The US Food and Drug Administration misstated how many coronavirus patients a study showed would be helped by treatment with convalescent plasma, the New York Times reports.
The agency issued an Emergency Use Authorization for the treatment on Sunday, a decision President Donald Trump hailed as "truly historic," according to CNN. It adds that during the briefing, US Health and Human Services Secretary Alex Azar said study data from 70,000 volunteers indicated treatment with convalescent plasma led to a 35 percent increase in survival.
But that number — which the Washington Post notes was repeated by FDA Commissioner Stephen Hahn — has been called into question, it adds. The number, it says, appears to come from a confusion of absolute versus relative risk, and only refers to a subset of patients in the Mayo Clinic study.
Hahn acknowledged the error in a tweet, the Post adds."I have been criticized for remarks I made Sunday night about the benefits of convalescent plasma. The criticism is entirely justified," Hahn writes on Twitter. "What I should have said better is that the data show a relative risk reduction not an absolute risk reduction.
CNN adds that the study instead found 8.7 percent of patients who were treated with convalescent plasma within three days being diagnosed died, while 12 percent of patients who were treated four days or more after being diagnosed died.