04 March 2022

Study to assess the incidence of COVID-19 in Quebec - Updated with data from the week of February 24 to March 1st, 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 seventh week of collection, which took place from February 24 to March 1st, 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.

 

→ Update 7th week of collection (February 24 to March 1st, 2022)

Highlights: 
The data collected in week 7 seem to confirm that the incidence of cases continues to decline slightly. Our estimators based on the indirect sampling method show a marginally statistically insignificant decrease. The very slight increase based on the direct sampling estimate is not significant. This seventh week of collection reinforces the fact that the network scale-up (NSS) method better tracks the long-term trend and that the NSS estimators are much more robust than the direct sampling strategy. In addition, the proportion of Quebec adults in isolation due to COVID-19, which had been steadily declining in all collection weeks from week 1 to week 4 (from 9% to 5.5%) and had stabilized at around 5.5% of the adult population since then, declined again to 4.1% last week and to 3.3% this week (statistically significant decline), thus confirming the downward trend in another way. The data for week 8 will provide longer-term confirmation of this downward trend.

 

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)