B.C.'s public health approach to COVID-19 appears to be working

Physical distancing is central to many governments’ public health strategies to slow the transmission of the COVID-19 pandemic. However, the parameters, implementation and enforcement of physical distancing vary greatly across jurisdictions. The B.C. government has been commendably clear, nuanced and pragmatic in issuing guidance to businesses about whether to shut down or continue operating with modified workplace practices that achieve physical distancing (see here). Its guidance to citizens has been similarly practical and effective, as the data below suggests.

Public health data

The most recent modelling from the B.C. Centre for Disease Control (BCCDC) was released on April 17. It suggests B.C.’s various public health measures are working, as evidenced by the slowdown in new confirmed case (Figure 1). B.C.’s cumulative COVID-19 case rate is tracking well below Spain, United States, Italy, Germany, United Kingdom, Norway, Hubei province and Canada (Figure 2). Overall, B.C.’s outbreak appears to be tracking close to Australia’s. Among the selected jurisdictions, only South Korea, Singapore and Hong Kong are showing fewer confirmed cases per million population since the start of the outbreak.

Figure 1: Public health measures and new confirmed COVID-19 cases in B.C.

Figure 2: B.C. is tracking well below other countries' outbreaks

Mobility data

Google data on Canadians’ mobility, released on March 29, appears to corroborate the BCCDC data. Using (opted-in) location-enabled data from users’ accounts, Google tracked people’s mobility (i.e. number of visits and length of stay) across six major types of locations:

• public transit – bus, train and subway stations;
• retail and recreation – restaurants, cafes, shopping centres, theme parks, museums, libraries and movie theatres;
• workplaces – places of work
• grocery and pharmacy – grocery markets, food warehouses, farmers’ markets, specialty food shops and pharmacies
• parks – national parks, public beaches, marinas, dog parks, plazas and public gardens; and
• residences – residential areas.

Figure 3a shows changes in user mobility by province. We rank the activities according to their likely potential for virus transmission. Users’ change in mobility (February 16 to March 29) is compared to a baseline (median mobility for January 3 to February 6) on the same day of the week.

B.C. appears to have achieved the “biggest bang for its buck” – that is, introducing or encouraging physical distancing measures that achieve the greatest reduction in virus transmission for the least economic and societal cost (see hereand herefor further discussion). As Figure 3a shows, B.C. has achieved significant reductions in human activity around transit, retail and recreation and workplaces. By contrast, some other provinces, especially Quebec, appear to have sought blanket reductions around all types of activity, including parks.

Figure 3a: B.C. has focused on reducing high-transmission activities - transit, retail, workplaces

Figure 3b sorts the mobility data by type of activity. B.C., Ontario, Quebec and Canada are highlighted. B.C. has achieved greater reductions in mobility around workplaces than Ontario, Quebec or Canada. Compared to those jurisdictions, it has achieved only slightly smaller reductions in mobility around transit, retail and recreation, and grocery and pharmacy locations.

Figure 3b: B.C. has focused on curtailing high-transmission activities - transit, retail, workplaces

Conclusion

Overall, BCCDC data on cumulative case rates and Google data on user mobility reductions suggest B.C.’s public health strategy is both appropriate and effective. The B.C. government appears to have adopted a commendably clear, targeted and pragmatic approach to reducing virus transmission, while also trying to minimize the economic and societal costs.