This is where I am putting all of the studies and other data that I have found on the use of hydroxychloroquine to treat Covid-19. I don't claim that this is a complete list, and I welcome additional information. I am also not vouching for the quality of any of these. This is obviously a huge topic, and this post is not meant to be an analysis, but just a starting point for those who want to look at the research that has been done so far. I am aiming to make this as comprehensive a list as possible, while highlighting those studies that have either had the most impact or are the most valuable, and providing links to critiques of studies where they exist. I do NOT plan to update this ongoingly, although if something incredibly significant happens, or if I've left out something important (which I probably have), I may add it here. For a more updated accounting of studies that have been done, see this list, which I also mention below.
I. Studies showing that hydroxychloroquine is NOT effective (or is dangerous) against Covid-19:
1. Notably, the study (published in the Lancet) that has perhaps had the most impact on research, treatment protocols, and public perception, was retracted after independent researchers found that it was based on data that did not appear to exist.
2. The VA study, from April, that 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." (For Didier Raoult's critique of this study, see here.)
3. This study, which did NOT look at hydroxychloroquine, but at chloroquine (which is known to be more toxic than hydroxychloroquine), but which I am including here as some may bring this up as an argument against hydroxychloroquine. It is not.
4. The Oxford Recovery trial, which has been widely criticized for using doses of HCQ that were dangerously high.
5. The Solidarity trial, conducted by the World Health Organization "and partners", which like the Recovery trial, used excessively high dosing.
II. Lists of studies showing that it IS effective (including collections of studies showing both positive and negative outcomes):
1. This is probably the most comprehensive listing of studies, and is being continuously updated. As of August 6, it lists 67 studies, 75% showing positive results (100% of the studies that examined HCQ given early in the course of illness, showed positive results.)
2. Another good list: Sequential CQ / HCQ Research Papers and Reports January to April 20, 2020. Executive summary:
"The HCQ-AZ combination, when started immediately after diagnosis, appears to be a safe and efficient treatment for COVID-19, with a mortality rate of 0.5%, in elderly patients. It avoids worsening and clears virus persistence and contagious infectivity in most cases."
3. The White Paper from Dr. Simone Gold, discussing both safety studies and efficacy studies in support of HCQ to treat Covid-19.
4. The paper by Dr. James Todaro and Gregory Rigano on March 13, 2020, "An Effective Treatment for Coronavirus (COVID-19)", which was taken down by Google Docs (and later put back up), in support of HCQ to treat Covid-19.
5. A paper from May 27, by Yale epidemiologist Harvey Risch, analyzing five studies and finding "clear-cut and significant benefits to treated patients." Risch's paper also examined studies showing HCQ's safety.
III. Some of the more notable studies showing positive results (by notable, I don't mean that I am endorsing any of the studies or their results, only that they are some that have received the most attention):
1. Study by Didier Raoult et al: Hydroxychloroquine and azithromycin as a treatment of COVID-19: results of an open- label non-randomized clinical trial. I believe this was the first study on the treatment to hit the news, and it was conducted by a team led by Didier Raoult, one of the world's foremost experts on communicable diseases (listed here as the number one expert worldwide.)
Raoult has continued to treat Covid-19 patients at his institute with HCQ, and continues to report on the results, here. And DAILY updates on their numbers are published here.
2. The Zelenko study. This was a retrospective study involving 141 patients, looking at early treatment with the triple therapy of hydroxychloroquine, zinc and azithromycin. The study found that this therapy was associated with "...significantly less hospitalizations and 5 times less all-cause deaths."
3. Chinese study, April 10 2020. "Efficacy of hydroxychloroquine in patients with COVID-19: results of a randomized clinical trial." This randomized study, involving 62 patients, found that HCQ could "significantly" improve outcomes.
III. Country data:
1. From this piece in Newsweek, by Yale epidemiologist Harvey Risch:
"...we have seen what happens in large populations when these drugs are used. These have been "natural experiments." In the northern Brazil state of Pará, COVID-19 deaths were increasing exponentially. On April 6, the public hospital network purchased 75,000 doses of azithromycin and 90,000 doses of hydroxychloroquine. Over the next few weeks, authorities began distributing these medications to infected individuals. Even though new cases continued to occur, on May 22 the death rate started to plummet and is now about one-eighth what it was at the peak.
"A reverse natural experiment happened in Switzerland. On May 27, the Swiss national government banned outpatient use of hydroxychloroquine for COVID-19. Around June 10, COVID-19 deaths increased four-fold and remained elevated. On June 11, the Swiss government revoked the ban, and on June 23 the death rate reverted to what it had been beforehand. People who die from COVID-19 live about three to five weeks from the start of symptoms, which makes the evidence of a causal relation in these experiments strong. Both episodes suggest that a combination of hydroxychloroquine and its companion medications reduces mortality and should be immediately adopted as the new standard of care in high-risk patients."
2. Related to what Risch says above, there is this:
3. Near the end of this very long piece, which is also very much worth reading, by Filipe Rafaeli, is a rundown of the experiences of several countries and states that have used HCQ widely, including: Malaysia, Russia, Turkey, UAE, South Dakota, New Brunswick CA, Costa Rica, Morocco, India and Kazakhstan.
The segment finishes with this graph: