ABSTRACT
BACKGROUND: Face mask usage has been associated with declines in COVID-19 incidence rates worldwide. A handful of studies have examined the factors associated with face mask usage in North America during the COVID-19 pandemic, however much less is known about the patterns of face mask usage and the impact of mask mandates during this time. This information could have important policy implications, now, and in the event of future pandemics. OBJECTIVE: To address existing knowledge gaps, we assessed face mask usage patterns among British Columbia COVID-19 Population Mixing Patterns (BC-Mix) survey respondents, and evaluated the impact of the provincial mask mandate on these usage patterns. METHODS: Between September 2020 and July 2022, adult British Columbia residents completed the online BC-Mix survey, answering questions on the circumstances surrounding face mask usage or lack thereof, movement patterns, and COVID-19-related beliefs. Trends in face mask usage over time were assessed, and associated factors were evaluated using multivariable logistic regression. A stratified analysis was done to examine effect modification by the provincial mask mandate. RESULTS: Of the 44,301 respondents, 81.9% reported wearing face masks during the 23-month period. In-store and public transit mask mandates supported monthly face mask usage rates of approximately 80%, further bolstered up to 92% with the introduction of the provincial mask mandate. Face mask users mostly visited retail locations (51.8%) and travelled alone by car (49.6%), while non-users mostly traveled by car with others (35.2%) to their destinations; most commonly parks (45.7%). Non-users of face masks were much more likely to be male than female, especially in retail locations, and restaurants, bars and cafés. In a multivariable logistic regression model adjusted for possible confounders, factors associated with face mask usage included age, ethnicity, health region, mode of travel, destination, and time period. The odds of face mask usage were 3.68 times greater when the provincial mask mandate was in effect than when it was not (adjusted odds ratio [OR]: 3.68, 95% confidence interval [CI] 3.33-4.05). The impact of the mask mandate was greatest in restaurants, bars, or cafés (aOR: 7.35, 95% CI 4.23-12.78 [mandate] vs. 2.81, 95% CI 1.50-5.26 [no mandate]), and in retail locations (aOR: 19.94, 95% CI 14.86-26.77 [mandate] vs. 7.71, 5.68-10.46 [no mandate]). CONCLUSIONS: Study findings provide added insight into the dynamics of face mask usage during the COVID-19 pandemic. Mask mandates supported increased and sustained high face mask usage rates during the first two years of the pandemic, having the greatest impact in the indoor public locations with limited opportunity for physical distancing targeted by these mandates. These findings highlight the utility of mask mandates in supporting high face mask usage rates during the COVID-19 pandemic.
ABSTRACT
PURPOSE: Several non-pharmaceutical interventions, such as physical distancing, handwashing, self-isolation, and school and business closures, were implemented in British Columbia (BC) following the first laboratory-confirmed case of COVID-19 on 26 January 2020, to minimise in-person contacts that could spread infections. The BC COVID-19 Population Mixing Patterns Survey (BC-Mix) was established as a surveillance system to measure behaviour and contact patterns in BC over time to inform the timing of the easing/re-imposition of control measures. In this paper, we describe the BC-Mix survey design and the demographic characteristics of respondents. PARTICIPANTS: The ongoing repeated online survey was launched in September 2020. Participants are mainly recruited through social media platforms (including Instagram, Facebook, YouTube, WhatsApp). A follow-up survey is sent to participants 2-4 weeks after completing the baseline survey. Survey responses are weighted to BC's population by age, sex, geography and ethnicity to obtain generalisable estimates. Additional indices such as the Material and Social Deprivation Index, residential instability, economic dependency, and others are generated using census and location data. FINDINGS TO DATE: As of 26 July 2021, over 61 000 baseline survey responses were received of which 41 375 were eligible for analysis. Of the eligible participants, about 60% consented to follow-up and about 27% provided their personal health numbers for linkage with healthcare databases. Approximately 83.5% of respondents were female, 58.7% were 55 years or older, 87.5% identified as white and 45.9% had at least a university degree. After weighting, approximately 50% were female, 39% were 55 years or older, 65% identified as white and 50% had at least a university degree. FUTURE PLANS: Multiple papers describing contact patterns, physical distancing measures, regular handwashing and facemask wearing, modelling looking at impact of physical distancing measures and vaccine acceptance, hesitancy and uptake are either in progress or have been published.