Where do people at the most risk from COVID-19 live in Wisconsin?
Analysis can help areas strategize for response
What ZIP codes throughout Wisconsin have the highest proportion of adults at high risk of severe complications from COVID-19? Where should public health departments allocate the most resources? What areas should be monitored the most closely?
Researchers at the University of Wisconsin-Madison have pulled together information to help answer those questions.
The researchers drew from electronic health records to identify ZIP codes throughout the state that have higher percentages of adults who are older or who have medical conditions, such as obesity and diabetes, that put them at greater risk if infected by the coronavirus.
“We found substantial variation across communities in the proportion of people who had these risk factors for severe complications,” said Maureen Smith, a physician and professor at the University of Wisconsin-Madison School of Medicine and Public Health. “That finding suggests that matching community with the right resources needs to take into account that communities are different.”
The information — pulled together when the crisis first hit the state — could be even more important in the coming months as businesses reopen and more people venture from their homes.
That could increase the risk of the virus spreading not only in urban areas but also in rural parts of the state that have not seen a large number of confirmed cases.
“There are rural ZIP codes with a substantial portion of people who are at risk of severe complications,” said Smith, a professor of population health sciences and family medicine.
For example, in Oconto County, 46% of the adults in the 54138 ZIP code and 47% in 54175 ZIP code have two or more risk factors. In Chippewa County, 36% to 40% of the adults in three ZIP codes are at the same risk. In Forest County, 44% of the adults in the 54566 ZIP code have two or more risk factors.
Risk factors include age, severe obesity, diabetes, compromised immune systems from medical conditions such as lupus, rheumatoid arthritis, HIV/ AIDS or multiple sclerosis, serious heart conditions, kidney failure, liver disease and chronic obstructive pulmonary disease, or COPD.
“It is important when we think about all of these communities,” Smith said. “We really need to recognize that we are only as safe as every community is safe.”
Some experts see the pandemic evolving into patchwork of small epidemics. And for many small communities, the first wave has yet to hit.
“It’s not one big epidemic,” Caroline Buckee, associate professor of epidemiology at Harvard University T. H. Chan School of Public Health, said in a podcast from the Brookings Institution. “It’s multiple small epidemics.”
That increases the importance of understanding the potential risk to different communities.
Rural areas, for instance, have a larger percentage of people who are older. They also have fewer physicians and hospital beds.
The information compiled by UW researchers can help identify potential hot spots, said Jessica Bonham-Werling, director of the Neighborhood Health Partnership Program, which prepared the reports, at the UW School of Medicine and Public Health. That in turn can help public health and other officials make decisions on where to allocate resources, from testing and contact tracing to community services, such as delivering groceries.
In all, at least 35% of adults in about 15% of the ZIP codes in the state have two or more risk factors for severe complications from COVID-19.
The information — which can be seen on an interactive map — also shows the wide variation within counties.
That variation has been seen in Milwaukee County, where the pandemic has disproportionately affected first African American communities and now Latino communities.
Milwaukee County has seven ZIP codes where 35% or more of the adults are at severe risk of complications.
The pandemic also has disproportionately affected people who work in low-wage jobs and who are more likely to live in intergenerational households.
“COVID-19 really has shown where the tears are in our society,” said Mary Kay Fahey, a spokeswoman and director of membership and business development for the Wisconsin Collaborative for Healthcare Quality.
The percent of people at risk of severe complications was drawn from electronic health records provided by more than 20 health systems to the the Wisconsin Collaborative for Healthcare Quality, known as WCHQ.
Information that can identify individual patients is not included in the data.
The organization, founded in 2003 by health systems, had been working with the Neighborhood Health Partnership Program to look at quality measures by ZIP code.
WCHQ and the UW researchers realized the information for that project would be used to estimate the percentage of adults at risk of developing severe complications from COVID-19, said Matt Gigot, director of performance measurement and analysis at the organization.
The variation within the counties, Gigot said, shows the importance of having detailed information.
Information from electronic health records was used to release detailed reports last year on the differences in health and health care experienced by people in Wisconsin depending on their race, income, health coverage and geography.
The Wisconsin Public Health Research Network has helped get the information on which ZIP codes have large percentages of people at risk to public health officials throughout the state. Reports also were prepared for specific health systems.
“Reliable and accurate data is absolutely essential in preparing for, responding to and recovering from COVID-19,” said Smith, who is director of the Health Innovation Program at the UW School of Medicine and Public Health. “And that’s why this WHCQ data is so important.”
“Reliable and accurate data is absolutely essential in preparing for, responding to and recovering from COVID-19.”
Maureen Smith
physician and professor, University of Wisconsin-Madison School of Medicine and Public Health
The Health Innovation Program is a campus-wide program that works with health systems and community organizations to improve health and health equity in the state.
The Neighborhood Health Partnership Program, an affiliate, was established partly to help that effort by providing information on health outcomes and care at the neighborhood level.
The maps produced for the pandemic are an example of what the program hopes to do — and Smith said they will be important in matching the right resources with the communities that need them in the coming months.
“It is critical to understand that we are all only as safe as the members of our community who are most at risk,” she said.