Statewide mask mandate’s effects prove challenging to measure
When the pandemic first broke out, the owners of Guadalajara Restaurant on Milwaukee's south side decided to do carryout only.
It wasn't until recently that the family-run Mexican restaurant resumed operations on reduced hours.
Still, manager Fabiola Estrada said, she often has to remind customers to wear face masks — a task made easier now that the entire state is under a mask order.
“Having it be a mandate takes some of the pressure off,” Estrada said. “It's a requirement, and it's not up to me. It has made it easier to enforce.”
Since Gov. Tony Evers issued the statewide mandate a month ago, many businesses say they are fighting fewer battles against customers who are resistant or unused to wearing them.
But whether the mandate has anything to do with the decline in new cases in Wisconsin over the last month is a much tougher question to answer, according to public health experts.
Between mid-June and late July, the number of new daily cases was rising
dramatically, with the state going from an average of about 300 new cases per day to 900.
After Evers issued his statewide mask mandate on July 30, the number of new cases per day began falling. Wisconsin now sees between 700 to 800 new cases per day on average.
But public health experts warn that there are no simple explanations.
While the decline in new cases could be due to the mask mandate, it could also be due to people changing their behavior in other ways, such as staying at home more, experts said.
“It is hard to find these causal relationships,” said Nasia Safdar, a professor of infectious diseases at the University of Wisconsin School of Medicine and Public Health.
Safdar said wearing masks needs to be considered along with other measures such as whether people are physically distancing, how much mask use differs from county to county and whether people are wearing their masks properly.
Anecdotally, there does seem to be more mask use around Madison, Safdar said. But masks won’t work if people are wearing them around their chin or under their nose or if they take them off to talk.
“If you ask them if they wear masks they all say ‘yes,’ but it has to be worn the right way,” she said.
In addition, the percentage of tests coming back positive — a metric that many public health experts watch even more closely than the number of new cases — has ticked upward in recent weeks, from around 7% when the mask mandate went into effect to 8% as of Friday. An increased test positivity rate is an indicator of more virus circulating in the community.
Public health experts said people should bear in mind it is difficult to definitively link any event — whether it’s a mask mandate, election or protest — to a subsequent rise or fall in cases.
That’s because these events take place in real life, not in controlled experiments.
“It becomes very hard to tease things apart when you’re looking at human behavior,” Dr. Amesh Adalja, an infectious disease expert with the Johns Hopkins University Center for Health Security, told the Milwaukee Journal Sentinel recently. “It takes really sophisticated studies to control for those variables.”
A few researchers have attempted such studies. In June, University of Iowa researchers published a study in the scientific journal Health Affairs comparing states that passed mask mandates to those that did not. The researchers attempted to control for differences between states such as their population density, social distancing policies and their case growth trends.
Their study found that states with mask mandates saw their case growth rate fall in the weeks afterward. The researchers’ model suggested that the mandates helped prevent more than 200,000 cases by late May.
In July, researchers who conducted a similar study in Germany found that regions of the country that mandated face masks saw a 15% to 75% reduction in the number of new infections in the 20 days after their mandatory introduction.
Skepticism from some
Although public health experts are in agreement that masks are a low-cost and effective way to prevent the spread of COVID-19, not all members of the public are convinced.
In an informal Journal Sentinel reader survey in July, just before Evers’ mandate, 46% of respondents said they would not comply with a statewide mask mandate, citing concerns such as government overreach and distrust of scientific experts.
Nelson Lang, a general manager at El Rey Supermarket in Milwaukee, said the statewide mask mandate has been helpful for talking to customers, but some remain defiant.
“It’s been difficult before and after, to be honest, because people are very opinionated about that topic, and they believe one thing or another,” Lang said.
In an essay published in the Washington Post on Thursday, Tom Frieden, the former director of the Centers for Disease Control and Prevention, said the politicization of mask-wearing and the federal government’s poor communication had made health experts’ job harder.
Frieden said a review of the latest scientific research shows that surgical and N95 masks are the most effective but in low supply. If unavailable, people should use a tight-fitting mask with three layers of cotton or cotton-synthetic material.
Masks should be used in any public indoor area where others are present and there is community spread of COVID-19, Frieden said, but they are probably not necessary outdoors except when people are packed close together.
At an Aug. 13 news conference, Evers said the mask mandate anecdotally appeared to be helping business owners and school officials encourage people to wear face masks.
And he said public health officials would continue to promote mask-wearing even if case numbers did not fall significantly.
“We believe in masking,” Evers said.
Jessica Rodriguez is a Report for America corps reporter for the Milwaukee Journal Sentinel. Please consider supporting journalism that informs our democracy with a tax-deductible gift to this reporting effort at JSOnline.com/RFA.