Today, we are adding an important fifth metric to our COVID warning system: “daily new cases per 100K population” (also referred to by epidemiologists as “incidence”). The addition of this metric rounds out our warning system by incorporating a measure of how much COVID there is in each community today. Our previous metrics focused on direction of change and preparedness, but incidence corresponds to a person’s actual chances of being infected and suggests how many people will likely be infected in the near future. Learn more here.
Nine state risk scores have changed.
This is what the risk level map of the United States looked like on July 21 with the original four metrics:
This is what it looked like on July 22, with the case incidence metric added:
350 county risk scores have changed. 1800 new counties now have risk scores.
Adding the incidence metric has changed the scores of 350 counties. It has also allowed us to expand our coverage to more counties. Previously, many counties did not have enough data for us to calculate a risk score. CAN has always prioritized providing actionable data, and, since a lot of COVID decision-making by policy makers and residents will happen at the local—rather than state or federal—level, we believe it is critical to provide a county-level view of COVID.
We will now grade every county with a green case incidence score (less than one new case per day per 100K people) as green overall. If case incidence is not green, our normal grading system applies, whereby a state’s overall color reflects the highest risk color for any one of its metrics. Counties that have not reported how many cases they have will show up as grey.
Here is what the Covid Act Now map of counties looked like before:
Here is what it looks like now:
What does this change mean for my community?
We understand that taking into account Daily New Cases per 100K Population has increased the risk score for many states and counties. This change may be disheartening, but we believe it is important for our COVID risk score to reflect risk as accurately as possible and adding this metric improves our ability to do so.
In addition to helping our overall risk scoring be comprehensive, this new metric also has an important intuitive interpretation. As incidence increases, so does the risk that you’ll run into an infected individual on your trip to the grocery store or at a barbeque.
We also made a minor change to our contact tracing metric. Read more here.