Table 3.
Prevalence ratios for self-reported characteristics of tested individuals in phone and paper-based surveys.
| 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) |
* – “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.