Table 3 Prevalence ratios for self-reported characteristics of tested individuals in phone and paper-based surveys.

From: Seroprevalence of SARS-CoV-2 antibodies in Saint Petersburg, Russia: a population-based study

 

CMIA

ELISA

Crude PR

95% CI

Adjusted PR

95% CI %

Crude PR

95% CI

Adjusted PR

95% CI %

Age group

18–34

1.00

Ref

1.00

Ref

1.00

Ref

1.00

Ref

35–49

0.66

(0.41–1.04)

0.59

(0.35–0.98)

0.82

(0.50–1.33)

0.79

(0.46–1.33)

50–64

1.00

(0.62–1.58)

1.00

(0.54–1.78)

1.34

(0.81–2.17)

1.38

(0.74–2.47)

65+

0.24

(0.04–0.77)

0.30

(0.02–1.45)

0.47

(0.11–1.29)

0.84

(0.13–2.89)

Male

1.14

(0.77–1.67)

1.07

(0.66–1.70)

1.04

(0.69–1.56)

0.93

(0.56–1.51)

Higher education

0.85

(0.54–1.41)

0.61

(0.36–1.06)

0.98

(0.60–1.71)

0.70

(0.41–1.29)

Higher income

1.07

(0.73–1.57)

1.05

(0.67–1.65)

1.17

(0.78–1.75)

1.11

(0.70–1.78)

Respondent lives alone

0.60

(0.32–1.02)

0.59

(0.28–1.09)

0.67

(0.36–1.16)

0.63

(0.30–1.19)

Respondent started to wash hands more often

0.63

(0.43–0.93)

0.58

(0.38–0.91)

0.65

(0.44–0.99)

0.64

(0.41–1.02)

Respondent travelled abroad in the last 3 months

1.05

(0.56–1.81)

0.84

(0.41–1.54)

0.98

(0.49–1.75)

0.73

(0.33–1.40)

History of COVID-19 testing

2.68

(1.82–3.92)

2.05

(1.30–3.20)

3.23

(2.16–4.81)

2.41

(1.51–3.81)

Cold symptoms in the last 3 months *

4.32

(2.70–7.19)

3.79

(2.30–6.54)

4.42

(2.71–7.57)

4.13

(2.45–7.34)

Smoking status

Never smoked

1.00

Ref

1.00

Ref

1.00

Ref

1.00

Ref

Previous smoker

0.87

(0.53–1.37)

0.94

(0.55–1.54)

0.83

(0.50–1.33)

0.94

(0.55–1.57)

Current smoker

0.54

(0.27–0.97)

0.46

(0.22–0.87)

0.42

(0.19–0.81)

0.34

(0.14–0.72)

Alcohol consumption frequency

Never

1.00

Ref

1.00

Ref

1.00

Ref

1.00

Ref

Monthly

1.21

(0.73–2.10)

1.31

(0.76–2.34)

1.11

(0.66–1.93)

1.19

(0.68–2.14)

Weekly or more often

0.92

(0.52–1.67)

0.96

(0.52–1.80)

0.82

(0.45–1.50)

0.94

(0.50–1.80)

Chronic diseases or medication use

0.86

(0.56–1.30)

0.84

(0.52–1.33)

0.77

(0.49–1.19)

0.69

(0.42–1.12)

Past history of allergies

0.53

(0.30–0.90)

0.54

(0.30–0.92)

0.50

(0.27–0.86)

0.53

(0.28–0.93)

  1. * – “Cold symptoms in the last 3 months” was used in the paper-based survey instead of “Past history of illness in the last 3 months” in the phone-based interview.