Table 1

Characteristics of the study population (n=15 122)

n%*
Sex
Women809950.9
Men702349.1
Age group (years)
18–34280525.0
35–49355322.7
50–64494527.6
65–79312618.4
80+6936.4
Education
Low326731.0
Middle632641.9
High491627.1
Missing613–
Income
<60% of median152415.2
60%−<150% of median840657.6
≥150% of median506527.2
Missing127–
Date of participation
October 20205532(36.6)
November 20206748(44.6)
December 20202090(13.8)
January 2021595(3.9)
February 2021157(1.0)
SARS-CoV-2 IgG antibodies
Seropositive1921.3
Seronegative14 58998.7
Missing341–
SARS-CoV-2 RNA
PCR positive510.4
PCR negative14 63899.6
Missing433–
Previously tested positive for SARS-CoV-2†
Yes1461.1
No14 77198.9
Missing205–

  • *Weighted percentage (unweighted percentage in brackets).

  • †Self-reported positive throat swab test before study participation.