How might strong advocates of community masking – who happen to occupy positions within the hierarchy that provide opportunities to influence research activity – go about achieving their aims? I suggest it would include some combination of discouraging the undertaking of robust research about mask effectiveness and potential harms, impeding and delaying the publication of unfavourable findings, and undermining the value of rigorous empirical science. A look at the history of the Cochrane mask reviews seems to offer an illuminating case study of these insidious forces in action.
Cochrane reviews are widely recognised to provide the most authoritative and comprehensive evaluation of the scientific evidence regarding specific healthcare interventions, and their raison d’être is to inform the decision-making process. On January 30th 2023, the latest version of the Cochrane review of the effectiveness of physical interventions (including masks) in reducing the spread of respiratory viruses was published. In keeping with their earlier reviews, the overarching conclusion of the authors confirmed what we already knew: masks achieve no appreciable reduction in viral transmission. Arguably of more interest are the indications that powerful forces within the academic world were at work to obstruct the dissemination of this inconvenient truth.
In regard to the potential benefits of mask-wearing, the findings of the review were emphatic: after considering 12 research trials (ten in the community and two among hospital workers) the main takeaway message was that face coverings made “little or no difference to influenza-like or COVID-19-like illness transmission”. When only studies where respiratory infections had been confirmed in a laboratory were included in the analysis, the conclusion was even more stark: “Wearing masks had no effect on… influenza or SARS-CoV-2 outcomes”. Furthermore, the type of mask used – the surgical variety or the higher-quality N95/P2 respirators – made no difference to the outcome.
It is plausible to assume that the conclusions of the Cochrane scholars did not make easy reading for the pro-mask establishment. The Covid era has been characterised by extraordinarily high levels of censorship of views that did not tally with the dominant public health narrative, and this silencing of alternative perspectives has often been evident within the academic and research spheres. A close inspection of the two most recent updates to the Cochrane review – their development and content – suggests that these malign forces of suppression may have been targeting this initiative in an effort to dilute the impact of its masks-are-ineffectual message. There are five observations consistent with this premise.
1. Scarcity of robust studies
It is intriguing that, three years after the start of the Covid event, there is a dearth of prospective randomised controlled trials (RCTs) – the type that provide the most robust kind of scientific evidence – to evaluate the efficacy of community masking as a means of reducing viral transmission. In the words of the Cochrane review authors, there was a “relative paucity” of such studies “given the importance of the question”. In a politicised environment, where Covid policy was often determined without recourse to empirical evidence, perhaps those in power did not want to fund research that would provide a definitive answer to the question of whether masks offered an effective viral barrier, particularly in light of the earlier discouraging results?
2. Unpublished research
In November 2020, the Danish mask study – the first RCT of mask efficacy specific to the SARS-CoV-2 virus – found that masks achieved no significant benefit for the wearer. Despite this ground-breaking conclusion, the research was initially rejected by at least three prestigious medical journals. This publication bias is also evident in the current Cochrane review where the authors, when discussing the range of RCTs included in the analysis, state that: “We identified four ongoing studies, of which one is finalised, but unreported, evaluating masks concurrent with the COVID‐19 pandemic” (my emphasis). Why would a finalised RCT, on such a pressing issue as mask effectiveness, not be published? The most likely answer, in this censorial environment, is that it came to the ‘wrong’ conclusion.
3. A disregard of the harms of masking
Very few of the studies included in the Cochrane review addressed the potential harms of wearing masks; harms were “rarely measured and poorly reported”. When one considers the wide range of credible negative consequences (physical, social and psychological) associated with mass masking in the community, this is a glaring omission. Once again, the most plausible reason for this inattention to harms in mask research in the last three years is political pressure – Government policy makers urgently sought evidence to support their premature decisions to impose mask mandates, to demonstrate their effectiveness as a viral barrier, and were disinclined to investigate the potential harms.
4. Publication delays
A blatant indication of top-down censorial influence on the ‘masks don’t work’ message is the way that publication of one of the Cochrane review updates was delayed. The previous 2020 version, incorporating updates up until January 2020, had passed peer review and was finalised by April of the same year. Extraordinarily, its publication was delayed until November 2020 due to “unexplained editorial decisions“. According to lead author, Dr. Tom Jefferson, this extra scrutiny was “a very unexpected event in Cochrane, especially during a period in which the topic of the review and the setting of policy was of global importance”.
It is unlikely to be coincidence that this window of delay corresponds to the period when the U.K. and other Governments, under intense pressure from pro-mask groups, U-turned and imposed mask mandates on their populations. In the midst of this policy flip-flop, it would have caused considerable political embarrassment to our public health leaders should the Cochrane group – the source of the most authoritative and comprehensive scientific evidence – have broadcast its conclusion that masks are ineffective as a viral barrier. In the words of Dr. Jefferson, by the time their report was published in November 2020, “the advisers had changed their minds about the evidence, and the policies had been set”.
The latest Cochrane review update includes studies up to October 2022. Its publication three months later suggest that this edition was not delayed, presumably because, at a time when most of society is unmasked, its conclusions are likely to evoke less discomfort for policy makers.
5. Editorial interference
An explicit example of the top-down interference with the Cochrane review process (referred to above) is an editorial that accompanied the 2020 edition. Including statements such as, “Waiting for strong evidence is a recipe for paralysis”, the content of this commentary appears totally at odds with the ethos of the Cochrane initiative. Indeed, this decisions-before-evidence assertion mirrors the proclamations of pro-mask zealot Professor Trish Greenhalgh, who has previously stated that the rigorous search for empirical evidence is the “enemy of good policy“.
In the words of Dr. Jefferson, the 2020 Cochrane editorial “seemed to undermine our work” and had the effect of “completely subverting the precautionary principle”. The lead author of the editorial was Dr. Soares-Weiser (Cochrane’s Chief Editor) who is “responsible for ensuring that the Cochrane Library meets its strategic goals of supporting health care decision-making by consistently publishing timely, high-priority, high-quality reviews”. Clearly, the 2020 Cochrane mask review failed her ‘timely’ criterion and her trivialisation of the value of empirical evidence is at odds with the ‘high-quality reviews’ aspiration.
Dr. Gary Sidley is a retired NHS consultant clinical psychologist and a co-founder of the Smile Free campaign that opposes mask mandates.