How impactful was the Canadian COVID Alert App?

Our McGill research team has just issued a report on the effectiveness of the Canadian COVID Alert App. To conduct this assessment, we were provided access to data reported for Canada’s COVID Alert app installations and collected from the COVID Alert server. All of these data arrived as aggregate statistics broken down by province and device type; no personally identifiable information was involved in any aspect of this study.
Key Findings
  • In provinces with higher adoption of COVID Alert, the app had a significant impact on reported cases and deaths. In Newfoundland and Labrador, for example, in which just over 22% of residents installed the app, the estimated numbers of cases and deaths averted was between 39-68% of confirmed cases and deaths.
  • Nationally the COVID Alert app had limited impact because it was not widely used in the most populated provinces. In these provinces, the estimated numbers of cases and deaths averted by app usage was no more than 1-3% of confirmed cases and deaths.
  • In an international comparison to other exposure notifications apps, the COVID Alert app had a very low adoption rate compared to countries such as UK, Italy, NZ, France. However, of the 40+ exposure notification apps deployed internationally, very few reported adoption and efficacy numbers and those that did provide reports did so over different calendar periods, making a fair comparison of impact across all apps impossible.
  • To have impact, the app must be adopted - which involves a number of activities including users downloading and regularly consulting the app as well as health systems providing low friction ways for users to report a positive diagnosis through the app.
  • More actionable data should be collected while still protecting user privacy to better understand and improve app efficacy.
  • Both surveys and in-app usage information are essential and complementary sources of data for accurate assessments of app impact. These two kinds of data collection efforts should be designed together.
  • In the future, to better understand the impact of the app and how that impact can be improved, data collection needs to be designed with these kinds of analysis goals in mind.