scientific Evidence for Asymptomatic Transmission).

One of the primary arguments in support of community wide mask mandates is that masks provide ‘source control’ (“my mask protects you, your mask protects me”).  MacIntyre et al. (2016, Study #33) defines ‘source control’ as masks used by sick individuals to prevent transmission to others.  In other words, masks control the spread by controlling it at the source, i.e. the sick person.  Given the belief that asymptomatic people can spread the virus as much as symptomatic people, ‘source control’ has been expanded to include healthy people.  If healthy people wear a mask, it can control the potential for an asymptomatic carrier of the virus (a healthy person) to transmit it to others.  Therefore, two crucial questions need to be answered:  

1) Is there scientific evidence that masks worn by healthy people prevent the spreading of the virus within the community? 

2) Is there scientific evidence that asymptomatic people transmit the virus like symptomatic people? 

The BYU report attempted to address both these questions, however, the studies they selected to answer them had substantial limitations.  I will provide a few examples here, but I encourage you to read Appendix 1 and Appendix 2 which details the limitations.  In one example, Kenyon (2020, Study #11) provided an ecological study addressing the efficacy of public masking to slow the spread of COVID-19.  While Kenyon (2020) found that face mask use was negatively associated with the number of COVID-19 cases, they acknowledge a serious limitation, that is, “the association may be entirely explained by unmeasured confounders.”  In other words, their findings are not conclusive, but merely suggestive.

In a second example, a Lancet article written by Cheng et al. (2020, Study #6) was not a scientific study, but rather a paper written by public health officials on the importance of community masking.  Cheng et al. (2020) used the argument that masking works as ‘source control’ because of the possible asymptomatic transmissions of COVID-19.  Unfortunately, their “scientific evidence” for asymptomatic transmission was drawn from the findings of Zou et al. (2020, Study #73) in which they found the viral load from nasal and throat swabs of an asymptomatic patient like that of symptomatic patients.  It’s important to note that as of 9/2/2020, Zou et al. (2020) has been cited 974 times by other scientific articles/studies.  This is extremely unusual for an article published in March to be cited this often, especially when other COVID-19 related articles are cited less than 100 times. The fundamental problem with the findings from Zou et al. (2020) is that they are based on only one asymptomatic patient.  It is irresponsible for researchers/experts/public health officials to cite this article as evidence that asymptomatic people transmit the virus.  A fundamental principle of scientific research is that the strength of your findings largely depends on the size of your sample.  Yet somehow the scientific community has no qualms in using the results from one asymptomatic person as the primary resource to support the notion that asymptomatic carriers spread the virus like symptomatic carriers.  

An egregious act on the part of the BYU team is that not only did they use the Zou et al. (2020) study along with other studies that relied on the Zou et al. (2020) study, but they embellished the study’s findings.  

Zou et al. (2020) draw the following conclusion:

“The viral load that was detected soon after symptom onset and similar viral loads were detected in the asymptomatic patient was similar to that in the symptomatic patients, which suggests the transmission potential of asymptomatic or minimally symptomatic patients.” (emphasis mine)

The BYU report draws the following conclusion from Zou et al. (2020):

“This means that there is a high risk of transmission from asymptomatic carriers.” (emphasis mine) 

There is a clear discrepancy between “potential risk” and “high risk” which points to the bias among the BYU team in support of community masking.  To their credit, they removed this section entirely from their most recently updated report, which leads me to believe that this error was pointed out to them.  Unfortunately, the damage was already done; Governor Herbert relied on this report to guide his decision to mandate masks for K-12 students.

It’s unfortunate that the BYU report did not include a more conclusive study regarding asymptomatic transmission of COVID-19.  Gao et al. (2020) found no transmission of an asymptomatic carrier of COVID-19.  In this study, a 22-year-old woman presented to the hospital for congenital heart disease and was tested for COVID-19.  She tested positive but was asymptomatic.  Researchers traced her contacts for 5 days prior to her testing.  They identified 455 people she came in contact with.  COVID-19 tests were given to all 455 people and ZERO came back positive.  This study, among others, led Dr. Maria Van Kerkhove, the WHO’s Head of Emerging Diseases, to report that the spread of COVID-19 by patients who are asymptomatic is “very rare”.  She stated on June 9, 2020,

“from the data we have, it still seems to be rare that an asymptomatic person actually transmits onward to a secondary individual.  We have a number of reports from countries who are doing very detailed contact tracing.  They’re following asymptomatic cases.  They’re following contacts.  And they’re not finding secondary transmission onward.  It’s very rare.”  

It seems like an oversight from the BYU team to not include this study in their report.  Perhaps it’s a result of using Google Scholar.  The study did not come up in their search results because Google censored it given it does not support the narrative that asymptomatic carriers transmit the virus like symptomatic carriers.  It’s also possible the BYU team excluded it because the findings do not support the overall tone of the BYU report.  Or maybe it just simply was missed somehow.  It’s hard to know for sure, but it causes one to wonder.

In summary, the intentions of the BYU team were admirable, but their execution demonstrated clear biases that unfortunately led Governor Herbert to mandate masks for approximately 666,858 students.  Unfortunately, the BYU team, to some degree, fell into the same trap as Mayor Wilson.  This emphasizes the importance of recognizing the politicization of the virus and the necessity to exercise prudence by digging deeper for the truth.  We are living in times when we can no longer take at face value conclusions researchers make, instead, we need to read the studies, digest the findings, and investigate whether the conclusions drawn are consistent with the findings.  But who has time for this?  Not many people do.  I hope that this analysis and summary of the BYU report helps to inform you in a way that leads to a greater awareness, so that you can make educated decisions for yourself and your family.  Please help spread the word.

Back to blog