The New York Times reports:

At a news conference on Sunday announcing the emergency approval of blood plasma for hospitalized Covid-19 patients, President Trump and two of his top health officials cited the same statistic: that the treatment had reduced deaths by 35 percent.

Mr. Trump called it a “tremendous” number. His health and human services secretary, Alex M. Azar II, a former pharmaceutical executive, said, “I don’t want you to gloss over this number.” And Dr. Stephen M. Hahn, the commissioner of the Food and Drug Administration, said 35 out of 100 Covid-19 patients “would have been saved because of the administration of plasma.”

But scientists were taken aback by the way the administration framed this data, which appeared to have been calculated based on a small subgroup of hospitalized Covid-19 patients in a Mayo Clinic study: those who were under 80 years old, not on ventilators and received plasma known to contain high levels of virus-fighting antibodies within three days of diagnosis.

What’s more, many experts — including a scientist who worked on the Mayo Clinic study — were bewildered about where the statistic came from. The number was not mentioned in the official authorization letter issued by the agency, nor was it in a 17-page memo written by F.D.A. scientists. It was not in an analysis conducted by the Mayo Clinic that has been frequently cited by the administration.

“For the first time ever, I feel like official people in communications and people at the F.D.A. grossly misrepresented data about a therapy,” said Dr. Walid Gellad, who leads the Center for Pharmaceutical Policy and Prescribing at the University of Pittsburgh. [Continue reading…]

I have been criticized for remarks I made Sunday night about the benefits of convalescent plasma. The criticism is entirely justified. What I should have said better is that the data show a relative risk reduction not an absolute risk reduction.

— Dr. Stephen M. Hahn (@SteveFDA) August 25, 2020