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

Area of Science:

• Public Health
• Epidemiology
• Social Science

Background:

• COVID-19 pandemic necessitated non-pharmaceutical interventions (NPIs) in British Columbia (BC).
• NPIs like physical distancing and handwashing were implemented to minimize infection spread.
• Effective public health policy requires understanding population behavior and contact patterns.

Purpose of the Study:

• To describe the design of the BC COVID-19 Population Mixing Patterns Survey (BC-Mix).
• To characterize the demographic profile of survey respondents.
• To establish a surveillance system for informing COVID-19 control measure adjustments.

Main Methods:

• An ongoing, repeated online survey initiated in September 2020.
• Participant recruitment primarily through social media platforms.
• Responses weighted by BC population demographics (age, sex, geography, ethnicity) for generalizability.
• Integration of census and location data for additional socio-economic indices.

Main Results:

• Over 41,000 eligible baseline responses collected by July 2021.
• Weighted demographics: ~50% female, ~39% aged 55+, ~65% identified as white, ~50% with university degrees.
• High consent rates for follow-up surveys and linkage to healthcare data.

Conclusions:

• The BC-Mix survey provides valuable data on population behavior during the COVID-19 pandemic.
• Findings support evidence-based adjustments to public health interventions.
• Future publications will detail contact patterns, intervention impacts, and vaccine acceptance.