Professor: Large Danish mask study rejected by three top journals
The researchers behind a large and unique Danish study on the effect of wearing a mask have great difficulties in getting their research results published. One of the participating professors in the study concedes that the still secret research result could be considered ‘controversial’.
Update November 18, 2020: The Danish study has now been published.
Author: Lars Henrik Aagaard; Published: October 22, 2020
Original article: Berlingske.dk (Danish newspaper)
For weeks, media and researchers all over the world have been awaiting the publication of a large Danish study on the effect – or lack thereof – of walking with facemasks in public spaces during the corona pandemic.
Now one of the researchers involved in the study can report that the finished research result has been rejected by at least three of the world’s leading medical journals.
These are The Lancet, The New England Journal of Medicine and the American Medical Association’s journal JAMA.
“They all said no,” says Professor, MD and chief medical officer at the research department at North Sealand Hospital, Christian Torp-Pedersen.
However, the professor does not wish to provide the justification given by the journals.
“We cannot begin to discuss what they are dissatisfied with, because if we did, we also have to explain what the study showed, and we do not want to discuss it until it is published,” explains Christian Torp-Pedersen.
The study was launched at the end of April following a grant of 5 million kroner from the Salling Funds. It involved as many as 6,000 Danes, half of whom had to wear facemasks over a longer period of time in public spaces. The other half was selected as a control group.
A larger proportion of the test participants were employees of Salling Group’s supermarkets: Bilka, Føtex and Netto.
The study and its size are unique in the world, and the aim was once and for all to try to clarify the extent to which the use of facemasks in public spaces provides protection against corona infection.
For the same reason, the researchers behind the study have regularly received inquiries from both Danish and international media with queries as to when the results are available. In the research world, it is good practice not to comment on a research result until it has been published in a recognised so-called peer review journal.
However, the question of publication was approached by another of the study’s participating researchers, professor at Hvidovre Hospital’s infectious disease department, Thomas Lars Benfield, on Sunday. It happened in an email shared on Twitter by former New York Times journalist Alex Berenson. The professor’s answer:
“As soon as a journal is brave enough to accept the study.”
Thomas Lars Benfield does not wish to elaborate in detail on what he means by the fact that a journal must be ‘brave’ to publish the study. However, he writes in an email to Berlingske:
“The quote is a bit out of context. The article is being reviewed by a respected journal. We have decided not to publish data until the article is accepted.”
However, Thomas Lars Benfield’s co-researcher on the study, Christian Torp-Pedersen, says that he “might have answered the question in a similar way as Benfield did”.
Does this mean that your research result may be perceived as controversial in some people’s eyes?
“That’s how I would interpret it, too.”
Can a controversial research result be interpreted as not demonstrating any significant effect of mask use in your study?
“I think it’s a very relevant question you’re asking.”
It must be up to the readers themselves to judge what should be put into these answers.
However, if the Danish research result is indeed “controversial”, and if it is believed that no evidence has been found of any major effect of facemask use in public spaces, it will be highly spectacular.
For in that case, one must question the expediency of the fact that the vast majority of the world’s population currently walks around with a mask in their pocket or on their face.
But of course it cannot be ruled out that the three medical journals take the view that the data base in the Danish study is flawed – that, for example, there are too few corona-infected people in the study to be able to draw clear conclusions about the protective effect of masks on infection with the new virus.
In this context, it is worth noting that the study was carried out predominantly in May, when the pressure of infection at home [in Denmark] was greatly decreasing.
“This is the world’s largest study of its kind and it is expected to be an important factor in the basis of regulatory decisions regarding mask use.”
Henning Bundgaard, Professor and Chief Medical Officer, Rigshospitalet
The study’s spokesman and lead author is Professor of Cardiology and Chief Physician at Rigshospitalet [i.e. the Copenhagen University Hospital], Henning Bundgaard. He strongly stresses that he wants to be in charge of research ‘of high quality’.
But the professor cannot enter into a discussion about what the study might show or relate to the information Berlingske has received from other study authors.
However, he explains that he is ‘sorry’ that the study has not yet been published in a peer review journal. That is, in a journal where research results are assessed by independent peers in the field.
“This is the world’s largest study of its kind and it is expected to be an important factor in the basis of regulatory decisions regarding mask use – not only in Denmark – but everywhere. That’s why the publication is urgent – and we’re doing what we can on our part,” he says, continuing:
“If I wanted to publish things outside of a journal, I would have done it a long time ago. But there are a whole host of scientific reasons why I don’t. The research I want to do must be of high quality, and this means, among other things, that other researchers must be able to see my data before publication and look through calculations and statistics in order to assess whether they come to the same conclusion as us. This is an essential quality criterion for good research.”
Henning Bundgaard also explains that the study only illuminates the extent to which masks protect mask carriers from infection. In other words, it does not illuminate the opposite side of infections – whether people who walk without a mask near an infected mask carrier are at reduced risk of becoming infected with coronavirus.
“But I don’t think that such a study can be conducted,” the professor says, adding:
“In that case, you had to take someone who was documented to be infected and carried the virus, and then you had to let one half go with a mask and the other without a mask. Next, in their environment, one had to measure how many became ill and how many did not become ill. For example, it would be colleagues and families and those on the bus and in shops. It would be terribly unethical and would – as far as I can see – never be implemented.”
Early during the corona pandemic, it was shown that in some cases infection can occur from individuals before obvious symptoms have arisen. Also, infected people who never get symptoms can in some cases infect others with the new coronavirus.
The masking journey
At home, the Danish Health and Medicines Authority was very long dismissive of the use of face masks in public spaces – even though a large number of countries south of the border already in the spring made masks mandatory in shops and public transport.
For example, Søren Brostrøm, Director of the Danish Health and Medicines Authority, said as recently as 29 July, according to DR:
“Masks make no sense in the current situation where we still have a very low infection in Denmark.”
But on 15 August, when Prime Minister Mette Frederiksen (Social Democrat) launched a nationwide mandate to use masks in public transport, the tone was different at the director.
“We have learned this ourselves,” he said, adding that masks “have an effect on the vulnerable.”
At the beginning of the pandemic, the World Health Organisation (WHO) also expressed some doubts, saying, among other things, that there is insufficient evidence that it makes sense for healthy people to wear a mask.
However, on 6 June the WHO changed its position, including the following statement from Director-General Tedros Adhanom Ghebreyesus:
“In light of new research, the WHO recommends that governments should encourage the public to wear masks in places with many people and where social distance is difficult to observe.”
The research he was referring to was in particular a WHO-funded so-called metastudy in The Lancet, in which researchers concluded that masks have appeared to be protective for “people in public spaces exposed to infection”.
[Note by SPR: The WHO meta-study has been shown to be seriously flawed.]
Berlingske has previously interviewed one of the world’s leading experts on the efficacy of wearing masks, professor and head of Hong Kong University’s department of epidemiology and biostatistics, Benjamin Cowling. His overall assessment reads as follows:
“Based on all available evidence, I believe that the broad and correct use of facemasks in society reduces the infection by between 10 and 20 percent.”
In other words, the completely watertight and unambiguous evidence of a protective effect of facemasks in public spaces is still lacking. The big question now is whether Danish researchers are able to deliver it.
There is no word yet on when a journal will accept the Danish research result and publish it – after which the public can gain more knowledge.