Table 3.
Risk factor analysis for SARS-CoV-2 seropositivity among all participants (n=3100; full case analysis) in the PICO-study, first round of inclusion
| % SARS-CoV-2 seropositive | Univariable model* | Multivariable model | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ntotal | n | % | OR | 95% CI | P value | Adjusted OR | 95% CI | P value | ||||
| Age group | 0.016 | 0.105 | ||||||||||
| 2–12 | 457 | 4 | 0.9 | Ref. | Ref. | |||||||
| 13–17 | 129 | 1 | 0.8 | 0.88 | 0.10 | 7.91 | 0.87 | 0.10 | 7.91 | |||
| 18–24 | 226 | 12 | 5.3 | 6.47 | 2.05 | 20.43 | 4.52 | 1.40 | 14.58 | |||
| 25–39 | 696 | 24 | 3.5 | 4.17 | 1.43 | 12.14 | 3.10 | 1.05 | 9.14 | |||
| 40–49 | 429 | 11 | 2.6 | 3.05 | 0.96 | 9.68 | 2.48 | 0.77 | 7.98 | |||
| 50–59 | 485 | 8 | 1.7 | 1.94 | 0.58 | 6.49 | 1.49 | 0.44 | 5.07 | |||
| 60–69 | 377 | 7 | 1.9 | 2.16 | 0.63 | 7.44 | 1.71 | 0.49 | 5.98 | |||
| 70–90 | 301 | 7 | 2.3 | 2.64 | 0.76 | 9.14 | 2.46 | 0.70 | 8.60 | |||
| Sex | 0.81 | 0.57 | ||||||||||
| Men | 1368 | 32 | 2.3 | Ref. | Ref. | |||||||
| Women | 1732 | 42 | 2.4 | 1.06 | 0.66 | 1.71 | 1.15 | 0.71 | 1.88 | |||
| Region† | 0.64 | 0.36 | ||||||||||
| North | 537 | 7 | 1.3 | Ref. | Ref. | |||||||
| Mid-West | 411 | 11 | 2.7 | 2.14 | 0.80 | 5.72 | 2.27 | 0.86 | 5.98 | |||
| Mid-East | 494 | 14 | 2.8 | 2.27 | 0.89 | 5.80 | 2.00 | 0.79 | 5.04 | |||
| South-West | 451 | 11 | 2.4 | 1.83 | 0.69 | 4.86 | 1.80 | 0.69 | 4.74 | |||
| South-East | 652 | 17 | 2.6 | 2.04 | 0.82 | 5.07 | 2.08 | 0.85 | 5.12 | |||
| LVC | 555 | 14 | 2.5 | 1.80 | 0.71 | 4.61 | 1.09 | 0.40 | 2.94 | |||
| Orthodox-Reformed Protestant | 0.001 | 0.0007 | ||||||||||
| No | 2972 | 65 | 2.2 | Ref. | Ref. | |||||||
| Yes | 128 | 9 | 7.0 | 4.04 | 1.72 | 9.48 | 4.50 | 1.89 | 10.74 | |||
| Had been in contact with a COVID-19 confirmed case | <0.0001 | <0.0001 | ||||||||||
| No | 2074 | 33 | 1.6 | Ref. | Ref. | |||||||
| Yes | 192 | 16 | 8.3 | 4.65 | 2.44 | 8.87 | 4.97 | 2.58 | 9.56 | |||
| Don’t know | 834 | 25 | 3.0 | 1.75 | 1.03 | 2.99 | 1.88 | 1.10 | 3.22 | |||
| Took immunosuppressants, last month | 0.006 | 0.001 | ||||||||||
| No | 3039 | 69 | 2.3 | Ref. | Ref. | |||||||
| Yes | 61 | 5 | 8.2 | 3.94 | 1.50 | 10.39 | 5.05 | 1.89 | 13.48 | |||
| Took antibiotics/antiviral medication, last month | 0.01 | |||||||||||
| No | 2901 | 64 | 2.2 | Ref. | ||||||||
| Yes | 199 | 10 | 5.0 | 2.43 | 1.21 | 4.89 | ||||||
*Variables that were not associated with SARS-CoV-2 seropositivity in univariable analyses (ie, p≥0.10)—or that were not controlled for—included: ethnic background, (maternal) educational level, household size, (parent with a) contact profession, healthcare worker, number of persons contacted yesterday, working from home (normally and in the last week (during lockdown)), comorbidities (combining chronic lung disease, diabetes, history of malignancy, immunodeficiency, cardio-vascular disease, kidney disease), and use of blood pressure medication, immunosuppressants, statins and antivirals/antibiotics in the last month.
†Region North comprised provinces Groningen, Friesland, Drenthe and Overijssel, region Mid-West provinces Noord-Holland and Flevoland, region Mid-West provinces Utrecht and Gelderland, region South-West provinces Zuid-Holland and Zeeland, and region South-East provinces Noord-Brabant and Limburg.
CI, Confidence interval; LVC, Low vaccination coverage municipalities; OR, Odd ratio; Ref., Reference category.