This is a summary, written by members of the CITF Secretariat, of:

Archambault PM, Rosychuk RJ, Audet M, Bola R, Vatanpour S, Brooks SC, Daoust R, Clark G, Grant L, Vaillancourt S, Welsford M, Morrison LJ, Hohl CM; Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN) investigators; Network of Canadian Emergency Researchers; Canadian Critical Care Trials Group. Accuracy of self-reported COVID-19 vaccination status compared with a public health vaccination registry in Québec: Observational Diagnostic Study. JMIR Public Health Surveill. 2023 Jun 16;9:e44465. doi:

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

A CITF-funded study, published in JMIR Public Health Surveillance, found that self-reported COVID-19 vaccination status, when compared with the Québec Vaccination Registry as a reference standard, was accurate in 96% of cases. This means most patients were able to correctly report whether they had been vaccinated or not. This study was led by Dr. Patrick Archambault (Université Laval) in collaboration with Dr. Corinne Hohl (University of British Columbia).

The study enrolled consecutive consenting patients presenting to four emergency departments in Québec between March 24, 2020 and December 25, 2021 who had a positive COVID-19 test and who were already in the Quebec Vaccination Registry. Information collected from patients included the number of vaccine doses, brand, and time of vaccine administration.

Key findings:

  • There were high measures of accuracy (96%), sensitivity (98%), and specificity (92%) for self-reported vaccination status compared with the Québec Vaccination Registry as the reference standard.
  • The number of vaccine doses people reported to have received and the number of doses recorded in the vaccine registry were highly similar.
  • The self-reported vaccine brand and the recorded brand in the vaccine registry for the first dose were very similar, were moderately similar for the second dose, and not very similar for the third dose.
  • The self-reported vaccination status and the recorded vaccination status in the registry at phone follow-up and at their index ED visit were highly similar.

The study shows that most adult patients without cognitive disorders can accurately report their COVID-19 vaccination status, as well as the number of doses received and the vaccine brand. These findings suggest self-reported vaccination data can be used by researchers and policy makers to guide future studies and policies. However, in some cases, access to official electronic vaccine registries is still necessary to determine vaccination status, particularly in populations where self-reported data may be missing or difficult to obtain.

This diagnostic accuracy study was completed by the Canadian COVID-19 Emergency Department Rapid Response Network (CCEDRRN) using only data collected from 4 sites in the province of Québec because access to government electronic vaccine registries in the other provinces of Canada was unavailable.