Researchers behind a large study on the that examined the risks and benefits of using the anti-malaria drug hydroxychloroquine as a potential treatment for Covid-19 are now posting corrections to the study, after more than 180 scientists expressed concerns over inconsistencies in some of the data used for the research.

What new data reveals about two much-hyped experimental Covid-19 treatments

Study shows link between hydroxychloroquine and increased risk of death

Last month, The Lancet published a study that showed the anti-malaria treatment hydroxychloroquine, which has been widely touted by President Trump as a potential treatment for Covid-19, was linked with an increased risk of death among Covid-19 patients.

The study found that hospitalized Covid-19 patients who were treated with the anti-malaria drugs hydroxychloroquine or chloroquine, either alone or in combination with a macrolide, were associated with an increased risk of death and increased risk of developing ventricular arrhythmias.

The study—which was based on data on 96,000 hospitalized Covid-19 patients reported by 671 hospitals across six continents from Dec. 20, 2019, to April 14, 2020—is the largest to date to examine the risks and benefits of treating Covid-19 with the antimalarial drugs.

Based on the study's findings, the World Health Organization (WHO) last week announced that it was temporarily suspending a global trial evaluating the safety and effectiveness of hydroxychloroquine as a treatment for Covid-19.

Scientists raise concerns about the study

However, in an open letter to The Lancet's editor, Richard Horton, and the study's authors, more than 180 scientists and physicians from around the world expressed several concerns over inconsistencies in the data used for the study, as well as concerns over the method that researchers used to analyze the data.

For example, the scientists and physicians claimed there were discrepancies between data included in the study that was linked to Australian patients and data that was separately reported by the Australian government. In addition, the scientists and physicians raised concerns that the study's authors may have inadequately adjusted their analysis for certain variables, such as side effects associated with drugs and the doses of the drugs given to patients.

The scientists and physicians also criticized the study's authors for failing to release the raw patient data used for the study and information about which hospitals and countries provided the data.

David Boulware, an infectious-disease physician who signed the letter, said it is standard for researchers to make available the raw data used for studies. "That's the best practice, to have a de-identified data set available, so other people could replicate their results," Boulware said. "There's this whole issue of transparency."

Further, the scientists and physicians in the letter asked The Lancet and Surgisphere, the company that compiled the information database for the study, to make available the peer-review process that led to the study "being accepted for publication."

The Lancet, study authors, and Surgisphere respond

After the letter's release last week, The Lancet on Friday posted a correction stating that the study had incorrectly reported the number of patients included in the study from Asia and Australia. In the correction, the research team behind the study updated the data from Australia and Asia and an appendix they had included in the study. The researchers said the data discrepancy did not affect the study's findings.

Mandeep Mehra, a physician at Brigham and Women's hospital and lead author of the study, in a statement said The Lancet this week informed the authors of a discrepancy in the Australian hospital data, leading the authors to discover that data from a hospital in Asia had been incorrectly incorporated into the data from hospitals in Australia, but that the error did not affect the study's conclusions.

Separately, Surgisphere said the data it received from hospitals for its database is anonymized, and the company therefore cannot identify which hospitals reported the data. Sapan Desai, the owner and founder of Surgisphere, added that the company has "not found any" additional "valid criticism" in the open letter "that hasn't already been addressed" either by the correction published in The Lancet or by a response that was published on Surgisphere's website (Hopkins, Wall Street Journal, 5/29; Axelrod, The Hill, 5/29; Rabin, New York Times, 5/29).