How to use regional COVID-19 data to make decisions about day-to-day life

(This story was updated at 9:09 p.m. on May 5, 2022, to include an accurate hyperlink to “vaccination and booster rates” on OHA’s website.)

map of Oregon showing different color-coded regions

Now that Oregon’s mask mandate has ended for most indoor public spaces, people may feel uncertain or uneasy about venturing out without masks. How do we decide to go to the movies or a friend’s party? What factors should we use to make a decision?

To help answer these types of questions we recently published a self-assessment guide. Another source for decision-making is scientific and statistical data. The Centers for Disease Control and Prevention (CDC) and Oregon Health Authority (OHA) offer multiple data resources that can help you make choices about day-to-day activities.

But first, know there’s a lot of data. And you might wonder, “Where do I even start?”

For guidance, we spoke with Betsy Ladyzhets, a science, health and data journalist who has been covering COVID-19 since the beginning of the pandemic. She is a journalism fellow at the Brown Institute for Media Innovation working on publishing and analyzing reports on COVID-19 data.

Ladyzhets offered a few tips, starting with the CDC.

CDC’s community-level data

In earlier days of the pandemic, looking at the number of COVID-19 cases in your region and whether it was rising or falling was a reliable indicator of risk. But that’s changed.

“Case numbers are not as reliable now because a lot of people are testing positive at home and those tests are typically not reported to public health agencies,” Ladyzhets said.

That’s why the CDC started adding another factor into the mix: hospital data. By measuring COVID-19-related hospitalizations with newly reported case numbers, the CDC rates individual counties with low (green), medium (yellow) or high (orange) levels of COVID-19 spread.

To learn the risk level of your community, go to the CDC’s community-level webpage and enter your state and county. Here, the example is Multnomah County, Oregon, where the risk level is currently “medium.”

screen shot of CDC's community level spread for Multnomah County

The site also offers guidance for each risk level. If your community level is high, for example, wear a well-fitting mask indoors in public, regardless of vaccination status (including in K-12 schools and other indoor community settings). If your community level is medium, and if you are immunocompromised or at high risk for severe disease, consider masking and taking additional precautions.

To dig deeper into your county’s COVID-19 situation, use the CDC’s Integrated County View and again enter your state and county. The results on this page also include a variety of interactive tools and data for vaccination and booster rates, testing, hospitalizations and deaths in your county.

screen shot of CDC's community level spread for Multnomah County, going into more detail

“If you’re in a green (low) community level, that doesn’t mean COVID-19 is not circulating in your area, but it means if you do get COVID-19 and you get sick, there is likely a hospital bed available for you,” Ladyzhets said. Medium or high community levels mean hospital capacity is stretched thin, and you should consider wearing a mask in public or limiting social gatherings.

OHA’s website offers additional data to help measure personal risk

  • HospitalsOHA’s hospital capacity dashboard shows rates of COVID-19-related hospitalization by region, as well as bed capacity, illness severity and COVID-19 patients by hospital.
  • County data – OHA also offers a regularly updated snapshot of county-level case, death and test positivity data.
  • WastewaterWastewater analysis is a good indicator of community spread because it doesn’t rely on COVID-19 test results or hospital data. Carriers of the COVID-19 virus shed virus particles in their urine and feces, so even if people don’t have symptoms or access to testing, OHA’s wastewater data will still show whether the virus is present in a community – and if it’s spreading. And because people are often infected with COVID-19 a few days before they feel symptomatic, new case numbers tend to lag behind wastewater data by three to five days. So if virus levels are increasing in the wastewater, that could mean more people will soon test positive. Oregon has one of the most robust wastewater monitoring programs in the country, with approximately 40 communities participating around the state.
  • Vaccination rates – Higher vaccination rates in your community offer another layer of protection. If you are up to date on your vaccinations (initial series plus booster), and you know that most of the people around you are as well, you might feel safer in indoor public spaces. OHA’s website shows vaccination and booster rates by state, county and ZIP code.

How to use all this data

To determine personal COVID-19 risk, you could start with CDC’s community-level tool to determine whether your county poses low, medium or high risk. Then maybe you look at the wastewater data on OHA’s website.

If, for example, the CDC shows your county at “low” community spread, but wastewater data show virus levels rising in your area, you may still feel comfortable going to a movie but you may want to consider wearing a mask.

How to absorb available data from multiple sources and use it to make safety decisions for yourself and your community is not an exact science.

Ladyzhets follows the “Swiss cheese model” of personal decision-making. No one layer of protection – masks, social distancing, vaccines, etc. – is perfect. Like Swiss cheese, each layer has holes. But if you layer those slices of Swiss cheese on top of each other, some holes get covered. If you layer COVID-19 protections, such as getting all your recommended vaccine doses and wearing a mask indoors, for instance – your protection level rises. If you’re vaccinated but don’t wear a mask indoors, your protection level is lower.

“In any given situation, I want to make sure that I have three or four layers of [protection],” Ladyzhets said. That could include wearing a mask indoors around other people, making sure a space is well-ventilated, rapid testing right before an event, or not attending social events if cases are rising.