LETTER: In Defense of Science

Submitted by Jennifer Barro, MD, Retired physician and current GPS parent

Science took a beating in the lead up to the recent Greenwich Board of Education (BOE) mask policy vote. I am grateful that the majority of the board seemed to be weighing the question of whether, at this stage of the pandemic, with our local vaccination rates, declining test positivity, and decreasing hospitalization numbers, it would be time to lift the school mask mandate.

However, BOE member, Cody Kittle, chose to focus on the issue of whether masks decrease COVID-19 transmission. His op-ed declares that the mask mandate policy is a “failed and anti-scientific system.” His claim lacks merit.

Kittle’s assertion during the February 16th BOE meeting that there has “never been an established causal relationship between cloth masks and (COVID-19) transmission rates” is misleading on multiple counts.

First, epidemiological study designs are not generally structured to establish a causal relationship. In observational studies, demonstrating statistical significance means an association between two variables (i.e. mask use and decreased COVID-19 infection rates) is very unlikely to be a random occurrence, but causation is not tested or confirmed.

Second, he rebrands the mask policy as a “cloth mask” policy. The existing Greenwich Public School (GPS) mask policy, like most mask mandates, is not a “cloth mask” policy in language or in practice. The majority of students at Greenwich High School are wearing surgical masks with an occasional KN95 or cloth mask and the fraction wearing surgical masks at my daughter’s middle school is at least half. The rebranding may be a nod to the fact that mask efficacy evidence is strongest for surgical masks and N95/KN95s compared to cloth masks.

Most importantly, there is evidence that mask use is linked to decreased COVID-19 transmission. Each study may have its own set of limitations (as is generally true when studying humans and public health measures), but there is evidence ranging from laboratory analysis of particle filtration, to mask use being associated with better community COVID-19 transmission control and child (age 2 and up) masking being linked to less childcare program closure due to COVID-19 cases.

A study published last month reported that mask use is associated with decreased virus transmission risk when masks are worn by both an infected case and an exposed contact. More to the point, there are reports that K-12 school mask policies are associated with decreased COVID-19 case rates in Arizona, Massachusetts, Florida and 520 counties across the United States.

We are told that we need randomized controlled trials (RTC) as gold standard evidence, but in practice not every hypothesis is suited to a RTC design and public health decisions are made based on observational study evidence. It is unlikely that an institutional review board would approve a randomized school mask study, as it may not be ethical to assign children to a non-mask group with existing evidence that masks are linked to a decreased risk of COVID-19 transmission. I am sorry to break it to you, but a lot of medicine is practiced without that highest quality evidence.

Notably, Kittle misinterprets findings (in private correspondence) from a California study that reported surgical and N95/KN95 public indoor mask use was associated with decreased risk of COVID-19, but did not find a statistically significant difference for cloth masks. He points to this lack of statistical significance as “reaffirm(ing) that cloth masks are truly ineffective.” But, one cannot flip around a study conclusion of no statistical significance and use it as proof that cloth masks do not work. This is a subtle distinction, but a basic tenant of statistics that “the absence of evidence is not evidence of absence.”

Pushing his thesis to the extreme, Kittle proclaimed during the BOE meeting, that analyzing infection rates after removing the mask mandate would be a mistake because there will be natural oscillations in COVID spread (and he thinks masks don’t work). He is probably correct about future fluctuations, especially after school breaks or with new variants, but effective mitigation strategies could impact the magnitude of viral transmission and shrugging-off assessment of data seems particularly unscientific.

The GPS universal masking policy has been in line with the guidance from public health experts, the Connecticut Department of Public Health, the Center for Disease Control and the American Academy of Pediatrics. In his editorial, Kittle questions the motives of “authoritative scientists” and “experts” arguing they are incentivized to “conform to their peers, keep their job, and ascend the ladder of power and influence.” I embrace healthy, critical thinking, but we have witnessed public health officials suffer harassment and threats of violence during this pandemic because some presume that professionals are not acting in good faith and in the public interest. I believe it is reasonable to debate how to act on expert recommendation, based on local metrics and values, but dismissing the science and attacking the scientists is unfounded here.

It is possible to both acknowledge that masks are effective and decide that it may be time to remove mask mandates. I would like to echo BOE Chair, Kathleen Stowe’s recent statement of gratitude to bipartisan leaders in Hartford and in Greenwich who have helped our community navigate the COVID-19 pandemic, in part through mask mandates. I understand that many parents who have been asking to end the mask requirement hope that it will bring a sense of normalcy to our schools and students. We could all use some of that.

Jennifer Barro, MD
Retired physician and current GPS parent