The reports, published in two leading journals, were retracted after authors could not verify an enormous database of medical records.
"The studies, published in renowned scientific journals, produced astounding results and altered the course of research into the coronavirus pandemic.
One undercut President Trump’s claim that certain antimalarial drugs cure Covid-19, the illness caused by the virus, concluding that the medications in fact were dangerous to patients. The other found that some blood pressure drugs did not increase the risk of Covid-19 and might even be protective.
Both studies were led by a professor at Harvard, and both depended on a huge international database of patient medical records that few experts had ever heard of.
But on Thursday, the studies were retracted by the scientific journals in which they had appeared, The New England Journal of Medicine and The Lancet, because the authors could not verify the data on which the results depended."