A NOVEL new study suggests that the behaviour public officials are now mandating or recommending unequivocally to slow the spread of surging COVID-19–wearing a face covering–should come with a caveat. If not accompanied by proper public education, the practice could lead to more infections.
The finding is part of a unique study, just published in JMIR Public Health and Surveillance, that was conducted by a team of health economists and public health faculty at the University of Vermont’s Larner College of Medicine in partnership with public health officials for the state of Vermont.
The study combines survey data gathered from adults living in northwestern Vermont with test results that showed whether a subset of them had contracted COVID-19, a dual research approach that few COVID studies have employed. By correlating the two data sets, researchers were able to determine what behaviours and circumstances increased respondents’ risk of becoming sick.
The key risk factor driving transmission of the disease, the study found, was the number of daily contacts participants had with other adults and seniors.
That had relevance for two other findings.
Those who wore masks had more of these daily contacts compared with those who didn’t, and a higher proportion contracted the virus as a result.
Basic human psychology could be at work, said Eline van den Broek-Altenburg, an assistant professor and vice-chair for Population Health Science in the Department of Radiology at the Larner College of Medicine and the study’s principal investigator.
“When you wear a mask, you may have a deceptive sense of being protected and have more interactions with other people,” she said.
The public health implications are clear. “Messaging that people need to wear a mask is essential, but insufficient,” she said. “It should go hand in hand with an education that masks don’t give you a free pass to see as many people as you want. You still need to strictly limit your contacts.”
Public education messaging should make clear how to wear a mask safely to limit infection, van den Broek-Altenburg added.
The study also found that participants’ living environment determined how many contacts they had and affected their probability of becoming infected. A higher proportion of those living in apartments was infected with the virus compared with those who lived in single-family homes.
“If you live in an apartment, you’re going to see more people on a daily basis than if you live in a single-family home, so you need to be as vigilant about social distancing,” van den Broek-Altenburg said.
The study controlled for the profession to prevent essential workers, who by definition have more contacts and are usually required to wear masks, from skewing the results.
“It’s generally known that essential workers are at higher risk, and our study bore that out,” van den Broek-Altenburg said. “We wanted to see what else predicted that people were going to get sick,” she said.