Cohort profile: the British Columbia COVID-19 Population Mixing Patterns Survey (BC-Mix)

Abstract

PurposeSeveral 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.ParticipantsThe 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 dateAs 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 plansMultiple 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.

Association between close interpersonal contact and vaccine hesitancy: Findings from a population-based survey in Canada

“…As of June 2022, more than 88,000 individuals had participated in the survey. Further details about the survey development, design and domains are described in detail elsewhere ( 20 – 22 ). We followed the checklist for Reporting Results of Internet E-Surveys (CHERRIES) ( 23 ).…”

“…Participant characteristics were summarized using weighted frequencies and percentages and are presented in Table 1 . Survey methodology and weighting technique have been described elsewhere ( 20 ). Characteristics of study participants were stratified by contact rate ( Table 2 ) and also by COVID-19 vaccine hesitancy ( Table 3 ).…”

“…All analyses incorporated survey sampling weights that were estimated based on age, sex, geography (region), and ethnicity distribution as described elsewhere ( 20 ). All tests were two-sided significant at the 0.05 level.…”

The Impact of Mask Mandates on Face Mask Use During the COVID-19 Pandemic: Longitudinal Survey Study

“…The BC COVID-19 Population Mixing Patterns (BC-Mix) survey is an ongoing web-based survey developed to assess population mixing patterns during the COVID-19 pandemic among BC residents [39]. The survey, launched on September 4, 2020, is composed of 94 questions across six key domains:…”

“…Anonymous links to the survey were circulated via advertisements placed on Google and social media platforms, namely Instagram, Facebook, WhatsApp, YouTube, and Twitter. Detailed descriptions of survey design, domains, and recruitment methods have been published elsewhere [39]. Participants completed a baseline survey (for first-time respondents), and those who consented were invited to complete shorter follow-up surveys every 2 to 4 weeks.…”