A man wears a face mask as he looks at a COVID-19 information sign in Montreal, Sunday, Sept. 20, 2020, as the COVID-19 pandemic continues in Canada and around the world. THE CANADIAN PRESS/Graham Hughes

Preliminary B.C. study results suggest mask mandates can lower COVID-19 spread by 25%

Study has not yet been printed or peer reviewed

Preliminary results from a study conducted by Simon Fraser University researches suggests that a mask mandate can lower the transmission of COVID-19 by 25 per cent each week.

Study results, released prior to peer review on Wednesday (Oct. 7), show that mandating masks indoors nationwide in early July could have reduced new weekly cases by 25 to 40 per cent in mid-August. That would translate approximately to 700 to 1,1000 fewer cases each week.

Researchers from SFU’s economics department focused on mask mandates brought in across Ontario’s 34 Public Health Units over the course of two months this year. Results from comparing units that went to mask mandates early, versus later, showed that earlier adoption was association with an average weekly reduction of 25 to 31 per cent, in July and August. There has been no mask mandate province-wide in B.C., although many government buildings, grocery stores and other businesses have brought in mask rules of their own.

ALSO READ: B.C. records 102 new COVID-19 cases, 2 deaths

The results of SFU’s study differed from an earlier one about mask mandates in the U.S., which found a nine to 10 per cent reduction in new cases.

“One possible explanation is that Ontario’s mask policy is more comprehensive: we evaluate the effect of universal indoor mask-wearing for the public rather than the effect of mask wearing for employees only in [the U.S. study]. Differences in the compliance rate may also contribute to this difference,” researchers noted.

An analysis of mask mandates across the country found a reduction in new cases of up to 46 per cent in the first weeks after adoption. Researchers also saw that mask mandates increased self-reported use by 30 per cent.

“Jointly, these results suggest that mandating indoor mask wear in public places is a powerful policy measure to slow the spread of COVID-19, with little associated economic disruption in the short term,” the study concluded.

Researchers also looked at COVID-19 restrictions and their effect on new cases. They found that the most stringent restrictions were associated with a decrease of 48 to 57 per cent in weekly cases.

Study authors noted that while the results are significant, “their sample period does not allow them to definitively say whether the effect of mask mandates persists or weakens beyond the first few weeks after implementation.”

ALSO READ: Anti-mask protest at Kelowna schools ‘disappointing,’ says superintendent


@katslepian

katya.slepian@bpdigital.ca

Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

The last forum before the election on Saturday focused on health care.
Boundary-Similkameen candidates talk health care over digital forum

The Support Our Health Care Society hosted the forum

The Regional District of Okanagan Similkameen is planning to implement transit service in the West Bench area in September, 2021. (Black Press file photo)
Regional district to bring transit service to West Bench in 2021

Residents of area near Penticton will be consulted before plans are finalized

COVID-19. (Image courtesy CDC)
Interior Health reports 18 COVID-19 cases, highest daily count since July

The total of COVID-19 cases in the region is now at 662

Carmi Elementary students voted through CIVIX Students Vote. (Lesley Evans photo)
Penticton students have their say in B.C. election

Twelve schools, including Carmi Elementary participated in Student Vote

A Kelowna clinic decided to immunize their patients in a drive-thru flu clinic earlier this month. (Twila Amato - Black Press Media)
Interior Health anticipates increase in flu vaccinations this season

Some 300,000 doses of flu vaccine ready for distribution across Southern Interior

B.C. provincial health officer Dr. Bonnie Henry gives a daily briefing on COVID-19 cases at an almost empty B.C. Legislature press theatre in Victoria, B.C., on March 25, 2020. (Don Craig/B.C. government)
B.C. sees 223 new COVID-19 cases, now 2,009 active

Two new care home outbreaks in Surrey, Burnaby

Thanks to efforts by a Kelowna shelter and Elections BC, anyone who wishes to can vote in the 2020 BC Provincial Election, even if they don’t have a fixed address. (THE CANADIAN PRESS/Darryl Dyck)
Kelowna group ensures people experiencing homelessness can vote

Shelter supervisor says voting ‘a fundamental right’ even for those without a fixed address

(Big White Ski Resort photo)
Big White receives 21 cm of snow in 24 hours

Resort’s snow base 41 cm deep, one month until opening day

The deer were allegedly shot within Princeton town limits, late at night. Black Press File Photo.
Armed man, in full camouflage, allegedly shoots deer in downtown Princeton

‘The list of charges goes on and on,’ said RCMP Sgt. Rob Hughes

100 Mile Conservation officer Joel Kline gingerly holds an injured but very much alive bald eagle after extracting him from a motorist’s minivan. (Photo submitted)
B.C. driver thought he retrieved a dead bald eagle – until it came to life in his backseat

The driver believed the bird to be dead and not unconscious as it turned out to be

Members of Summerland council and municipal staff were present on Oct. 22 to officially open the expanded Summerland landfill facility. From left are manager of environmental services Candace Pilling, Coun. Erin Carlson, Coun. Marty Van Alphen, acting mayor Doug Holmes, Coun. Richard Barkwill and Coun. Erin Trainer. (John Arendt - Summerland Review)
Changes made to entrance of Summerland landfill

Upgrades came at cost of $500,000

Chastity Davis-Alphonse took the time to vote on Oct. 21. B.C’s general Election Day is Saturday, Oct. 24. (Chastity Davis-Alphonse Facebook photo)
B.C. reconciliation advocate encourages Indigenous women to vote in provincial election

Through the power of voice and education Chastity Davis-Alphonse is hopeful for change

White Rock RCMP Staff Sgt. Kale Pauls has released a report on mental health and policing in the city. (File photos)
White Rock’s top cop wants to bill local health authority for lengthy mental-health calls

‘Suggestion’ included in nine-page review calling for ‘robust’ support for healthcare-led response

Most Read