COVID-19 Event Risk Assessment Planning Tool

Although Thanksgiving is behind us, we are still in the midst of the holiday season. It is a festive time of year that is normally accompanied by personal and work-related social gatherings. Many people are cutting down on social events either voluntarily or due to city-wide stay at home orders like the one that was issued in Los Angeles on November 27.

However, gatherings of individuals from different households are still being organized and attended across the country. If you are thinking about organizing an event or considering attendance at an event where there will be 10 or more participants, did you know that you can estimate the chance that at least 1 COVID-19 positive individual will be present? The COVID-19 Event Risk Assessment Planning Tool uses county-level COVID-19 data, in combination with the number of attendees. To get your estimate, simply move the “Event Size” slider to approximate the number of attendees and navigate on the map to the county where the event is to take place.

While the tool is intended to be simple to use, it has limitations like any other predictive model. Since we don’t test every American on a regular basis, the actual number of COVID-19 cases is greater than the number of documented cases. It has been estimated that for each confirmed case of COVID-19, there are 10 times as many unreported cases. Another study estimates that there are anywhere from 6 to 24 times the number of unreported cases for each reported case. Hence, the COVID-19 Event Risk Assessment Planning Tool includes a variable called “Ascertainment Bias” which denotes the number of actual cases for each documented case. The tool defaults to an ascertainment bias of 5 (i.e., for each documented case, there are 5 times as many actual cases) but allows you to change it to 10.

The tool has many other features including global risk estimates, real-time US and state-level estimates, and others. Read more about the risk assessment tool in this article, or click on the “About” tab in the tool to see data sources and links to articles about the tool. Stay safe everyone!