Research ExplainedEasy to understand, visual summaries of the latest research studies.

This is a summary of "Outcomes of hydroxychloroquine usage in United States veterans hospitalized with Covid-19"


Does hydroxychloroquine (HCQ) affect whether COVID-19 patients needed a ventilator or died?

Based on a national retrospective study of hospitalized VA patients, hydroxychloroquine (HCQ) did not reduce COVID-19 deaths and should be prescribed with great caution.

Key takeaways

Why is this important?

Political leaders, including President Trump, have touted hydroxychloroquine as a promising treatment after an early French study appeared to show impressive results in COVID-19 patients. However, that study has been heavily criticized for not including a control group in its experimental design. Without a control group, we have no way to tell whether patients recovered due to the drug or on their own. As a result, we have to take that study’s conclusions with a heavy dose of skepticism.

However, despite the flawed evidence, people have started treating themselves with hydroxychloroquine or one of its chemical cousins, believing it will protect them from COVID-19. This has led to at least one instance of death and a shortage for those who actually need the drug for conditions including lupus and rheumatoid arthritis.

Combating rumors with solid evidence could have important medical consequences and save lives. This study is a preliminary but strong step towards understanding the actual impacts of hydroxychloroquine on COVID-19.

What did the study do?

How was it reported?

The original paper is a preprint study. It has not been certified by peer review from other researchers, and information presented may be erroneous. Do not use it to guide clinical practice! Learn more →

Original Paper DOI10.1101/2020.04.16.20065920

Outcomes of hydroxychloroquine usage in United States veterans hospitalized with Covid-19 [PDF]


  1. U.S. Department of Veterans Affairs
  2. This could actually be helpful given COVID-19 has disproportionately hit African-American communities.
  3. Some people were speculating that the two drugs would work better together.
  4. This is known as a hazard ratio. Numbers presented here are based on the adjusted hazard ratio of the outcomes of death or being placed on a ventilator relative to the reference group of "No HCQ." For more detailed information, including 95% confidence intervals and p values, please see the source paper.

Updates and Corrections

If you see a mistake or want to suggest changes, please contact us.

Share This Explanation

Copy Link Twitter Facebook LinkedIn


Like this explanation? Get notified when we post new ones!

Please enter a valid email address.

👍 You're all set!