Missouri Department of Health explains why numbers on daily COVID-19 graph changes regularly

Published: Jul. 6, 2020 at 6:24 PM CDT
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Paul Petruska started tracking confirmed cases to try and guess when the state might start to reopen a few months ago.

Recently, the Department of Health and Senior Services started only giving the total for the whole pandemic. You'd have to do your own math to figure out how many new cases appeared.

"You couldn't go back and check the day before," Petruska noted. "So if you get a total, cumulative new case, you don't know what that means. It means nothing."

His frustration goes deeper. A bar graph tracks the data better, but Petruska noticed results changing constantly.

"On June 23rd, Missouri announced 434 new cases in their cryptic way of not giving you a number, but me doing math."

Three days later, the graph showed June 23rd's total was 296.

"Two days later [June 28], it's up to 317. One day later [June 29] it's up to 352. That's not helpful to anybody," Petruska said.

An editorial in the St. Louis Post-Dispatch called the adjusting of numbers political.

"The data that we present each day, and multiple times per day is not something that's affected by anything with politics," said Lisa Cox, Communications Director for the DHSS.

The DHSS says the graph changes day-to-day because it first reports cases as the day the test was taken. It uses that date as a place holder.

Once the local county health department talks with that case to see when they first felt sick, the state moves it to that day.

"With epidemiology, what we're really interested in is when the person got sick, and how long they've been ill for, because that's really what guides all of our public health interventions," said Dr. Nathan Koffarnus, an Epidemiologist with the DHSS.

Petruska says amending numbers in that way isn't helpful. He hopes for a better system before more people get frustrated like him.

"People that are out there that want to know what the risk is, it's great to have objective numbers that you can rely on and not something that's been adjusted based on memory," Petruska said.

The state is now separating the swab test results from the antibody test results. You can view the state's website