Table 1. Characteristics of included participants in each study and overall.
| Characteristics | Number and percentage of participants in Onsite Testing Study N=2,128 |
Number and percentage of participants in Self-Testing Study N=627 |
Number and percentage of total participants N=2,755 |
p-value |
|---|---|---|---|---|
| Age, median (IQR), years | 48 (IQR: 37–57) | 48 (IQR: 34–57) | 48 (IQR: 37–57) | 0.477 |
| Business sector | ||||
| Manufacturing/supplier | 1,408 (66.2) | 298 (47.5) | 1,706 (61.9) | <0.001 |
| Retail/customer facing | 426 (20.0) | 90 (14.3) | 516 (18.7) | |
| Office | 181 (8.5) | 239 (38.1) | 420 (15.2) | |
| Childcare | 113 (5.3) | 0 (0) | 113 (4.1) | |
| Business size | ||||
| 1–50 employees | 895 (42.1) | 105 (16.7) | 1,000 (36.3) | <0.001 |
| More than 50 employees | 1,233 (57.9) | 522 (83.2) | 1,755 (63.7) | |
| Sex | ||||
| Male | 1,320 (62.0) | 281 (44.8) | 1,601 (58.1) | <0.001 |
| Female | 808 (38.0) | 346 (55.2) | 1,154 (41.9) | |
| Ethnicity | ||||
| White | 926 (43.5) | 302 (48.2) | 1,228 (44.6) | 0.0441 |
| Non-White | 1,202 (56.5) | 325 (51.8) | 1,527 (55.4) | |
| Income | ||||
| Highest 60% | 797 (37.4) | 254 (40.5) | 1,051 (38.1) | 0.181 |
| Lowest 40% | 1,331 (62.5) | 373 (59.5) | 1,704 (61.8) | |
| Any health factors | ||||
| No | 1,681 (79.0) | 457 (72.9) | 2,138 (77.6) | 0.0015 |
| Yes | 447 (21.0) | 170 (27.1) | 617 (22.4) | |
| Smoking history | ||||
| Never smoked | 1,668 (78.4) | 484 (77.2) | 2,152 (78.1) | 0.563 |
| Current/previous smoker | 460 (21.6) | 143 (22.8) | 603 (21.9) | |
| Recent travel outside of Montréala | ||||
| Yes | 50 (2.3) | 111 (17.7) | 161 (5.8) | <0.001 |
| No/not reported | 2,078 (97.6) | 516 (82.3) | 2,594 (94.1) | |
| Recent travel outside of Québeca | ||||
| Yes | 8 (0.4) | 15 (2.4) | 23 (0.8) | <0.001 |
| No/not reported | 2,120 (99.6) | 612 (97.6) | 2,732 (99.2) | |
| Any contact with a person with confirmed COVID-19 outside of the workplace? | ||||
| No | 1,878 (88.2) | 555 (88.5) | 2,433 (88.3) | <0.001 |
| Yes, previous (more than 14 days ago) |
222 (10.4) | 38 (6.1) | 260 (9.4) | |
| Yes, casual recent (within 14 days) |
28 (1.3) | 34 (5.4) | 62 (2.2) | |
| Previous testing for SARS-CoV-2 | ||||
| No | 1,155 (54.3) | 138 (22.0) | 1,293 (46.9) | <0.001 |
| Yes | 973 (45.7) | 489 (78.0) | 1,462 (53.1) | |
| Result was negative | 882 (41.4) | 450 (71.8) | 1,332 (48.3) | 0.438 |
| Result was positive | 91 (4.3) | 39 (6.2) | 130 (4.7) | |
| SARS-CoV-2 vaccinationb | ||||
| No | N/A | 68 (10.8) | N/A | N/A |
| Yes | N/A | 559 (89.1) | N/A | |
| One dose | N/A | 166 (26.5) | N/A | N/A |
| Two doses | N/A | 393 (62.7) | N/A | |
Abbreviations: IQR, interquartile range; N/A, not applicable
a Recent travel defined as occurring within the previous 14 days
b Information on vaccination only available for participants in the Self-Testing Study
Note: Two-sided p-values are calculated using Fisher exact or chi-squared test, as appropriate for categorical data and Wilcoxon rank sum or Kruskal-Wallis test for continuous data