Further studies will not solve the mask debate

EEarlier this summer, Experts published a 38,000-word, multidisciplinary review of the evidence on mask-wearing against infectious diseases. They concluded that masks work, and better masks work better. Given the depth of the paper, the authors seemed to want to end a long-standing scientific debate about the effectiveness of masks.

Of course, that won’t happen – because the controversy over mask-wearing isn’t really a debate about science and evidence. It’s about values ​​and culture. Where should policy go if there is no complete or optimal evidence? How can we balance competing interests and trade-offs, regardless of the science?

The debate over mask-wearing shows that human behavior and public health recommendations ultimately boil down to implicit risk management decisions: the political and societal process of decision-making that considers risk among other priorities. Risk assessment—that is, following the data—can only serve as a basis for risk management. It cannot tell us how to weigh the inevitable trade-offs.

Mask mandates and seemingly scientific debates about lockdowns or other public health precautions like controversial mammography guidelines will not be resolved until key stakeholders communicate more transparently about how scientific analysis aligns with culture, values, and priorities. With the increasing threat of outbreaks of the MPOX and H5N1 influenza viruses, there is an urgent need for better communication about how decision-makers manage risk and weigh potential benefits and harms.

The spark in the debate over masks began with the first arguments about lockdowns at the beginning of the Covid-19 pandemic. One camp of experts claimed that measures such as widespread and complete pandemic lockdowns should be lifted because there was no solid evidence from randomized controlled trials (RCTs) of their effectiveness.

Others disagreed. Trisha Greenhalgh, a prominent member of the evidence-based medicine movement, argued in a 2020 article published in PLOS Medicine that “the costs of inaction are reflected in the grim death figures announced daily, implementing new policy interventions in the absence of randomized trial evidence has become both a scientific and moral imperative.” Not surprisingly, Greenhalgh was the lead author of the recent 38,000-word review on mask wearing.

The positions of the two camps were clear. One advocated randomized controlled trials (RCTs) before adopting measures, while the other argued that there was already enough evidence to take such precautions. As lockdowns were eased, debates focused more on masks and mask mandates, but the divide remained.

It seems to be a common divide in debates that, on the surface, appear scientific. As I wrote in a recent essay for the Sensible Medicine newsletter, similar camps emerge when examining breast cancer screening guidelines. In her book Mammography Wars, Asia Friedman, a sociologist at the University of Delaware, described the two camps as skeptics and interventionists. Skeptics advocate screening starting at age 50, while interventionists advocate earlier screening. In fact, there is evidence to support both positions, which is partly why the U.S. Preventive Services Task Force guidelines fluctuate on the issue.

Friedman’s article suggests that the question “at what age should breast cancer screening begin?” is not really about the science of risk assessment, but about risk management. Statistical estimates of false positives and false negatives, as well as lives saved, when screening at age 40 or 50 are well documented. So the risk management question is: How should individuals and society manage costs while improving health outcomes?

Interventionists are primarily concerned about missed cancers and false negatives—they prioritize patient preferences for earlier screening and focus on not missing anything—and pay less attention to concerns about overdiagnosis and overtreatment. Skeptics, on the other hand, take a population health perspective that aims to minimize overdiagnosis and overtreatment, maximize the population health benefits of screening, and use the fewest resources possible. This approach recognizes an inevitable trade-off: reducing overall costs may result in rare but tragic missed cases.

Who is right? That depends on your perspective. Patients may prefer an interventionist approach to avoid worry. European health policymakers or American insurance companies are likely to see the costs of an interventionist approach as not justified by the perceived benefits. But the key point is that there is no right or wrong, just risk management decisions that are about balancing trade-offs. Since any risk assessment is fraught with assumptions, uncertainties and unknowns, there are countless ways to manage risk and associated trade-offs.

In a democracy, we supposedly elect representatives who will enforce our shared values ​​in risk management decisions. When they don’t, we try to vote them out, because projecting one person’s values, identity and preferences onto other people without the opportunity to have a say leads to a response similar to the pandemic we’re seeing against mask mandates and lockdowns. Worse, when those in positions of power do this, it could well be called oppression or cultural imperialism. As one Norwegian academic put it in a 1998 journal article, “Epidemiologists and the health movement in general have a mandate to fight disease and premature death; they have no explicit mandate to change culture.”

This suggests that the debate around mask wearing will continue, despite the review by Greenhalgh and his colleagues, or the next one. Interventionists will continue to argue for a precautionary approach, favoring potentially life-saving measures even when the side effects of such interventions are uncertain. Until enough randomized trials are conducted, sceptics will continue to argue that more and stronger evidence is needed before making policy decisions with potentially serious consequences. When these debates are played out in public, most of us are left confused and bewildered.

This lack of clarity risks repeating the mistakes of the pandemic as MPOX and H5N1 outbreaks pile up. An editorial in The Lancet Infectious Diseases in July noted that a search of the PubMed database for “COVID-19 lessons” returned nearly 5,000 results and asked, “Have we learned anything?” “Not really,” the editorial concluded, decrying the lack of urgency and scale in tackling H5N1 in the United States. ^{and Mpox in Africa.}

Instead, the editorial argued, the “cynical viewpoint” should have focused more on the policy lessons emerging from the pandemic’s damaging economic impact and resulting voter behavior. Seemingly resigned, the editorial’s authors implicitly acknowledged that their area of ​​expertise was risk assessment, not risk management, saying, “This is not our jurisdiction as a medical journal.”

Ostensibly scientific debates over mask mandates, mammography screening, and now approaches to combating H5N1 and Mpox outbreaks seem to perpetuate the failures of the pandemic. Scientists, policymakers, and the media must be open with the public about how they integrate scientific analysis with differing social, economic, and health priorities into their recommendations and policy decisions. A clear outline of the values ​​that matter can help us move beyond bitter debates about absolutes—“mask!” or “no mask!”—and into more productive discussions about competing values, priorities, and trade-offs.

David Scales, M.Phil., MD, Ph.D., is a physician and sociologist at Weill Cornell Medicine. He researches controversial diseases and medical misinformation and designs and tests community-based interventions to address information bias online.