How to Make Sense of COVID-19 Statistics

Jul 1, 2020

An infectious disease specialist at the University of Iowa Hospitals and Clinics says coronavirus case numbers are meaningless unless they're put into context.

Michelle O'Neill reports. 


Dr. Jorge Salinas, Hospital Epidemiologist, University of Iowa Health Care
Credit submitted / University of Iowa Health Care

Dr. Jorge Salinas is Hospital Epidemiologist for University of Iowa Health Care in Iowa City and an Assistant Professor of Internal Medicine at UI's Carver College of Medicine.

He says to understand COVID-19, look at more than one statistic.

"It's always also good to look at more than one data source. Even though the numbers are the same, they may be displayed differently and may convey a different message. So it's better to look at things from different angles. So yes, I agree that case counts, especially cumulative case counts, will only go up. And the best that can happen to cumulative case counts is that they can remain flat or the same number." 

The data he tracks include daily reports of new, positive tests. "So the increases that we're seeing in eastern Iowa are calculated using incidence, so the new cases per population. The rate of accumulation of new cases is going up. So there is no doubt that there is more transmission occurring in eastern Iowa." 

The epidemiologist also says it may be confusing when case numbers rise while COVID hospitalizations and deaths are going down. Dr. Salinas says that's because of the delay between the onset of infection and when symptoms show up and then get worse.