The Corona Immunitas Digital Follow-Up eCohort to Monitor Impacts of the SARS-CoV-2 Pandemic in Switzerland: Study Protocol and First Results

Alexandre Speierer; Patricia O Chocano-Bedoya; Daniela Anker; Alexia Schmid; Dirk Keidel; Thomas Vermes; Medea Imboden; Sara Levati; Giovanni Franscella; Laurie Corna; Rebecca Amati; Erika Harju; Chantal Luedi; Gisela Michel; Caroline Veys-Takeuchi; Claire Zuppinger; Semira Gonseth Nusslé; Valérie D'Acremont; Ismaël Tall; Éric Salberg; Hélène Baysson; Elsa Lorthe; Francesco Pennacchio; Anja Frei; Marco Kaufmann; Marco Geigges; Erin Ashley West; Nathalie Schwab; Stéphane Cullati; Arnaud Chiolero; Christian Kahlert; Silvia Stringhini; Fabian Vollrath; Nicole Probst-Hensch; Nicolas Rodondi; Milo A Puhan; Viktor von Wyl

doi:10.3389/ijph.2022.1604506

The Corona Immunitas Digital Follow-Up eCohort to Monitor Impacts of the SARS-CoV-2 Pandemic in Switzerland: Study Protocol and First Results

Int J Public Health. 2022 Feb 28:67:1604506. doi: 10.3389/ijph.2022.1604506. eCollection 2022.

Authors

Alexandre Speierer^{1

2}, Patricia O Chocano-Bedoya^{1

3}, Daniela Anker³, Alexia Schmid⁴, Dirk Keidel^{5

6}, Thomas Vermes^{5

6}, Medea Imboden^{5

6}, Sara Levati⁷, Giovanni Franscella⁸, Laurie Corna⁸, Rebecca Amati⁸, Erika Harju⁹, Chantal Luedi⁹, Gisela Michel⁹, Caroline Veys-Takeuchi¹⁰, Claire Zuppinger¹⁰, Semira Gonseth Nusslé¹⁰, Valérie D'Acremont¹¹, Ismaël Tall¹², Éric Salberg¹², Hélène Baysson^{13

14}, Elsa Lorthe¹⁴, Francesco Pennacchio¹⁴, Anja Frei¹⁵, Marco Kaufmann¹⁵, Marco Geigges¹⁵, Erin Ashley West¹⁵, Nathalie Schwab^{1

2}, Stéphane Cullati^{3

16}, Arnaud Chiolero^{3

17}, Christian Kahlert^{18

19}, Silvia Stringhini^{13

14

20}, Fabian Vollrath²¹, Nicole Probst-Hensch^{5

6}, Nicolas Rodondi^{1

2}, Milo A Puhan¹⁵, Viktor von Wyl²²

Affiliations

¹ Institute of Primary Health Care (BIHAM), University of Bern, Bern, Switzerland.
² Department of General Internal Medicine, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.
³ Population Health Laboratory (#PopHealthLab), University of Fribourg, Fribourg, Switzerland.
⁴ Institute of Family Medicine, University of Fribourg, Fribourg, Switzerland.
⁵ Department of Epidemiology and Public Health, Swiss Tropical and Public Health Institute, Basel, Switzerland.
⁶ University of Basel, Basel, Switzerland.
⁷ Department of Business Economics, Health and Social Care, University of Applied Sciences and Arts of Southern Switzerland, Lugano, Switzerland.
⁸ Institute of Public Health, Faculty of BioMedicine, Università Della Svizzera Italiana, Lugano, Switzerland.
⁹ Department of Health Sciences and Medicine, University of Luzern, Luzern, Switzerland.
¹⁰ Department of Epidemiology and Health Systems, Center for Primary Care and Public Health (Unisanté), Lausanne University, Lausanne, Switzerland.
¹¹ Department of Research and Innovation, Center for Primary Care and Public Health (Unisanté), Lausanne University, Lausanne, Switzerland.
¹² Cantonal Public Health Service, Neuchâtel, Switzerland.
¹³ Department of Health and Community Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
¹⁴ Unit of Population Epidemiology, Division of Primary Care Medicine, Geneva University Hospitals, Geneva, Switzerland.
¹⁵ Epidemiology, Biostatistics and Prevention Institute, Zurich, Switzerland.
¹⁶ Department of Readaptation and Geriatrics, University of Geneva, Geneva, Switzerland.
¹⁷ School of Population and Global Health, McGill University, Montreal, QC, Canada.
¹⁸ Department of Infectious Diseases and Hospital Epidemiology, Cantonal Hospital St. Gallen, St. Gallen, Switzerland.
¹⁹ Infectious Diseases and Hospital Epidemiology, Children's Hospital of Eastern Switzerland, St. Gallen, Switzerland.
²⁰ University Center for General Medicine and Public Health, University of Lausanne, Lausanne, Switzerland.
²¹ Corona Immunitas Program Management Group, Swiss School of Public Health, Zurich, Switzerland.
²² Institute for Implementation Science in Health Care, University of Zurich, Zurich, Switzerland.

Abstract

Objectives: To describe the rationale, organization, and procedures of the Corona Immunitas Digital Follow-Up (CI-DFU) eCohort and to characterize participants at baseline. Methods: Participants of Corona Immunitas, a population-based nationwide SARS-CoV-2 seroprevalence study in Switzerland, were invited to join the CI-DFU eCohort in 11 study centres. Weekly online questonnaires cover health status changes, prevention measures adherence, and social impacts. Monthly questionnaires cover additional prevention adherence, contact tracing apps use, vaccination and vaccine hesitancy, and socio-economic changes. Results: We report data from the 5 centres that enrolled in the CI-DFU between June and October 2020 (covering Basel City/Land, Fribourg, Neuchâtel, Ticino, Zurich). As of February 2021, 4636 participants were enrolled and 85,693 weekly and 27,817 monthly questionnaires were collected. Design-based oversampling led to overrepresentation of individuals aged 65+ years. People with higher education and income were more likely to enroll and be retained. Conclusion: Broad enrolment and robust retention of participants enables scientifically sound monitoring of pandemic impacts, prevention, and vaccination progress. The CI-DFU eCohort demonstrates proof-of-principle for large-scale, federated eCohort study designs based on jointly agreed principles and transparent governance.

Keywords: SARS-CoV-2; digital follow-up; eCohort; population-based study; prevention; public health surveillance.

Copyright © 2022 Speierer, Chocano-Bedoya, Anker, Schmid, Keidel, Vermes, Imboden, Levati, Franscella, Corna, Amati, Harju, Luedi, Michel, Veys-Takeuchi, Zuppinger, Nusslé, D’Acremont, Tall, Salberg, Baysson, Lorthe, Pennacchio, Frei, Kaufmann, Geigges, West, Schwab, Cullati, Chiolero, Kahlert, Stringhini, Vollrath, Probst-Hensch, Rodondi, Puhan and von Wyl.

MeSH terms

Aged
COVID-19* / epidemiology
COVID-19* / prevention & control
Follow-Up Studies
Humans
Pandemics
SARS-CoV-2*
Seroepidemiologic Studies
Switzerland / epidemiology