More studies won’t solve the masking debate

This commentary was originally published by Undark.

Earlier this summer, experts published a 38,000-word, multidisciplinary review of the evidence on masking against infectious disease. Masks work, they concluded, and better masks work better. Given the paper’s depth, the authors appeared to seek to end a long-running scientific debate on the effectiveness of masking.

Of course, that won’t happen — because the controversy over masking is not really one of science and evidence. It is about values and culture. Lacking complete or optimal evidence, how should policy lean? How do we balance competing interests and trade-offs, regardless of the science?

The masking debate shows that human behavior and public health recommendations boil down to implicit decisions about risk management: the political and social process of making decisions that incorporate risk, amid other priorities. Risk assessment — that is, following the data — can only inform risk management. It cannot tell us how to weigh the inevitable trade-offs.

Masking and seemingly scientific debates about lockdowns or other public health precautions such as controversial mammography guidelines won’t be resolved until key stakeholders communicate more transparently about how scientific analysis is merged with culture, values, and priorities. As the threat of mpox and H5N1 influenza outbreaks grows, there is an urgent need for better communication about how decision-makers manage risks and weigh potential pros and cons.

The spark in the masking debate began with the initial arguments over lockdowns at the start of the Covid-19 pandemic. One camp of experts asserted that measures like widespread and complete pandemic lockdowns should be lifted in the absence of robust evidence from randomized controlled trials, or RCTs, showing their efficacy.

Others disagreed. Trisha Greenhalgh, a prominent member of the evidence-based medicine movement, argued in a 2020 article published in PLOS Medicine that “where the cost of inaction is counted in the grim mortality figures announced daily, implementing new policy interventions in the absence of randomized trial evidence has become both a scientific and moral imperative.” Unsurprisingly, Greenhalgh was the first author on the recent 38,000-word review of masking.

The two camps’ positions were clear. One advocated for RCTs before enacting policy, while the other argued there was already sufficient evidence to take such precautions. As lockdowns eased, debates focused more on masks and mask mandates, but the divide remained entrenched.

It seems to be a common divide in debates that appear scientific at the surface. As I wrote in a recent essay for the newsletter Sensible Medicine, 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 argue for screening beginning at 50, while interventionists advocate for screening earlier. In fact, there is evidence to support either position, which is partly why U.S. Preventive Services Task Force guidelines have vacillated on the issue.

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

Interventionists are primarily concerned with missed cancers and false negatives — prioritizing patient preferences for earlier screening and focusing on not missing anything — and pay less attention to worries about overdiagnosis and overtreatment. Skeptics, on the other hand, take a population-health perspective, which seeks to minimize overdiagnosis and overtreatment, maximize the population health benefit from screening, and expend the fewest resources. 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 for peace of mind. European public health policy makers or American insurance companies will likely see the costs of an interventionist approach as not justifying the perceived benefits. But the key point is that there is no right or wrong, only risk management decisions trying to balance trade-offs. Since every risk assessment is loaded with assumptions, uncertainties, and unknowns, there are myriad paths for managing risks and associated trade-offs.

In a democracy, we ostensibly elect representatives to enact our shared values in risk management decisions. If they don’t, we try to vote them out, because projecting one individual’s values, identity, and preferences onto other people without an opportunity for input invites the kind of pandemic backlash seen against masking and lockdowns. Worse, when those in positions of power do it, one could reasonably call it oppression or cultural imperialism. As one Norwegian scholar put it in a 1998 journal article: “Epidemiologists and the health care movement in general have a mandate to fight disease and premature death; they have no explicit mandate to change culture.”

This suggests the masking debate will continue, despite Greenhalgh and colleagues’ review or the next. Interventionists will continue to argue for a precautionary approach, prioritizing potentially life-saving measures even when the side effects of such interventions are uncertain. Until sufficient randomized studies are done, skeptics will continue arguing that more and stronger evidence is needed before making policy decisions with potentially severe consequences. If these debates play out publicly, most of us are left bewildered and confused.

That lack of clarity risks repeating the mistakes of the pandemic, as mpox and H5N1 outbreaks proliferate. Noting that nearly 5,000 results come back from a search of the PubMed database for “COVID-19 lessons learned,” a July editorial in The Lancet Infectious Diseases asked, “Have we learned anything?” “Not really,” the editorial concluded, denouncing the lack of urgency and scale in addressing H5N1 in the United States and mpox in Africa.

Instead, according to what the editorial characterized as the “cynical view,” there should have been more focus on political lessons influenced by the pandemic’s damaging economic impact and ensuing voter behavior. Seemingly resigned, the editorial’s writers implicitly acknowledged that their lane is risk assessment and not risk management, saying “this is not our purview as a medical journal.”

Ostensibly scientific debates about masking, mammography screening, and now, approaches to managing H5N1 and mpox outbreaks seem set to perpetuate the mistakes of the pandemic. Scientists, policymakers, and the media need to be explicit with the public on how they are integrating scientific analysis with different social, economic, and health priorities in their recommendations and policy decisions. Being explicit about what values are being prioritized may help us move past bitter debates about absolutes — “Mask!” or “Don’t mask!” — to more productive discussions about competing values, priorities, and trade-offs.

Dr. David Scales is a physician and sociologist at Weill Cornell Medicine. He studies contested illnesses and medical misinformation, designing and testing community-based interventions to address information distortion in online settings.