13 May 2022

Study to assess the incidence of COVID-19 in Quebec - Updated with data from the week of May 5 to 10, 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 seventeenth week of collection, which took place May 5 to 10, 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.

→ Seventeenth week of collection (May 3 to 10, 2022)

Highlights:

Non-significant decline in case incidence from the previous week for all estimators (ranging from 9% to 24% depending on the estimator used). Between 17,000 and 34,000 cases per day, depending on the estimation method used. No clear trend in incidence by age category:
- Large and significant decrease in case incidence for 18-29 year olds (decrease in incidence by half, from 8.76% to 4.8%)
- Significant increase for 50-59 year olds and non-significant increase for 30-39 and over 70 year olds
- Non-significant decrease for other age groups
Decrease in the incidence of cases in the majority of Quebec's regional groupings. These trends by regional groupings mask variations specific to certain regions (e.g.: significant increase in Abitibi and Centre du Québec and significant decrease in Laurentides and Capitale Nationale).

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).