After our live interview on GB News on our findings of the UKHSA review, one of the two anchors, Philip Davies MP, received the following communiquè from the UKHSA:
Dr. Renu Bindra, Deputy Director of Public Health Clinical Response at UKHSA, said:
“The current evidence on face coverings suggests that all types of face coverings are, to varying extents, effective in reducing transmission of respiratory viruses in both healthcare and community settings. N95 respirators are likely to be the most effective, followed by surgical masks, and then non-medical masks, although optimised non-medical masks made of two or three layers might have similar filtration efficiency to surgical masks.
“The evidence specific to COVID-19 is still limited and does not allow for firm conclusions to be drawn for specific settings and types of face coverings. However, there is no evidence to suggest that face coverings and masks would be less effective at preventing the transmission of COVID-19 than any other similar respiratory infection.”
BACKGROUND
Throughout the pandemic, UKHSA published several rapid evidence reviews and a statement from an expert panel informed by review-level evidence (available here).
In the most recent version, review (update 2), studies were assessed by experienced reviewers using a risk of bias tool, which can be applied to most study designs (observational and interventional). In all three evidence reviews of the effectiveness of face coverings, all biases the reviewers felt were present were detailed in the supplementary tables and limitations were reported throughout, as well as in the conclusions and main messages.
In the overview of evidence conducted for the expert panel, reviews were assessed using AMSTAR 2, and key findings were given a confidence rating by combining the overview of evidence with expert knowledge and experience.
The most recent ‘Living with COVID-19’ guidance states that COVID-19 should be managed like other respiratory infections and only recommends face coverings for those with symptoms of a respiratory infection, who have a high temperature or feel unwell and are unable to avoid contact with others.
We appreciate John McCarthy’s comment: “Why do you waste your time on such nonsense?“
However, we take officialdom and responsibility seriously. So we read and reread Dr. Bindra’s message to make sense of it – but we were defeated, much like Mr. McCarthy foresaw.
Let’s start off in order of nonsense. The first statement says:
The current evidence on face coverings suggests that all types of face coverings are, to varying extents, effective in reducing transmission of respiratory viruses in both healthcare and community settings. N95 respirators are likely to be the most effective, followed by surgical masks, and then non-medical masks, although optimised non-medical masks made of 2 or 3 layers might have similar filtration efficiency to surgical masks. (emphasis added)
In contrast, our Cochrane review reports:
We are very uncertain on the effects of N95/P2 respirators compared with medical/surgical masks on the outcome of clinical respiratory illness N95/P2 respirators compared with medical/surgical masks may be effective for ILI… ‘The use of a N95/P2 respirators compared to medical/surgical masks probably makes little or no difference for the objective and more precise outcome of laboratory‐confirmed influenza infection.’ (emphasis added)
As the source of Dr. Bindra’s statement is not cited, we are at a loss to explain the source of such certainty.
However, here comes the bizarre bit. On April 14th, the Daily Telegraph reported: “A rapid review report published by the UKHSA investigated if high-quality masks, such as the N95, KN95 and FFP2 coverings, protect clinically vulnerable people in the community from catching Covid.”
The UKHSA rapid Review reported:
The purpose of this rapid review was to identify and assess the available evidence for the effectiveness of N95 and equivalent face masks as wearer protection against coronavirus (COVID-19) when used in the community by people at higher risk of becoming seriously ill from COVID-19 (search date: up to September 26th 2022). The review did not identify any studies for inclusion, and so could provide no evidence to answer the research question. (emphasis added)
And then Dr. Aodhán Breathnach, a Consultant Global Health Microbiologist at UKHSA and a Consultant Medical Microbiologist at St George’s University Hospitals recently published a study which found masks in hospitals had little impact on Covid transmission in the Omicron wave. He told the Telegraph: “In my view, there is no good evidence that N95 masks work any better than surgical masks.”
So what were Dr. Bindra’s statements based on?
The second paragraph of the statement is even more peculiar:
The evidence specific to COVID-19 is still limited and does not allow for firm conclusions to be drawn for specific settings and types of face coverings. However, there is no evidence to suggest that face coverings and masks would be less effective at preventing the transmission of COVID-19 than any other similar respiratory infection.
If the evidence relating to Covid is limited, it is because governments, public health bodies, foundations and so on refuse to carry out good quality studies to answer the question.
There is also a subtler point: the statement assumes SARS-CoV-2 transmission is different from that of all the other respiratory agents. However, we do not know this because good quality investigations based on molecular epidemiology methods have not been carried out on the transmission of other agents such as rhinoviridae, influenza or human metapneumovirus.
Dr. Bindra’s Background continues the series of puzzling contradictions:
Throughout the COVID-19 pandemic, UKHSA published a number of rapid evidence reviews and a statement from an expert panel informed by review-level evidence (available here).
The link takes us to a page where the evidence of “face coverings” is out of date. The first review in the list is September 2021, which contains no convincing evidence of anything, as we have pointed out, study by study.
In the most recent version of the rapid evidence review (update 2), we pointed out that no included observational study had a protocol, analyst blinding or gave a clear definition of COVID-19.
In the overview, evidence was given a confidence rating by combining the overview of evidence with expert knowledge and experience. This is expert-level spin, as expertise is at the bottom level of evidence as it is opinion. A perusal of the panel report shows that it met three times: “The panel met three times on March 1st 2021, April 21st 2021 and May 12th 2021.” The conclusions are out of date, although the UKHSA website reports it was updated to March 31st 2023.
Perhaps the most ludicrous statement is: “It should also be noted that the most recent ‘Living with COVID-19’ guidance specifically states that COVID-19 should be managed like other respiratory infections and only recommends face coverings for those with symptoms of a respiratory infection, who have a high temperature or feel unwell, and are unable to avoid contact with others.”
It is in direct contradiction to what is in paragraph one, in which the claim that all types of face coverings are, to a greater or lesser extent, responsible for lowering the risk of infection.
So what can we conclude? The UKHSA statement is an opinion; it is poorly thought through, and it certainly isn’t based on the evidence. It is based on evangelism which is eroding what is left of trust in science.
When it comes to informing public health, who should we then trust?
Dr. Carl Heneghan is the Oxford Professor of Evidence Based Medicine and Dr. Tom Jefferson is an epidemiologist based in Rome who works with Professor Heneghan on the Cochrane Collaboration. This article was first published on their Substack blog, Trust The Evidence, which you can subscribe to here.
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