18 March 2022

Study to assess the incidence of COVID-19 in Quebec - Updated with data from the week of March 10 to 15, 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 ninth week of collection, which took place from March 10 to 15, 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.

→ ninth week of collection (March 10 to 15, 2022)

Highlights:

Our estimates based on the indirect sampling method show a non-statistically significant decrease in the number of new cases for this collection week compared to the previous week (8.7% to 11.4% decrease depending on the estimator). The direct sampling estimates show similar results, with a decrease in case incidence (on the order of 18.9%) when self-tests are included, or a 12.4% decrease for the estimate excluding self-tests. All of these differences, however, are not statistically significant. In comparison, case count data based on PCR tests collected by the INSPQ show a decrease of approximately 4.1% between week 8 and week 9 of collection.

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) and Ingrid Peignier (CIRANO)