19 March 2022

Study to assess the incidence of COVID-19 in Quebec - Updated with data from the week of March 17 to 22, 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 tenth week of collection, which took place from March 17 to 22, 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.

 

Tenth week of collection (March 17 to 22, 2022)

Highlights: 
All four estimators were in agreement and showed a more or less slight increase (statistically significant (p<0.1) for the direct positives and not statistically significant for the others) in the incidence of cases relative to the previous week.
The data show a slight increase in persons in isolation (1st increase since the beginning of the study in January) during the week ending March 22.
These results suggest that we are no longer on a plateau but that an increase in the incidence of cases appears to be occurring. This upward trend will need to be confirmed next week.
Notwithstanding the direction of the trend compared to the previous week, the number of cases varies from 13,500 to 19,500 cases per day, depending on the estimation method used (this figure even rises to slightly more than 24,000 cases per day with the direct sampling method including self-diagnoses). 

 

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).