Based on these two studies, it looks almost certain that hydroxychloroquine is at least as safe as a placebo for reducing symptoms [of COVID-19], and the drug probably reduces the incidence of symptoms by a little more than 10%.
The 10% is a relative reduction, not absolute. I don’t know how Scott Alexander defines “clinically significant”. Some authors thought that “significant” meant a 50% or 90% relative reduction in cases, although I personally think that a 10% reduction matters. But I have no medical experience and no medical training. If you read Stat News, you know more about medicine than I do.
I also conclude:
It seems that hydroxychloroquine probably brings down hospitalizations, but it’s unclear by how much.
And:
If you have to go to the hospital, stop taking hydroxychloroquine.
That fact comes from a large (n = 4716) randomized controlled trial, which found that hydroxychloroquine is almost certainly unsafe for treating patients who have been hospitalized with COVID-19. The drug caused about a 7% relative increase in deaths.
Bear in mind that I redid some of the statistics from the studies because I thought they were incorrectly concluding that hydroxychloroquine had no effect. If you don’t trust my math (I wouldn’t trust a stranger’s math), you can see my work here. And I wrote the post for an audience who might not know what Bayes is.
Last week I read the literature and concluded:
The 10% is a relative reduction, not absolute. I don’t know how Scott Alexander defines “clinically significant”. Some authors thought that “significant” meant a 50% or 90% relative reduction in cases, although I personally think that a 10% reduction matters. But I have no medical experience and no medical training. If you read Stat News, you know more about medicine than I do.
I also conclude:
And:
That fact comes from a large (n = 4716) randomized controlled trial, which found that hydroxychloroquine is almost certainly unsafe for treating patients who have been hospitalized with COVID-19. The drug caused about a 7% relative increase in deaths.
Bear in mind that I redid some of the statistics from the studies because I thought they were incorrectly concluding that hydroxychloroquine had no effect. If you don’t trust my math (I wouldn’t trust a stranger’s math), you can see my work here. And I wrote the post for an audience who might not know what Bayes is.