Georgia Health News: State’s ‘map’ of coronavirus cases — not the actual numbers — now under fire as ‘criteria’ keeps shifting.

Georgia Health News: State’s ‘map’ of coronavirus cases — not the actual numbers — now under fire as ‘criteria’ keeps shifting.

 

 

By Andy Miller
Georgia Health News

How the state illustrates its pandemic statistics continues to draw criticism from health and data experts. The benchmarks for a state map on cases per 100,000 population keep changing as COVID-19 cases surge, leading to concerns that this may confuse the public.

The color-coded thresholds for Georgia coronavirus cases per 100,000 have risen at least three times since mid-April. The criteria for the most severely hit counties, depicted in red, increased from at least 200 cases per 100,000 to at least 2,224 per 100,000, critics say. This month, it’s risen from 2,961 to 3,302.

And on Wednesday, the threshold went even higher, to 3,391.

Currently, the number of “red’’ counties remains low, at four out of 159, on the Department of Public Health’s website, as well as a map from the Georgia Emergency Management and Homeland Security Agency.

The four are thinly populated Chattahoochee, Stewart, Randolph and Echols counties. The state’s website adds, “This chart is meant to aid understanding whether the outbreak is growing, leveling off, or declining and can help to guide the COVID-19 response.”

Matt Hayat, a biostatistics expert at Georgia State University’s School of Public Health, said the American Statistical Association’s ethical guidelines state that publications and reports should convey findings in ways “that are both honest and meaningful to the reader.’’

“The lack of transparency with assumptions about the data and analysis are very concerning and likely misleading for the public,’’ Hayat said. “The use in the daily situation report of altering groupings and thresholds over time obscures understanding of how the outbreak is changing.’’

Increasing the threshold of maximum severity does not reflect the accelerating spread of the disease recently, Hayat said.

A spokeswoman for Public Health, Nancy Nydam, said that the maps “are not designed to show increases over time but rather to show density by location and differences between counties.’’

They should not be compared to each other, she said. “If the ranges are not periodically reset, the entire map would end up one color and viewers wouldn’t be able to make distinctions between locations.’’

Trends over time are presented in the epi curve in the plots to the right of the map, Nydam added.

Hayat, however, said that curve is also misleading. At the far right, the curve “gives an impression of cases dropping. They aren’t.’’

Dr. Melanie Thompson, an Atlanta physician who has been a critic of the state’s handling of COVID-19, also said the map doesn’t reflect the current status of the pandemic.

“One reason is that they continue changing the scale, and the number of cases included in each band of color,’’ Thompson said. “I have seen counties increase their cases or case rates substantially, only to maintain the same color on the map because the scale changes. The map links to the epidemic graph, which is helpful, but of course the epidemic graph is backdated so it always looks like the most recent two weeks are getting better. None of the maps reflect the recent status of the counties.’’

She pointed to maps used by the White House Coronavirus Task Force as better in tracking what is happening in recent weeks.

The state data presentation has taken flak previously. Here’s an AJC article that pointed to some of those issues.

 

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