The Governor’s office has combined multiple testing data points to give the appearance of a downward trend of coronavirus cases across the state.
An analysis of how different state leaders have tackled reopening the economy found Arizona among a handful of states where an incorrect use of coronavirus testing data has led to businesses potentially opening before it is safe to do so.
During a May 4 COVID-19 news conference briefing, Gov. Doug Ducey used a graph showing a declining rate of positive tests, citing the downward trend as justification to allow barbers, salons and restaurants to reopen.
What Ducey did not disclose during the televised news conference was that the figures combined diagnostic and antibody tests. Positive results from diagnostic tests were declining, according to published state data, but adding the antibody tests made the decline look steeper.
Jennifer Nuzzo, at the Johns Hopkins Center for Health Security, said many of the problems at the state level could be due to the challenges of deploying a disease surveillance system amid the chaos of a pandemic. Health departments often lack current technology and rely on paper forms and other outdated systems.
Nuzzo said COVID-19 has become politicized, creating pressure for officials to make their states’ data look good.
“It may feel tempting to want to manipulate the numbers to look rosier than the situation really is,” she said. “But that’s a short-lived strategy. You can’t hide dead bodies.”
Elected officials across the state depend on coronavirus testing and infection-rate data so they can anticipate whether a second wave of contagion is coming — and whether additional restrictions such as closing parks, or prohibiting certain businesses from reopening, are necessary.
In a continuing theme for the outbreak in the United States, a lack of federal leadership persists. Even the U.S. Centers for Disease Control and Prevention has been lumping together tests that measure different data points. The absence of federal guidance has left states to report testing figures in different ways, and that can lead to frustration and confusion about what the numbers mean.
In some places, there have been data gaps that leave local leaders wondering whether they should loosen or tighten restrictions. In others, officials are accused of spinning the numbers to make their states look better and justify reopening.
Such errors render the CDC numbers about how many Americans are infected “uninterpretable,” creating a misleading picture for people trying to make decisions based on the data, said Ashish Jha, director of Harvard’s Global Health Institute.
“It is incumbent on health departments and the CDC to make sure they’re presenting information that’s accurate. And if they can’t get it, then don’t show the data at all,” Jha said. “Faulty data is much, much worse than no data.”
Officials at the CDC and in multiple states have acknowledged that they combined the results of viral tests, which detect active cases of the virus essentially from the onset of infection, with antibody tests, which check for proteins that develop a week or more after infection and show whether a person has been exposed at some point in the past.
Viral test results should be reported separately, public health experts say. That allows for tracking of how many people have confirmed active infections, the percentage of people testing positive and how those numbers change over time — all crucial for guiding public policy.
Mixing the results makes it difficult to understand how the virus is spreading. It can give the false impression that the rate of positive test results is declining.
According to the CDC, the problem started several weeks ago when the agency began collecting data from states using an electronic reporting system that had been developed for other diseases. At the time, nearly all lab results being reported were from live viral testing. But in the ensuing weeks, antibody tests expanded and CDC officials realized they had a growing number of those mixing in with the viral results, the CDC’s Dr. Daniel Pollock said.
Pollock said officials are working to separate the data, but it is a labor-intensive process that could take another week or two. He acknowledged the agency could have moved to fix the problem sooner.
“Hindsight is 20/20,” he said.
But while officials at the CDC work on separating viral and antibody tests, Gov. Ducey’s office shows no signs of following suit. During the governor’s most recent press conference on May 20, data presented to the public still displayed viral testing with antibody testing.
The Arizona Department of Health Services already separates the data on the state website, allowing Ducey to divide the data without delay. When asked if there were plans to divide the data to be more in-line with the CDC’s plans to display testing results, the Governor’s office declined to comment.
The Associated Press contributed to this report.