This is a very large retrospective study of patients around the world, showing an increased incidence of irregular heart rhythms in patients treated with CQ or HCQ compared to untreated patients. https://www.washingtonpost.com/health/2020/05/22/hydroxychloroquine-coronavirus-study/

The usual qualifiers apply: it's not a clinical trial, not randomized and not well-controlled, but the researchers did try to retroactively account for confounders like condition and disease state.

Once again, this is not a "causation" but a correlation and it is in line with what's already on the drugs' labels. Can everyone please calm down?

This whole thing is just bizarre and annoying. We have a long history with these drugs. We have been gathering safety information for decades.

The issue is really *not* whether they have side effects, or adverse events, or what those side effects/adverse events are. The issue is whether the efficacy outweighs the potential side effects/adverse events. So far, it doesn't appear to, but we need to finish clinical trials.

All of this hysteria is not helpful in the least.

I didn't mention the mortality data here because it's not impressive. The number of deaths is very low, so it's hard to measure real differences, and the authors were clear that "a cause-and-effect relationship between drug therapy and survival should not be inferred."

The other thing is there is no explanation offered for why the treatments might cause more death. The authors didn't investigate whether the increased mortality was attributable to increased cardiovascular events (I'm not sure why they didn't).

That, coupled with the caution that they might not have accounted for all confounders makes me very skeptical of the mortality data.