Time trends in social contacts before and during the COVID-19 pandemic: the CONNECT study.
COVID-19
Infectious disease
Mathematical modeling
Public health
Social contacts
Social distancing measures
Journal
BMC public health
ISSN: 1471-2458
Titre abrégé: BMC Public Health
Pays: England
ID NLM: 100968562
Informations de publication
Date de publication:
23 05 2022
23 05 2022
Historique:
received:
13
10
2021
accepted:
04
05
2022
entrez:
23
5
2022
pubmed:
24
5
2022
medline:
26
5
2022
Statut:
epublish
Résumé
Since the beginning of the COVID-19 pandemic, many countries, including Canada, have adopted unprecedented physical distancing measures such as closure of schools and non-essential businesses, and restrictions on gatherings and household visits. We described time trends in social contacts for the pre-pandemic and pandemic periods in Quebec, Canada. CONNECT is a population-based study of social contacts conducted shortly before (2018/2019) and during the COVID-19 pandemic (April 2020 - February 2021), using the same methodology for both periods. We recruited participants by random digit dialing and collected data by self-administered web-based questionnaires. Questionnaires documented socio-demographic characteristics and social contacts for two assigned days. A contact was defined as a two-way conversation at a distance ≤ 2 m or as a physical contact, irrespective of masking. We used weighted generalized linear models with a Poisson distribution and robust variance (taking possible overdispersion into account) to compare the mean number of social contacts over time and by socio-demographic characteristics. A total of 1291 and 5516 Quebecers completed the study before and during the pandemic, respectively. Contacts significantly decreased from a mean of 8 contacts/day prior to the pandemic to 3 contacts/day during the spring 2020 lockdown. Contacts remained lower than the pre-COVID period thereafter (lowest = 3 contacts/day during the Christmas 2020/2021 holidays, highest = 5 in September 2020). Contacts at work, during leisure activities/in other locations, and at home with visitors showed the greatest decreases since the beginning of the pandemic. All sociodemographic subgroups showed significant decreases of contacts since the beginning of the pandemic. The mixing matrices illustrated the impact of public health measures (e.g. school closure, gathering restrictions) with fewer contacts between children/teenagers and fewer contacts outside of the three main diagonals of contacts between same-age partners/siblings and between children and their parents. Physical distancing measures in Quebec significantly decreased social contacts, which most likely mitigated the spread of COVID-19.
Sections du résumé
BACKGROUND
Since the beginning of the COVID-19 pandemic, many countries, including Canada, have adopted unprecedented physical distancing measures such as closure of schools and non-essential businesses, and restrictions on gatherings and household visits. We described time trends in social contacts for the pre-pandemic and pandemic periods in Quebec, Canada.
METHODS
CONNECT is a population-based study of social contacts conducted shortly before (2018/2019) and during the COVID-19 pandemic (April 2020 - February 2021), using the same methodology for both periods. We recruited participants by random digit dialing and collected data by self-administered web-based questionnaires. Questionnaires documented socio-demographic characteristics and social contacts for two assigned days. A contact was defined as a two-way conversation at a distance ≤ 2 m or as a physical contact, irrespective of masking. We used weighted generalized linear models with a Poisson distribution and robust variance (taking possible overdispersion into account) to compare the mean number of social contacts over time and by socio-demographic characteristics.
RESULTS
A total of 1291 and 5516 Quebecers completed the study before and during the pandemic, respectively. Contacts significantly decreased from a mean of 8 contacts/day prior to the pandemic to 3 contacts/day during the spring 2020 lockdown. Contacts remained lower than the pre-COVID period thereafter (lowest = 3 contacts/day during the Christmas 2020/2021 holidays, highest = 5 in September 2020). Contacts at work, during leisure activities/in other locations, and at home with visitors showed the greatest decreases since the beginning of the pandemic. All sociodemographic subgroups showed significant decreases of contacts since the beginning of the pandemic. The mixing matrices illustrated the impact of public health measures (e.g. school closure, gathering restrictions) with fewer contacts between children/teenagers and fewer contacts outside of the three main diagonals of contacts between same-age partners/siblings and between children and their parents.
CONCLUSION
Physical distancing measures in Quebec significantly decreased social contacts, which most likely mitigated the spread of COVID-19.
Identifiants
pubmed: 35606703
doi: 10.1186/s12889-022-13402-7
pii: 10.1186/s12889-022-13402-7
pmc: PMC9125550
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
1032Subventions
Organisme : Medical Research Council
ID : MR/R015600/1
Pays : United Kingdom
Informations de copyright
© 2022. The Author(s).
Références
Epidemiology. 2019 Sep;30(5):723-736
pubmed: 31274572
BMC Res Notes. 2020 Jun 16;13(1):293
pubmed: 32546245
Euro Surveill. 2021 Feb;26(8):
pubmed: 33632374
Sci Rep. 2020 Dec 14;10(1):21885
pubmed: 33318521
BMC Infect Dis. 2009 Nov 27;9:187
pubmed: 19943919
Science. 2020 Jun 26;368(6498):1481-1486
pubmed: 32350060
Biometrics. 1988 Dec;44(4):1049-60
pubmed: 3233245
BMC Infect Dis. 2014 Mar 10;14:136
pubmed: 24612900
BMJ Open. 2021 Oct 21;11(10):e050651
pubmed: 34675016
PLoS One. 2020 Aug 6;15(8):e0237128
pubmed: 32760114
BMC Infect Dis. 2021 Mar 18;21(1):274
pubmed: 33736606
PLoS One. 2015 Jul 15;10(7):e0133203
pubmed: 26176549
Epidemiology. 2021 Nov 1;32(6):781-791
pubmed: 34392254
PLoS Med. 2008 Mar 25;5(3):e74
pubmed: 18366252
BMC Public Health. 2021 Nov 8;21(1):2040
pubmed: 34749676
BMC Med. 2020 May 7;18(1):124
pubmed: 32375776
Epidemiol Infect. 2006 Dec;134(6):1158-66
pubmed: 16707031