Data differences, delays from private labs behind discrepancies in COVID-19 rates Iowa says
CEDAR RAPIDS, Iowa (KCRG) - Iowa’s Governor’s Office pointed to differences in data reporting and delays from private labs in explaining discrepancies KCRG-TV9 found in the positivity rate of COVID-19 tests in Iowa.
The positivity rate measures the percentage of COVID-19 tests performed that come back positive for the virus. Health experts point to it as a key measure of both the state of the pandemic and the effectiveness of measures to control the spread. The CDC recommends keeping a daily positivity rate below 5% to reopen in-person schools and businesses. Iowa Governor Kim Reynolds is using a 15% positivity threshold for school districts to get an exemption to move all classes online.
KCRG-TV9 tracking of state data, however, found the state’s coronavirus website has consistently published a lower positivity rate. For the 14-day rate as of Friday, the state’s website reported a positivity rate of 10.2% while KCRG-TV9 tracking of state-reported data found a positivity rate of 11.8%. Broken down by individual days, the state’s published positivity rate was consistently lower than the rate KCRG-TV9 found.
Pat Garrett, the spokesperson for the Governor’s Office, pointed to two primary reasons for this. First, he noted the state’s website publishes tests and cases based on the date the test was performed. KCRG-TV9 and other media outlets report and track cases by when the state reports them. That means a case reported today may show up on the state’s website days or even weeks in the past. That will consistently cause the state website to display fewer tests and cases for the most recent days, which will then be updated as test results get reported.
Garrett emphasized no one is trying to hide anything but argued the state’s method is the most accurate historically to track the virus and is the one state epidemiologists are focused on.
Garrett said that delay is exacerbated by reporting delays from private labs in reporting cases. In some cases, private labs are taking 8-12 days after a test to get the result to Iowa officials. Garrett says tests done by the state at the State Hygienic Lab at the University of Iowa are very quickly uploaded into the state’s reporting system, often within 24 hours of the test. Private labs, however, some of which are out of state, take longer to report cases to the Iowa Department of Public Health.
That is one reason Garrett said the state is pushing to expand testing capacity in the state. State-managed tests are much quicker to get into the state’s reporting system, giving doctors and the public a more accurate view of the virus in their area. He says expanding state testing will also make it much easier for Iowans to get a COVID-19 test, which experts point to as essential in resuming “normal” life during the pandemic.
The state’s cases and positivity rate jumped Friday more than normal, in part due to the addition of positive Antigen tests. The state had already reported the tests in its data but labelled positive results as inconclusive as it awaited verification on the reliability of the tests. That added about 1,300 new cases to the state’s website spread out over several weeks.
Even removing the Antigen testing, the state reported a record-high number of new cases for a second straight day on Friday of more than 1300 new cases and a positivity rate of about 40%.
In response to surging cases, Governor Kim Reynolds shut down bars and taverns in 6 counties Thursday - Linn, Johnson, Black Hawk, Polk, Dallas and Story. She said younger age groups, particularly 18-24, are behind the surge and suggested the return of college students gathering at bars and parties were a significant factor.
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