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Does Hydroxychloroquine Work?

So what is really going on with hydroxychloroquine (HCQ)? There are lots of conflicting studies pointing to one conclusion or the other. It is worth reviewing how the sausage is made. The gold standard is a randomized double-blind study with a large N, where participants are randomly put into two groups. One is given a placebo and another is given the treatment. Measurements are taken and effects are observed. Various things are controlled for like age and gender.

If the treatment is better than chance it is considered effective. Though effects can be weak, moderate, or strong. Ideally, strong is what you want meaning it is much, much, much greater than chance. Then the results are published and hopefully replicated. When all that happens we can say the treatment is better than chance and start using it.

This is considered to be the best kind of study design. 

Then there is the issue of measurement. How do you measure the HCQ effect? Do you ask patients how they feel? Do you count the number of breaths they can do on their own? Do you look at fatalities? Time spent in the hospital? Something else?

Besides measurement, you need to have a large N, or population. 10 people won’t cut it but 10,000 might. 

There are variables to consider such as the type of population (old people vs. young as an example), the degree of COVID (mild, moderate, strong), the dosage amount, how many doses, where they are along with the disease (the start vs the end), and what else you add with HCQ such as AZ. There might also be variables that we don’t know about. 

Lastly, HCQ has anti-viral, anti-inflammation, and anti-thrombotic properties. It is hard to tease out what about HCQ is helpful.

The NIH and WHO studies were stopped because the data in their design showed the drug to be ineffective. That doesn’t mean HCQ works or doesn’t work only it didn’t with their design. Other studies were stopped because HCQ was causing cardiac issues which makes sense because the kinds of people who end up in a hospital for COVID are older and/or have underlying health issues which are exacerbated with an HCQ treatment. 

It is probably likely that HCQ has some kind of benefit but under what circumstance and for who exactly is not known.

However, it is infuriating that scientists will often make loud proclamations about what works or doesn’t, rather than letting the evidence decide and the peer review process plays out.

Let’s use one as an example. Harvey Risch published an opinion piece in a July 2020 Newsweek titled: The Key to Defeating COVID-19 Already Exists. We Need to Start Using It. In it, he argues that he should be using Hydroxychloroquine.

However, the argument has major flaws outlined below. Just because a Yale Dr publishes an opinion piece in Newsweek does not mean it is free of bad arguments.

1. The opinion piece cherry-picks studies. I mean I could cherry-pick all the negative studies which show it doesn’t work. Indeed, one of the studies he alludes to from Gautret et al 2020 could be fraudulent. Some data used in that study appears to not exist.

Dahly et al. 2020 in their preprint article called: Statistical review of Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open-label non-randomized clinical trial (link to pdf) provide an extensive and exhaustive review of Gautret et al 2020.

2. The studies he cites do not use the gold standard, ie: Studies that are double-blind randomized ones. He even mentions this in his own study.

3. He is arguing that the drug works only at the start of the disease but if it strongly inhibits coronavirus replication, there’s no reason that it couldn’t be effective both in the middle/end of the disease and at the start.

4. The author fails to point out the alternative rival hypotheses that caused the Swiss deaths to revert. It is sad to see a Dr. fail to understand correlation is not causation.

This article: Hydroxychloroquine to treat COVID-19: Evidence can’t seem to kill it is a good rebuttal of that Newsweek Opinion piece and goes into more detail of those four points.

For further review of HCQ studies see

For papers that have been retracted, see: