- Public Health Madison and Dane County admitted Friday that it has been struggling to process a backlog of negative COVID-19 test results, skewing its reported infection rates.
In a massive update, the online data dashboard public health maintains added around 17,000 negative test results adjusting the positive rate from the past week down to 2.1 percent.
The percent positive rate measures how many COVID-19 tests have returned with positive results. Expressing the returns as a percentage helps account for if an increase in new cases is due to more testing or greater spread.
Public health uses the percent positive rate as one of its metrics in the Forward Dane reopening plan governing how and when certain social distancing measures, including many imposed on businesses, can be relaxed or eliminated.
Over the past couple of weeks, our data dashboard has appeared to have a high percent positivity rate," public health said in a Facebook post. "This is because each negative test has to be processed manually by a staff person. Our staff prioritize processing positive results, and as the amount of testing has increased, we have had a backlog of negative tests to process."
In the past several weeks, it had not been uncommon for Dane County's percent positive rate for the most recent day to begin in the double digits and then slowly adjust lower as time passed and the county processed more negative tests.
The numbers on the data dashboard gave the impression that the county was continuously seeing greater spread of COVID-19.
Dane County, according to the now up-to-date dashboard, did see a sharp increase in COVID-19 cases beginning in late June. However, that rate began to subside as the weeks progressed.
To read more go to WKOW: https://wkow.com/2020/07/24/dane-county-catches-up-on-covid-19-testing-backlog-counts-17000-more-negative-results/
Photo: WKOW