Table 1

Seroprevalence of antibodies to SARS-CoV-2 by sociodemographic and other participant characteristics

OverallnPositive (%)
438370 (84.5)
Variablesn (%)Positive(% (95% CI))P (χ2 test)
Age (years)
≤1721 (4.8)14(3.2 (1.54 to 4.9))0.0670
18–30173 (39.5)146(33.3 (28.9 to 37.8))
31–50174 (39.7)153(34.9 (30.5 to 39.4))
>5070 (16)57(13.0 (9.9 to 16.2))
Sex
Female281 (64.2)241(55.0 (50.3 to 59.7))0.3185
Male157 (35.8)129(29.5 (25.2 to 33.7))
Employment status (undisclosed was not included in the calculation of significance)
Unemployed164 (39.1)137(31.4 (27.0 to 35.7))0.0176
Self-employed102 (24.3)82(18.8 (15.1 to 22.4))
Casual/part time88 (21.0)83(19.0 (15.3 to 22.7))
Student34 (8.1)27(6.2 (3.9 to 8.4))
Formal/regular31 (7.4)28(6.4 (4.1 to 8.7))
Not applicable (<16 years)1812(2.7 (1.2 to 4.3))
Undisclosed11(0.23)
Underlying health conditions
No341 (77.9)287(65.5 (61.1 to 70.0))0.7364
Yes97 (22.1)83(19.0 (15.3 to 22.6))
Types of underlying health conditions(% of all participants)
Cardiovascular disease40 (9.1)32(7.3 (4.9 to 9.8))0.4123
Stomach ulcer25 (5.7)20(4.6 (2.6 to 6.5))0.5246
HIV18 (4.1)17(3.9 (2.1 to 5.7))0.2330
Respiratory disease14 (3.2)12(2.7 (1.2 to 4.3))0.8964
Diabetes11 (2.5)10(2.3 (0.9 to 3.7))0.5506
On medication
No343 (78.3)291(66.4 (62.0 to 70.9))0.6888
Yes95 (21.7)79(18.0 (14.4 to 21.7))
COVID-19 symptoms (previous 16 months)
No157 (35.8)142(32.4 (28.0 to 36.8))0.0099
Yes281 (64.2)228(52.1 (47.4 to 56.8))
Ever tested for SARS-CoV-2
No371 (84.7)311(71.0 (66.7 to 75.3))0.3787
Yes67 (15.3)59 (10.3 to 16.7)
Previous SARS-CoV-2 test
Tested with negative result54 (80.6)48(71.6 (60.6 to 82.7))*
Tested with positive result4 (6.0)4(6.0 (0.1 to 11.8))
Tested with unknown result9 (13.4)7(10.4 (2.0 to 18.0))
COVID-19 vaccination
No408 (93.2)341(77.9 (74.0 to 81.8))0.0561
Yes30 (6.8)29(6.6 (4.3 to 9.0))
  • *No χ2 possible due to a negative value in the tested negative category.