[BostonCard]

Here's a study that shows that the risk of death was actually more than twice as high in the hydroxychloroquine arm than in the usual care arm:

https://www.medrxiv.org/content/10.1101/...1.full.pdf

In this study, we found no evidence that use of hydroxychloroquine, either with or without azithromycin, reduced the risk of mechanical ventilation in patients hospitalized with Covid-19. An association of increased overall mortality was identified in patients treated with hydroxychloroquine alone.

That being said, there is a major problem with the study in that the study was not randomized, so it is possible, if not likely, that sicker patients were given hydroxychloroquine than those given usual care (confounding by indication).  From the article:

Our study has certain limitations including those inherent to all retrospective analyses such as non-randomization of treatments. We did, however adjust for a large number of Covid- 19-relevant confounders including comorbidities, medications, clinical and laboratory abnormalities. Despite propensity score adjustment for a large number of relevant confounders, we cannot rule out the possibility of selection bias or residual confounding.

So, I'm still going to wait till the WHO's or Novartis' clinical trials read out to determine whether HCQ is effective.  But we can probably rule out a "game-changing" effect size, or it would have overcome any confounding by indication.

BC

[BostonCard]

Here's a study that shows that the risk of death was actually more than twice as high in the hydroxychloroquine arm than in the usual care arm:

https://www.medrxiv.org/content/10.1101/...1.full.pdf

In this study, we found no evidence that use of hydroxychloroquine, either with or without azithromycin, reduced the risk of mechanical ventilation in patients hospitalized with Covid-19. An association of increased overall mortality was identified in patients treated with hydroxychloroquine alone.

That being said, there is a major problem with the study in that the study was not randomized, so it is possible, if not likely, that sicker patients were given hydroxychloroquine than those given usual care (confounding by indication).  From the article:

Our study has certain limitations including those inherent to all retrospective analyses such as non-randomization of treatments. We did, however adjust for a large number of Covid- 19-relevant confounders including comorbidities, medications, clinical and laboratory abnormalities. Despite propensity score adjustment for a large number of relevant confounders, we cannot rule out the possibility of selection bias or residual confounding.

So, I'm still going to wait till the WHO's or Novartis' clinical trials read out to determine whether HCQ is effective.  But we can probably rule out a "game-changing" effect size, or it would have overcome any confounding by indication.

BC