Breaking down the numbers and understanding COVID-19 positivity rates

Medical Watch

CHICAGO — To determine the threat of COVID-19 in each community, we need to look to individual hospitals and the metrics they use to staff and prepare for an overwhelming number of COVID-19 patients. So while the city and state disagree over computing positivity rates, we’ll look at how those rates are determined and why one may be more telling.

“Today we are seeing overall this week increased numbers of patients,” Dr. Ernest Wang, NorthShore University HealthSystem, said.

“We’ve seen some increased emergency room visits we’ve seen increased hospitalizations,” Dr. Brian Stein, Rush pulmonary critical care physician, said.

“Our caseload has increased dramatically this month,” Dr. Jonathan Pinsky, Edward Hospital medical director of infection control, said.

From the city to the north and west suburbs, the story is the same, suggesting the next pandemic wave is upon us.

“Our positivity rate here is 16% this past week which is a jump too,” Wang said.

At NorthShore University HealthSystem, doctors calculate the positivity rate by dividing the number of patients with the disease compared to those symptomatic patients who were tested each day.

“Overrall I would say the person positivity when you’re looking at a population is the more accurate,” Dr. Karen Kaul said.

Kaul monitors testing at Evanston, Glenbrook, Highland Park, Skokie and Swedish Hospitals. She believes daily testing metrics are superior. Those are the numbers used by the City of Chicago. But the state calculates positivity rates rolling over at least a week. In that time, some patients may undergo several tests and each test is counted not just each patient.

“If you were looking at a single day the per person and Per test number should be very, very similar because we are not testing patients repeatedly in a single day, however if you were rolling those numbers over the course of a month for example you might have more patients who did get multiple tests,” Kaul said.

Rush University Medical Center pulmonary critical care physician Dr. Brian Stein says there are certain figures undeniably showing a surge right now.

“Most importantly is looking at the ER utilization, hospitalization and ICU utilization,” Stein said.

Patient loads are not at a panic level.

“We are certainly not feeling overwhelmed at this time,” Stein said.

But admittedly there is a lag from testing to hospitalization. More positive people today translates a week or so later to more hospital patients, then more in the intensive care unit.

“And just this week now we are getting 10 admissions a day and we are on pace to have a record number of admissions per week since we started getting COVID patients in March,” Pinsky said.

More older patients are presenting with severe disease at Naperville’s Edward Hospital. Pinsky is seeing a renewed shift in patient age.

“Over the summer we saw an increase in younger patients who were positive and now we are seeing a shift back to older patients. A lot of the older patients have been in contact with younger people infected,” Pinsky said.

“Several nursing homes in the area that are having outbreaks of COVID and that comprises about 40% of our admissions and that gets back to the importance of following precautions because what is happening is people in the community on the outside when they go home may be going to social gatherings and getting COVID and then bringing it back to the nursing home,” Pinsky said.

So now, it’s back to the crisis plan.

“We have a strategy but they are going to use, that we created during the summer months in our lessons learned from the first round and we are starting to mobilize those plans and see what we need to do because the numbers are growing,” Wang said.

Again, every medical expert has stressed, masks do help prevent the spread of disease. As does distance and frequent hand washing. In the frustration they urge: Don’t get complacent.

Listen to the Bair Facts on Health

Get the real facts on everything from diet trends to cutting-edge treatments, brought to you by Dina Bair and actual experts, so you can ignore the noise on social media and make informed decisions about your health.

Subscribe to the podcast

Apple Podcasts

Pocket Casts

Spotify

Stitcher

Popular

Latest News

More News