COVID-19 is bigger than ever in Ohio, with the number of new daily cases reaching its highest points of the pandemic in July. As the disease continues to spread throughout the state, Gov. Mike DeWine has struggled to balance public health needs with a growing sentiment against public health measures.
Before last week’s statewide mask mandate, the main strategy from the administration has leaned on a county-by-county approach that mandates masks in high-spread counties with less resistance to such measures and preserves local authority in areas of lower spread and more antipathy to mandates. This strategy led to a mask mandate for 60% of Ohioans and lighter regulation in places with less spread and less taste for mandates.
Whatever your personal view is on masks mandates, however, available evidence on their use during the COVID-19 pandemic seems to show they slow the spread of disease. Much of the news coverage of the use of masks has focused on very technical questions: What kind of mask needs to be worn to spread disease? How should a mask be worn? Are masks more protective for people wearing them or people around those who wear them?
Whatever the answers are to these questions, the available evidence seems to show us one thing: that mask mandates do slow the spread of disease. A study published in Health Affairs last month by two University of Iowa public health researchers is possibly the most rigorous and applicable study on COVID-19 mask mandates to date. The researchers compared the infection trajectory of 15 states that implemented mask mandates in April and May to the other 35 without mandates to see if mandates showed any measurable impact on infection rates.
The “natural experiment” of variable mask mandates suggests that mask mandates reduced infection rates. The researchers found that growth rates in COVID-19 cases declined by one percentage point in the first couple of weeks after a mandate compared to states without mandates and that case decline rose to two percentage points in the weeks after.
One or two percentage points of growth rate decline might not seem like a lot, but the researchers estimate that the mask mandates prevented at least 230,000-450,000 new infections through the end of May, implying they saved a combined 9,000-17,000 lives over that time period assuming the current 3.7% national COVID fatality rate.
While this study seems to suggest mask mandates can save lives, reduced growth rates might be the effect of other factors. For instance, states that have a larger cultural commitment to reducing the spread might be likely to both adhere to social distancing guidelines and pass mask mandates as well. While the study tries to control for these factors, only so much control can be made in a natural experiment such as this.
These problems present a sticky challenge for DeWine. On the one hand, the evidence available suggests that mask mandates slow spread of disease and save lives. On the other hand, Ohio is a hotbed for anti-mask sentiment and communities need to be on board with masks for mandates to work. DeWine has a difficult path to tread as he tries to convince people to take steps that will slow the spread of COVID-19 and save lives in the process.