Milwaukee’s Extended Indoor Dining Closure Reduced COVID-19 Spread

The decision by Milwaukee Mayor Tom Barrett and then-Health Commissioner Jeanette Kowalik to maintain a prohibition on indoor dining, even after a state restriction was removed, significantly reduced the spread of COVID-19, according to a new study.

Milwaukee was one of four cities studied that chose to maintain its indoor dining restrictions even when wider state restrictions were lifted. Compared to seven big-city peers with indoor dining, the study found that new COVID-19 cases were reduced by 61%.

The study, conducted by researchers from Drexel University, examined the period from March to October 2020. Milwaukee could have allowed indoor dining again starting in mid-May, but maintained a blanket restriction until June 5th when it started a process to steadily expand indoor capacity.

“Keeping indoor dining closed may be directly or indirectly associated with reductions in COVID-19 spread,” concludes the study. “Evidence of the relationship between indoor dining and COVID-19 case rates can inform policies to restrict indoor dining as a tailored strategy to reduce COVID-19 incidence.”

The authors of the study note that they deliberately sought to examine indoor dining, and not dining as a whole, because key sources of transmission are indoor, poorly-ventilated spaces. Other studies they reviewed did not examine the split between indoor and outdoor dining.

For each of the four studied cities that maintained dining closures, Milwaukee, Indianapolis, Philadelphia and San Francisco, a “time zero” was established when the city could have reopened. For each city, the study looked at the two weeks before time zero and the six weeks after.

The study found that keeping indoor dining closed averted 142 cases per day in the average studied city. Including the seven control cities that reopened indoor dining, the authors estimate that 44,521 cases could have been averted across four weeks. Starting five weeks after reopening, the study found that case rates in cities that reopened were 3.52 times higher compared to the week before reopening.

“We estimate that, after adjusting for other non-pharmaceutical interventions, COVID-19 rates decreased by 61% over six weeks in cities that kept indoor dining closed compared to cities that reopened,” wrote the authors.

“Indoor dining has not only been associated with increased COVID-19 incidence, but also has been shown to potentially be responsible for some of the stark racial-ethnic COVID-19 disparities. Higher death rates in Black and Hispanic populations are driven by higher rates of infection and exposure, in large part thought to be due to higher rates of occupational exposure,” says the study. The authors suggest future studies of this with more detailed datasets.

The study was published in the journal of the International Society for Environmental Epidemiology​.

The study authors acknowledge limitations with the available data. Some cities reopened indoor dining while maintaining restrictions on other activities, while others like Milwaukee maintained a prohibition on virtually all indoor activities.

The authors also noted that the treatment cities were smaller, have higher transit ridership and larger minority populations than the control cities. The seven control cities were Atlanta, Austin, Charleston, Dallas, Houston, Phoenix and San Antonio.

The study, as well as the underlying data sets and code to analyze it, is freely available online.

And while Milwaukee’s decision to allow bars and restaurants to reopen in June 2020 was a lifeline to a struggling industry, it wasn’t met with universal admiration by the businesses themselves. Many stayed closed, for various reasons, for weeks, if not months longer.