Convalescent plasma reduces the mortality of CoVID-19 by 35%, citizens of the United States were assured in a press conference on 23 August 2020, and the approval of this treatment for emergency use by the Food and Drug Administration (FDA) underscored that this constituted a breakthrough in treating the pandemic disease.
As usual, critical voices ventured to disagree. One physician reported that he had been using this treatment for a considerable length of time and had noted a perhaps marginal, certainly not great benefit for this intervention. Others pointed out that the use of convalescent plasma in general was nothing new.
That “35%” mortality reduction was emphasized a number of times in the televised official announcement. It was only a few days later that we learned that the original data suggested a reduction of mortality to about 8% from 11-12% for presumably comparable patients not so treated. In other words, 3 to 4% of patients may have derived a benefit in terms of decreased mortality.
Indeed, 8 is about 35% less than 11-12. However, a 3.5% reduction in mortality is nothing like a 35% reduction.
This episode illustrates what is quite commonplace as drug companies seek to impress doctors and patients with the wonderful benefits to be derived from their medications: relative effects rather than absolute ones are reported.
This is just one of the many things wrong with present-day practices in medicine, of course; dozens of works describing the dysfunctions are listed in my periodically updated bibliography.
Investigative reporters also revealed and that the FDA’s emergency use approval had come at the behest of the White House. Historians will recall that the whole science of genetics was derailed in the Soviet Union for a generation as Stalin’s administration enshrined as science the pseudoscience invented by Lysenko.
Skepticism about science and medicine 