Many experts — including a scientist who worked on the Mayo Clinic study — were bewildered about where a key statistic came from.
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. Continue reading.