15 April 2022

Study to assess the incidence of COVID-19 in Quebec - Updated with data from the week of April 7 to 12, 2022

CIRANO has published an update of its exploratory study to estimate the incidence of COVID-19 cases in Quebec. This update integrates the data from the thirteenth week of collection, which took place from April 7 to 12, 2022, with a sample of 3000 respondents representative of the Quebec population and compares them to other collection weeks.

It should be noted that this study is spread over several consecutive weeks in order to monitor the evolution of the situation. The study uses both a direct sampling strategy and an indirect sampling estimation based on the network scale-up (NSS) method. Details of the methods are available in the CIRANO 2022s-03 working paper.

→ Thirteenth week of collection (April 7 to 12, 2022)

Highlights:

Increase in incidence of cases relative to the previous week (statistically significant (p<0.01) for all estimators. 52% increase in cases from the previous week for the direct method. Between 30,000 and 60,000 cases per day, depending on the estimation method used.

Increase in case incidence for all age groups (significant in 40-49 year olds). Approximately one out of every 10 18-29 year olds person became infected with COVID during the week. Increase in all regional groupings, but appears to mask region-specific variations.

7.3% of Quebecers were in isolation during the week ending April 7-12 - a statistically significant increase from the previous week (5.4%).

This study is conducted by a team of researchers composed of David Boisclair (HEC Montréal), Roxane Borgès Da Silva (Université de Montréal and CIRANO), Vincent Boucher (Université Laval) Nathalie de Marcellis-Warin (Polytechnique Montréal and CIRANO), Pierre-Carl Michaud (HEC and CIRANO), Ingrid Peignier (CIRANO) and Alexandre Pud'Homme (Université de Montréal).