The much-criticized study on hydroxychloroquine and Covid-19 has now a dim outlook as the renowned medical journal The Lancet, which published it, distanced itself from it by admitting in a formal warning that “important issues” hung over it.
The Lancet wants “to alert readers that serious scientific questions about the study have been brought to (their) attention,” the magazine said.
The warning was issued on Tuesday night as an “expression of concern,” a formal statement used by scientific journals to indicate that a study is potentially problematic.
Although an “expression of concern” is not as far-reaching as a complete withdrawal, it is still likely to raise doubts.
The study in question concludes that hydroxychloroquine is not beneficial and may even be harmful to Covid-19 patients.
The study has had dramatic effects and consequences worldwide, including pressure on the WHO (World Health Organization) to stop clinical trials of hydroxychloroquine against Covid-19. Similarly, France has decided to ban this treatment.
The study published on 22nd May in The Lancet is based on data from 96,000 patients admitted to 671 hospitals between December and April and compares the status of those who received treatment with those who did not.
After its publication, many researchers expressed doubts about the study, including scientists who were skeptical about the value of hydroxychloroquine against Covid-19.
In an open letter published on 28 May, dozens of scientists from around the world stressed that the analysis of the Lancet study raises “methodological and data integrity issues”.
They list a long list of problematic issues, ranging from inconsistencies in the doses administered in some countries to ethical issues in the collection of information and the authors’ refusal to give access to the raw data.
The raw data was provided by Surgisphere, a US-based health data analysis company.
In its press release on Tuesday, The Lancet recalls that “an independent review of the origin and validity of the non-surgical data has been requested and is underway and results are expected very soon”.
“That’s not enough, we need a truly independent assessment,” researcher James Watson, one of the initiators of the open letter, responded to Twitter.
“There are doubts about the integrity of the Lancet study. In retrospect, it seems that policymakers placed too much trust in this document,” commented Professor Stephen Evans of the London School of Hygiene and Tropical Medicine.
Before the controversy over this study, other smaller-scale studies had come to the same conclusion without criticizing its methodology.
The Lancet study has also been strongly attacked by advocates of hydroxychloroquine, often with the keyword #LancetGate in social networks.
The French researcher Didier Raoult is at the forefront of this.
“The house of cards is collapsing,” tweeted Wednesday in response to the Lancet’s warning, after he had already called the study “imperfect”.
The authors, Dr Mandeep Mehra and his colleagues, are defending their study.
“We are proud to contribute to the work of Covid-19,” one of them, Sapan Desai, the head of Surgisphere, told AFP on May 29.
But this company is at the heart of all the issues. Another major medical journal, the New England Journal of Medicine (NEJM), also published a “statement of concern” on Tuesday about a study by the same team, conducted using Surgisphere databases.
The study did not focus on hydroxychloroquine, but on an association between mortality due to Covid-19 and heart disease.
A French expert, Professor Gilbert Deray, sees the publication of these warnings by The Lancet and NEJM as a sign that the two studies are “in the process of retraction”. In his opinion, such a rejection would be “a catastrophe”, as these journals are “references”.
“These false statements make it clear that scientific time must be separated from media time. The urgency of the pandemic does not justify mediocre studies,” he said on Twitter.