Dr. Matt Strauss used one of his final public appearances as acting medical officer of health for Haldimand-Norfolk to highlight a new Cochrane review that calls into question the effectiveness of masking to prevent the community spread of infectious diseases like COVID-19.
Cochrane is a UK-based organization that performs meta-analysis of medical research findings to answer specific research questions. At this week’s board of health meeting, Strauss called its work “the gold standard … for the last three decades.”
However, a team of scientific experts took issue with the review’s methodology in a recent article published online in The Conversation.
The review, published Jan. 30, analyzed the results of 78 randomized controlled trials, or RCTs, and “concluded, with low to moderate certainty, that masking probably has little to no effect in terms of preventing community transmission,” Strauss said.
A summary of the study online indicated the authors are “uncertain whether wearing masks or N95/P2 respirators helps to slow the spread of respiratory viruses based on the studies we assessed.”
All but six RCTs — which Strauss called “the highest level of medical experiment” — were conducted before the COVID-19 pandemic. The review says the evidence it summarizes on the use of masks is “largely based on studies conducted during traditional peak respiratory virus infection seasons up until 2016.”
The Cochrane analysis found masking in the community “may make little to no difference” to how many people become sick with respiratory illnesses, while handwashing “is likely to modestly reduce the burden of respiratory illness.”
The review’s authors acknowledged the difficulty in reaching firm conclusions.
“Relatively low numbers of people followed the guidance about wearing masks or about hand hygiene, which may have affected the results of the studies,” the report read.
At the health board meeting, Coun. Kim Huffman pointed out that the authors of the Cochrane review were “uncertain whether masks — N95 or otherwise — slow the spread of respiratory viruses.”
“So I don’t think they’re coming right out and saying that masks don’t work,” Huffman said.
In January, Strauss announced his resignation as acting medical officer of health as of April 1 after being in the role for less than two years.
During his time as top doctor, Strauss became known outside Haldimand-Norfolk for his objection to the use of measures such as lockdowns, vaccine passports and vaccine mandates to curb the spread of COVID-19, saying such approaches missed the mark.
There has been pushback on the Cochrane review in the public health sphere.
Dr. David Fisman, an epidemiologist at the University of Toronto’s Dalla Lana School of Public Health, co-authored a refutation of the review published in The Conversation.
Fisman, a former member of the province’s now-disbanded science table, and his co-authors took issue with the methodology of the Cochrane review, saying its authors erred by lumping together studies where masks were worn all the time with studies where they were only worn part of the time.
“If apples work but oranges don’t, combining all studies in a single average figure may lead to the conclusion that apples do not work,” they said.
“If in a study of masking, most people don’t actually wear them, you can’t conclude that masks don’t work when the study shows no difference between the groups. You can only conclude that the mask advice didn’t work.”
Fisman’s team criticized Cochrane for exclusively studying RCTs when, they argued, a mix of study types would have better assessed the research questions posed. Performing meta-analysis only makes sense if all studies are “addressing the same research question in the same way,” the authors wrote.
They pointed to other studies done during the pandemic that showed wearing masks of any kind did reduce transmission by 50 to 80 per cent, with N95 respirators offering the most protection.
“There is strong and consistent evidence for the effectiveness of masks and (even more so) respirators in protecting against respiratory infections,” the authors wrote.
Strauss said having trained medical staff use masks correctly in clinical settings remains effective, but the evidence suggests more general mask use does little to stop transmission.
“I’m very careful not to say that masks don’t work,” Strauss told the health board.
“At a community level, there is not good evidence to say that they work, and as a medical practitioner it’s important to me that when I make recommendations, they’re based on the best evidence.”
count. Linda Vandendriessche noted the provincial health ministry still promotes the benefits of masking.
“I think the conclusion of this Cochrane collaboration that masks probably don’t work means that a lot of political bodies got erroneous (scientific) advice,” Strauss replied.
“Frankly, there’s a lot of egg to go around on a lot of faces in public health.”
JP Antonacci is a Local Journalism Initiative reporter based at the Hamilton Spectator. The program is funded by the Government of Canada.