22 April 2022

Study to assess the incidence of COVID-19 in Quebec - Updated with data from the week of April 14 to 19, 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 fourteenth week of collection, which took place from April 14 to 19, 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.

→ Fourteenth week of collection (April 14 to 19, 2022)

Highlights:

Slight decrease in case incidence relative to the previous week for all estimators (10% decrease for direct method estimates and 2% to 5% for RPA method estimates - not statistically significant decreases) Between 28,000 and 53,000 cases per day, Depending on the estimation method used (similar to collection week 1 or 2 - i.e., January 2022) Decrease in case incidence (not statistically significant) for all age groups (except for 50-59 year olds who experienced a 6.5% increase after stagnation last week). Particularly high decline in 18-29 year olds (not significant). Decrease in most regional groupings, but this seems to mask region-specific variations. Increase in Western regions after a plateau last week. 7.4% of Quebecers were in isolation during the week ending April 14-19 - similar to the previous week.

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).