By Jeremy Olson
Minneapolis Star Tribune
New modeling by Minnesota researchers of the COVID-19 pandemic showed that social distancing isn’t as effective as initially expected in reducing deaths and infections, but will still help protect the state from a novel and highly infectious coronavirus.
Initial models were based on estimates that Minnesota’s statewide stay-at-home order would reduce face-to-face contact and disease transmission by 80%, but the new model released Wednesday showed it only reduced that by 59.5%.
COVID-19 remains a new disease globally, and new understanding is helping to create a more precise model, said Stefan Gildemeister, state health economist, as he unveiled the new modeling results on Wednesday morning. Initial estimates of the impact of social distancing were based on experiences in China, where the coronavirus first emerged.
“Mitigation (in China) was very different from what we were experiencing here,” Gildemeister said.
The modeling predicted roughly 1,700 deaths in Minnesota by the end of May, but a range of 16,000 to 44,000 deaths over 12 months of the pandemic. That is higher than prior state modeling estimates, Gildemeister said, based on updated understanding of an earlier peak of the pandemic and broader spread of the virus in the state.
“We hope these are pessimistic estimates, but it is certainly a plausible outcome,” he said.
The latest model also was based on feedback from doctors that 100% of people would die from COVID-19 if they needed ventilator care in hospitals to breathe and didn’t receive it.
Minnesota hospitals have worked to increase ventilatory capacity in the past two months, and now have 3,702 available —though 858 remain on back order. As of Wednesday, only 562 ventilators were in use statewide by patients with COVID-19 and other patients with medical problems unrelated to the pandemic.
Modeling of different scenarios showed that stay-at-home orders would reduce ventilator demand and deaths. A stay-at-home order through the end of May would cut in half the forecasted number of deaths compared to the state doing nothing at all from the start.
Gildemeister said modeling will continue to be updated as new information comes in about the virus and people’s compliance to social distancing.
“It possible for these mitigation effects to change further depending on how the population interacts in response to good weather or sort of how compliance varies over time,” he said.
Modeling was instrumental early on in the pandemic for Gov. Tim Walz, who issued school closures and statewide stay-at-home orders based in part on state-specific forecasts showing that COVID-19 cases would far outstrip the available supply of critical care beds and ventilators in hospitals.
The last model update was publicly unveiled on April 9. Walz has made key policy decisions in the absence of new forecasts —including another two-week extension of the stay-at-home order that is scheduled to end May 18.
Walz is expected to extend the order again Wednesday night, though he could make exemptions for additional classes of businesses. In recent weeks, the governor has permitted nonessential manufacturing and warehousing sites to reopen if they have social distancing plans in place, and retailers to reopen for curbside pickup or delivery services.
The latest modeling prediction of deaths in Minnesota remains substantially higher than predictions in other models around the U.S. State researchers have stressed that the goal of the modeling is not to predict precise death estimates, but rather to show how changes in social conditions could reduce cases and deaths.
