After months of hyping stories about how hydroxychloroquine was either ineffective for treating COVID-19 or dangerous or both, CNN had to face the inconvenient reality last week that a study by the respected Henry Ford Health System in Michigan reduced the number of fatalities from that virus. So what to do? Well, one answer was to cast aspersions upon that study which is what CNN's senior medical correspondent Elizabeth Cohen did last Friday.  JIM SCIUTTO: OK, let's talk about hydroxychloroquine. So many claims have been made including by the president of how effective this is, and a lot of studies have shown no effect. There are even some studies that show that it has a negative effect for patients. But there's a new study that shows that for some people as an early treatment, it may help. Well, how broad is this and for who exactly? ELIZABETH COHEN: Right, so this is just one study showing that it worked. Let's talk a minute about  the studies that didn't show, that showed that it didn't work. There were two studies similar to this one that showed that it didn't work, and there were two clinical trials, one in the U.S. and one in the U.K., that ended early because it showed that it didn't work. The one in the U.K. was on 11,000 patients. That is a lot of evidence showing that hydroxychloroquine doesn't work. This is really the first major study of its kind, showing that it does work. The authors who were at the Henry Ford Health System in Detroit say it's because they were smart and they gave it early, they didn't give it to people, you know, at death's door. That's not where they were headed, they gave it to people earlier than other people did. However, I spoke to some of those other hospitals and they said, oh, that's not true. We gave it really early as well. So that may not be the reason. Something that is a little disturbing about this study, according to experts I've spoken to, is that they excluded more than 260 patients from the study because they were still in the hospital at the time they ended the study. To get an idea of Cohen's past eagerness to portray hydroxychloroquine as a dangerous treatment for COVID-19, take a look at this Trump-obsessed May 22 article she co-authored,  "Large study finds drug Trump touted for Covid-19 is linked to greater risk of death and heart arrhythmia." Seriously ill Covid-19 patients who were treated with hydroxychloroquine or chloroquine were more likely to die or develop dangerous irregular heart rhythms, according to a large observational study published Friday in the medical journal The Lancet. President Donald Trump has been a frequent cheerleader for a combination of the antimalarial hydroxychloroquine and the antibiotic azithromycin as a Covid-19 treatment. He promoted the drugs nearly 50 times, despite pleas from scientists to let studies decide if the treatment worked or not. On Monday, Trump said he was taking hydroxychloroquine to prevent coronavirus infection, although there's no evidence it can do that. A big problem for Cohen was that on the very same day that she hyped that study, The Lancet had to retract it. ...OOPS!