Table 1.
Characteristics of the assessed participants and results of univariable regression models comparing patients with positive serological tests vs. those with negative results – data from 1696 municipal employees of 2 cities in Northern Portugal, assessed May 15–June 19, 2020
| Variable | Participants (N = 1696) | OR (95% CI) | p | |
|---|---|---|---|---|
| total | with positive serological test (N = 50) | |||
| Age [years] (M±SD) | 46.1±11.0 | 45.2±11.9 | 1.0 (1.0–1.0) | 0.568 |
| Gender [n (%)] | ||||
| males | 1256 (74.1) | 29 (58.0) | 0.5 (0.3–0.8) | 0.007 |
| females | 440 (25.9) | 21 (42.0) | ||
| Cohabitation with a healthcare professional [n (%)] | 199 (11.7) | 6 (12.0) | 1.0 (0.4–2.5) | 0.934 |
| Occupation [n (%)] | ||||
| firefighter | 373 (22.0) | 10 (20.0) | 0.9 (0.4–1.8) | 0.727 |
| police officer | 177 (10.4) | 6 (12.0) | 1.2 (0.5–2.8) | 0.716 |
| administrative assistant | 137 (8.1) | 7 (14.0) | 1.9 (0.8–4.3) | 0.126 |
| maintenance worker | 174 (10.3) | 5 (10.0) | 1.0 (0.4–2.5) | 0.949 |
| Direct contact with COVID-19+ patients in professional activity [n (%)] | 355 (21.0) | 14 (28.0) | 1.5 (0.8–2.8) | 0.222 |
| Use of mask in professional activity [n (%)] | 1633 (96.3) | 49 (98.0) | 1.9 (0.3–13.9) | 0.533 |
| since March or before | 990 (58.4) | 27 (54.0) | 1.7 (0.2–12.8) | 0.601 |
| since April | 249 (14.7) | 9 (18.0) | 2.3 (0.3–18.4) | 0.437a |
| since May | 394 (23.2) | 13 (26.0) | 2.1 (0.3–16.2) | 0.484a |
| Confirmed COVID-19 case in the household [n (%)] | 41 (2.4) | 12 (24.0) | 17.4 (8.3–36.8) | <0.001 |
| Possible risk exposure/contact [n (%)] | 150 (8.8) | 25 (16.7) | 12.2 (6.8–21.8) | <0.001 |
| at work | 70 (4.1) | 8 (11.4) | 4.9 (2.2–10.8) | <0.001 |
| in national or international travels | 10 (0.6) | 1 (10.0) | 3.7 (0.7–19.9) | 0.218 |
| with a family member | 49 (2.9) | 11 (22.4) | 12.0 (5.7–25.1) | <0.001 |
a
Reference group consisting of those patients who did not wear a mask in their professional activity.
Bolded are p-values <0.05.