A major study detailing the harmful effects of hydroxychloroquine (HCQ) on COVID-19 patients has drawn flak from researchers and academicians across the world. Over 120 experts signed an open letter challenging the findings that said HCQ increased the chances of death or serious cardiac complications in COVID-19 patients.

The study analyzed data from 15,000 COVID-19 patients who had received the drug with or without antibiotics and compared the data to 81,000 patients who did not receive the drug. It was a retrospective, observational study meaning that it looked for associations and not causal links.

(Read more: Lancet study with 96,000 COVID-19 patients shows hydroxychloroquine does more harm than good)

Hydroxychloroquine is, of course, approved for use in the treatment of malaria and certain autoimmune diseases. Now, doctors and scientists are looking into its potential to fight COVID-19.

What are the criticisms?

The major criticisms of the study include an inadequate adjustment for known and measured confounders (such as age, smoking habits, comorbidities, etc.), the absence of an ethics review, and the fact that the dataset has not been made public. Patient data disaggregated by the hospital is not available, let alone individual patient data that could explain some of the findings—at least in part. 

The data from Australia was also questioned; the number of cases and deaths contradicted official counts. This has since been amended—the researchers said that this was because of an error that included an Asian hospital with the Australian sample. The data from Africa also seems to suggest that 40% of the deaths took place in sophisticated hospitals that were linked to the study—this figure also seems to be too high, according to the scientists who wrote the letter. 

Further, the dosage of HCQ has also been questioned, and there also seems to be unusually small reported variances in baselines variables, interventions, and outcomes between the continents. 

The findings of the study published in The Lancet have temporarily stopped clinical trials involving HCQ across the world, including in the HCQ arm of the WHO Solidarity trials.

The critics of the study want randomised control trials (RCTs) to go on since this is the only way to know with authority if the drug has any effect or not. Researchers who conducted the study have seconded this and said RCTs remain the gold standard, and have also allowed an independent review of the data. 

The study got the data from Surgisphere, a company based in Chicago. The company said it cannot reveal the data because of privacy agreements signed with the hospitals. 

India's decision to use hydroxychloroquine for COVID-19

Separately, the Director-General of the Council of Scientific & Industrial Research (CSIR), Dr Shekhar Mande, said that the study does not provide compelling evidence to stop the administration of HCQ. He noted that it was a database study, so one cannot say that HCQ was the cause of the higher likelihood of mortality.

Indeed, the Indian Council of Medical Research or ICMR continues to recommend the use of HCQ along with azithromycin preventively for contacts of patients and frontline workers. The Ministry of Health and Family Welfare also wrote to the WHO questioning the decision to stop the HCQ trials. 

(Read more: When is HCQ used for COVID-19?)

While there is data to show that the drug can cause complications, especially in high doses and to those with certain pre-existing conditions, more randomized control studies are needed to understand the therapeutic effects of HCQ for COVID-19 patients.

Doctors for Lancet study on hydroxychloroquine raises questions; ICMR stands by its decision to use the drug for COVID-19
Dr Rahul Gam

Dr Rahul Gam

Infectious Disease
8 Years of Experience

Dr. Arun R

Dr. Arun R

Infectious Disease
5 Years of Experience

Dr. Neha Gupta

Dr. Neha Gupta

Infectious Disease
16 Years of Experience

Dr. Anupama Kumar

Dr. Anupama Kumar

Infectious Disease


Medicines / Products that contain Lancet study on hydroxychloroquine raises questions; ICMR stands by its decision to use the drug for COVID-19

References

  1. Mandeep Mehra, et al. Hydroxychloroquine or chloroquine with or without a macrolide for treatment of COVID-19: a multinational registry analysis The Lancet, May 22, 2020.
  2. Surgisphere [Internet]. Surgisphere Corporation. Chicago, USA; Follow up on our Lancet paper
  3. Document Cloud [internet]. Document Cloud; Concerns regarding the stastical analysis and data integrity.
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