Researchers on Monday published preprint research that led to the U.K.'s decision to approve the steroid dexamethasone as a treatment for some severely ill COVID-19 patients. The U.K. had first shared preliminary findings from the trial last week. The study is in preprint form and has not been peer-reviewed, which is considered the gold standard in clinical research. However, during the coronavirus pandemic, preprints have become a popular way to more quickly release scientific data about the virus and potential treatments. The U.K.'s randomized study assessed the use of dexamethasone in 2,104 patients. An additional 4,321 patients received the standard of care. About 21.6% of the patients who received the steroid died, compared with 24.6% of the patients who had the standard of care. Of the patients who received the steroid who were on mechanical ventilators, 29.0% died, compared with 40.7% of patients on ventilators receiving the standard of care. And among patients receiving oxygen and dexamethasone, 21.5% died, as compared to 25.0% of patients who received oxygen and the standard of care. The drug did not benefit COVID-19 patients who were not receiving oxygen or ventilation in the study. The mean age of the clinical study's participants was about 66 years old; about two-thirds of patients in the trial were men; and about half of the patients who received dexamethasone had a pre-existing condition, such as diabetes or heart disease. "Dexamethasone provides an effective treatment for the sickest patients with [COVID-19] and, given its low cost, well-understood safety profile, and widespread availability, is one that can be used worldwide," the University of Oxford researchers concluded.