The Iowa Department of Public Health is changing the way it calculates and reports the state’s coronavirus positivity rate.
The net effect of that change will be a lower positivity rate as the state factors in a greater number of negative tests tied to individuals who, because of their jobs or other factors, take the test repeatedly. In recent weeks, Iowa’s positivity rate has hovered around 26%, meaning more than one of every four tests that is counted by the state results in a “positive” finding.
Beginning this week, IDPH officials will calculate the state’s positivity rate by dividing the number of positive tests over a two-week period with the total number of tests, both negative and positive, administered during that same time period. That is the same method used by the U.S. Centers for Disease Control and Prevention to calculate positivity rates, according to IDPH, and should result in more accurate state-to-state comparisons.
As things stand now, the 14-day positivity rate in Iowa is computed using the number of individuals who tested for the virus rather than the larger, total number of tests given.
IDPH Interim Director Kelly Garcia said that at one time, during the pandemic, approximately 125,000 Iowans had been tested, but 1.3 million total tests had been conducted. “And now, just four months later,” she said, “we’ve nearly doubled the number of individuals tested and tripled our total tests.”