Some readers of the Kansas City Region COVID-19 Data Hub have submitted questions regarding recent trends in the positivity rate, which is displayed in the school gating criteria section of the hub. First, we would like to thank all these readers for reaching out and sharing great questions. We hope the explanation below helps clarify how the positivity rate is calculated and how changes in tests and reporting can impact positivity rates.
How is positivity rate calculated on the Kansas City Region COVID-19 Data Hub?
The positivity rate may be calculated differently by other organizations or on other websites. On the data hub, we calculate the positivity rate based on the data we receive from our partner jurisdictions. The positivity rate for a jurisdiction can fluctuate based on changes in either of the two inputs used for the calculation: total reported cases over a 7-day period and/or total reported tests over a 7-day period.
What trends are impacting positivity rate?
At a regional level, we have seen a dramatic decline in reported tests, which is likely playing a significant role in positivity rates. We are seeing two concurrent trends:
- PCR testing in the region is genuinely declining, as shown on the testing page of the data hub.
- Some local jurisdictions are updating testing data less frequently while they continue to prioritize publishing frequent updates to cases and deaths to keep the public informed of risk in the region.
Both of these trends suggest we may see rising positivity rates and/or positivity rates that rise and fall dramatically depending on when jurisdictions update their testing counts.
What is the bottom line?
Our partner jurisdictions are working hard to collect and report data as regularly as possible, and we continue to strive to quickly apply new tests, cases and deaths to the appropriate date of occurrence. Changes in reporting patterns can affect what’s presented on the data hub. We recommend viewing the positivity rate with this context in mind and reference the additional testing and case data on the data hub.