Rhode Island’s coronavirus cases have been on the rise for several weeks, but an inconsistency in the way testing data is being interpreted has made monitoring the situation murky.
While the state’s three-day average of new cases hit triple digits on July 24 for the first time since early June, the state’s percentage of positive tests has varied widely, depending on who is tracking the data and how it is calculated.
Rhode Island officials and their counterparts in other states have been monitoring positive testing rates in each state to help determine whether visitors need to quarantine when crossing state borders.
When the R.I. Department of Health released COVID-19 data on Aug. 5, the agency reported a positive testing rate of 2.7%. That same day, the U.S. Centers for Disease Control and Prevention and other tracking websites said Rhode Island had a positive rate of 6%.
Why the difference? There is no “standard definition of calculating percent positivity,” said Dr. Jennifer Nuzzo, an epidemiologist at Johns Hopkins University’s COVID-19 Testing Insights Initiative.
Rhode Island has been including test results from people who have been tested repeatedly, such as staff members and residents at nursing homes. Meanwhile, Johns Hopkins calculates a positive rate by excluding repeat negative and positive results.
“[Rhode Island’s] approach could potentially dilute their positive percentage,” Nuzzo said, adding that the method of counting multiple tests for the same person in a state’s overall positivity percentage is “less epidemiologically relevant.”
It’s not that Rhode Island health officials are ignoring this type of calculation. RIDOH uses Johns Hopkins’ tracker to implement 14-day quarantining restrictions on visitors from those states with positivity of 5% or more, as recommended by the World Health Organization.
Rhode Island exceeded that limit by hitting 5.3% on July 31 and then again on Aug. 4. That same day, Connecticut, New York, New Jersey and Massachusetts started requiring Rhode Islanders to quarantine when visiting those states.
Much of New England is reporting positivity percentages below 3%, according to Johns Hopkins’ tracker. But it is not clear which states are reporting which calculation.
RIDOH spokesman Joseph Wendelken said the numbers on Johns Hopkins’ COVID-19 tracker are incorrect and inconsistent.
“They have an issue with how they are mapping our COVID stats,” said Wendelken. “The way that they’re counting percent positive is off because they’re just not using correct numbers.”
Wendelken said that Rhode Island is one of few states reporting both statistics – number of tests and number of people tested.
In a letter obtained by Providence Business News, RIDOH Director Dr. Nicole Alexander-Scott wrote to another website, the COVID-19 Tracking Project by The Atlantic, which is reporting the same numbers as Johns Hopkins University. Alexander-Scott asked the site to report uniform data for each state.
“We strongly support reporting with uniform measures across states, and support that the measure be number of tests rather than people,” she wrote.
Nuzzo said if the percent positivity is increasing, a state should be concerned well before it hits the 5% rate.
“It’s an early warning that means that something could require serious additional attention,” said Nuzzo.
Alexa Gagosz is a PBN staff writer. Contact her at Gagosz@PBN.com.
On a note related to COVID testing, friends of mine who were going to the Cape signed up for rapid COVID testing through portal.RI.gov at the R.I. Convention Center. At last Wednesday’s update, the Governor, in response to travel advisories imposed on RI travelers by NY, NJ, CT and MA, established the rapid testing center at the Convention Center for Rhode Islanders traveling to those states and guaranteed results in 24-48 hours. It has been 5 days now since the test and neither of my friends has not yet to receive their test results.
What gives Gov?