(CNN) A new study finds hydroxychloroquine, the drug touted and taken by President Trump, is linked to a higher risk of death in coronavirus patients.
The large observational study was published Friday in the medical journal 'The Lancet.'
It found seriously ill COVID-19 patients who were treated with hydroxychloroquine and chloroquine were more likely to die or develop dangerous heart arrhythmias.
The study looked at more than 96,000 COVID-19 patients on six continents. It was not a rigorous test of hydroxychloroquine or chloroquine, but is by far the largest look at their use in real world settings.
Nearly 15,000 of them were treated with one of the two anti-malarial drugs, or one of those drugs combined with an antibiotic.
All four of the treatments were linked with a higher risk of dying in the hospital. Researchers estimate that the death rate attributable to use of the drugs, with or without an antibiotic, is roughly 13% versus 9% for patients not taking them.
Serious abnormal heart rates were also more common among patients receiving any of the four treatments.
Dr. Deborah Birx responded today at the White House to the newly released study on hydroxychloroquine and death rates.
"I think the FDA has been very clear on their website about their concerns about hydroxychloroquine, particularly when it is combined. I think you see that in the study," Birx said. "I tell you what I take home from the Lancet study...it clearly shows that comorbidity that puts individuals at more risk."