Table 2. Conditional logistic multivariable regression models for severe COVID-19 disease and SARS-CoV-2 infection in relation to the different dimensions of transmission and mitigation factors. [OR=odds ratio; CI=confidence interval.].
| Transmission and mitigation factors |
Severe COVID-19 disease N=5985 |
SARS-CoV-2 infection N=561 582 |
||||
|---|---|---|---|---|---|---|
| Matched a | Adjusted b | Matched a | ||||
| OR (95% CI) | OR (95% CI) | OR (95% CI) | ||||
| Number of workers in close proximity to each other (per day) | ||||||
| <10 | 1.10 (1.01–1.19) | 0.95 (0.87–1.03) | 1.01 (1.00–1.02) | |||
| 10–30 | 1.54 (1.41–1.68) | 1.20 (1.09–1.32) | 1.21 (1.19–1.22) | |||
| >30 | 1.69 (1.55–1.84) | 1.36 (1.24–1.49) | 1.36 (1.35–1.37) | |||
| Nature of contacts | ||||||
| In workspaces with coworkers only | 1.13 (1.04–1.22) | 0.98 (0.90–1.07) | 1.07 (1.06–1.08) | |||
| In workspaces with the general public | 1.51 (1.39–1.64) | 1.23 (1.13–1.35) | 1.22 (1.21–1.23) | |||
| Regular contacts with infected patients | 1.86 (1.68–2.05) | 1.37 (1.23–1.52) | 1.37 (1.35–1.38) | |||
| Contaminated workspaces | ||||||
| Frequently sharing materials/surfaces with coworkers (≥10 times/day) | 1.12 (1.03–1.21) | 1.00 (0.92–1.09) | 1.09 (1.08–1.10) | |||
| Sometimes sharing materials/surfaces with the general public (<10 times/day) | 1.10 (0.94–1.28) | 1.04 (0.88–1.22) | 1.01 (1.00–1.03) | |||
| Frequently sharing materials/surfaces with the general public (≥10 times/day) | 1.71 (1.58–1.85) | 1.30 (1.19–1.41) | 1.28 (1.27–1.29) | |||
| Work location | ||||||
| Mostly outside | 0.90 (0.67 – 1.21) | 0.77 (0.57 – 1.06) | 0.83 (0.80 – 0.86) | |||
| Partly inside | 0.94 (0.82–1.08) | 0.84 (0.72–0.97) | 1.04 (1.02–1.05) | |||
| Mostly inside | 1.43 (1.33–1.53) | 1.17 (1.08–1.26) | 1.19 (1.18–1.20) | |||
| Social distancing | ||||||
| Always maintained | 1.17 (1.08–1.27) | 1.05 (0.96–1.14) | 1.09 (1.08–1.09) | |||
| Not always possible | 1.33 (1.22–1.45) | 1.09 (0.99–1.20) | 1.18 (1.17–1.19) | |||
| Never maintained | 1.77 (1.62–1.93) | 1.32 (1.21–1.45) | 1.29 (1.28–1.31) | |||
| Physical proximity | ||||||
| 3rd versus 2nd and 1st | 1.21 (1.12–1.30) | 1.12 (1.04–1.21) | 1.13 (1.12–1.14) | |||
| 4th versus 2nd and 1st | 1.86 (1.71–2.03) | 1.47 (1.34–1.61) | 1.38 (1.37–1.40) | |||
| Exposure to diseases or infections | ||||||
| 2nd versus 1st | 1.48 (1.38–1.60) | 1.22 (1.13–1.32) | 1.13 (1.12–1.14) | |||
| 3rd versus 1st | 1.68 (1.66–2.10) | 1.44 (1.31–1.59) | 1.42 (1.41–1.44) | |||
| 4th versus 1st | 1.87 (1.66–2.10) | 1.72 (1.52–1.96) | 1.44 (1.42–1.45) | |||
a Models matched for age, gender, and region. b Models matched for age, gender, region, and adjusted for education, country of birth, dwelling area/inhabitants, number of inhabitants in the dwelling, chronic obstructive pulmonary disease, ischemic heart disease, diabetes, and dispensed corticosteroids.