Table 1.
Characteristics of participants with symptoms tested for SARS-CoV-2 between 14 December 2020 and 19 April 2021 in Ontario, Canada. Values are numbers (percentages) unless stated otherwise
| Characteristics | SARS-CoV-2 status | Standardised difference* | Vaccination status | Standardised difference* | ||
|---|---|---|---|---|---|---|
| Positive (n=53 270) | Negative (n=270 763) | ≥1 dose mRNA vaccine (n=21 272) | Unvaccinated (n=302 761) | |||
| Vaccine dose: | ||||||
| At least 1 | 2050 (3.8) | 19 222 (7.1) | - | - | - | - |
| 2 | 73 (0.1) | 4821 (1.8) | - | - | - | - |
| Positivity to SARS-CoV-2 type: | - | - | - | 2050 (9.6) | 51 220 (16.9) | - |
| Earlier variant | - | - | - | 579 (2.7) | 27 510 (9.1) | - |
| Alpha (B.1.1.7) | - | - | - | 807 (3.8) | 12 282 (4.1) | - |
| Beta (B.1.351) or gamma (P.1) (variants with E484K mutation) | - | - | - | 98 (0.5) | 1291 (0.4) | - |
| Mean (SD) age (years) | 42.4 (17.1) | 43.2 (17.8) | 0.04 | 51.8 (20.8) | 42.4 (17.3) | 0.49 |
| Age group (years): | ||||||
| 16-29 | 15 175 (28.5) | 72 238 (26.7) | 0.04 | 3457 (16.3) | 83 956 (27.7) | 0.28 |
| 30-39 | 10 024 (18.8) | 59 326 (21.9) | 0.08 | 4011 (18.9) | 65 339 (21.6) | 0.07 |
| 40-49 | 9642 (18.1) | 46 225 (17.1) | 0.03 | 3287 (15.5) | 52 580 (17.4) | 0.05 |
| 50-59 | 9460 (17.8) | 40 874 (15.1) | 0.07 | 3112 (14.6) | 47 222 (15.6) | 0.03 |
| 60-69 | 5279 (9.9) | 27 342 (10.1) | 0.01 | 2261 (10.6) | 30 360 (10.0) | 0.02 |
| 70-79 | 2426 (4.6) | 14 888 (5.5) | 0.04 | 2272 (10.7) | 15 042 (5.0) | 0.21 |
| ≥80 | 1264 (2.4) | 9870 (3.6) | 0.07 | 2872 (13.5) | 8262 (2.7) | 0.40 |
| Males | 25 993 (48.8) | 112 501 (41.5) | 0.15 | 6013 (28.3) | 132 481 (43.8) | 0.33 |
| Public health unit region†: | ||||||
| Central East | 2624 (4.9) | 29 194 (10.8) | 0.22 | 1969 (9.3) | 29 849 (9.9) | 0.02 |
| Central West | 8322 (15.6) | 48 419 (17.9) | 0.06 | 3853 (18.1) | 52 888 (17.5) | 0.02 |
| Durham | 1433 (2.7) | 8583 (3.2) | 0.03 | 522 (2.5) | 9494 (3.1) | 0.04 |
| Eastern | 689 (1.3) | 15 147 (5.6) | 0.24 | 1087 (5.1) | 14 749 (4.9) | 0.01 |
| North | 1753 (3.3) | 31 321 (11.6) | 0.32 | 2251 (10.6) | 30 823 (10.2) | 0.01 |
| Ottawa | 417 (0.8) | 3144 (1.2) | 0.04 | 446 (2.1) | 3115 (1.0) | 0.09 |
| Peel | 13 515 (25.4) | 32 981 (12.2) | 0.34 | 2395 (11.3) | 44 101 (14.6) | 0.10 |
| South West | 7562 (14.2) | 39 316 (14.5) | 0.01 | 3885 (18.3) | 42 993 (14.2) | 0.11 |
| Toronto | 12 458 (23.4) | 45 540 (16.8) | 0.16 | 3462 (16.3) | 54 536 (18.0) | 0.05 |
| York | 4278 (8.0) | 15 995 (5.9) | 0.08 | 1323 (6.2) | 18 950 (6.3) | 0.00 |
| Biweekly period of test: | ||||||
| 14 Dec 2020 to 27 Dec 2020 | 4139 (7.8) | 27 456 (10.1) | 0.08 | 13 (0.1) | 31 582 (10.4) | 0.48 |
| 28 Dec 2020 to 10 Jan 2021 | 6870 (12.9) | 26 993 (10.0) | 0.09 | 335 (1.6) | 33 528 (11.1) | 0.40 |
| 11 Jan 2021 to 24 Jan 2021 | 4864 (9.1) | 26 747 (9.9) | 0.03 | 1068 (5.0) | 30 543 (10.1) | 0.19 |
| 25 Jan 2021 to 7 Feb 2021 | 3539 (6.6) | 24 276 (9.0) | 0.09 | 1204 (5.7) | 26 611 (8.8) | 0.12 |
| 8 Feb 2021 to 21 Feb 2021 | 3595 (6.7) | 24 800 (9.2) | 0.09 | 1031 (4.8) | 27 364 (9.0) | 0.17 |
| 22 Feb 2021 to 7 Mar 2021 | 3539 (6.6) | 30 760 (11.4) | 0.17 | 1491 (7.0) | 32 808 (10.8) | 0.13 |
| 8 Mar 2021 to 21 Mar 2021 | 5134 (9.6) | 32 776 (12.1) | 0.08 | 2790 (13.1) | 35 120 (11.6) | 0.05 |
| 22 Mar 2021 to 4 Apr 2021 | 8338 (15.7) | 35 910 (13.3) | 0.07 | 4814 (22.6) | 39 434 (13.0) | 0.25 |
| 5 Apr 2021 to 19 Apr 2021 | 13 252 (24.9) | 41 045 (15.2) | 0.24 | 8526 (40.1) | 45 771 (15.1) | 0.58 |
| No of tests in past three months: | ||||||
| 0 | 43 713 (82.1) | 189 786 (70.1) | 0.28 | 11 588 (54.5) | 221 911 (73.3) | 0.40 |
| 1 | 7151 (13.4) | 54 827 (20.2) | 0.18 | 4338 (20.4) | 57 640 (19.0) | 0.03 |
| ≥2 | 2406 (4.5) | 26 150 (9.7) | 0.20 | 5346 (25.1) | 23 210 (7.7) | 0.49 |
| Any comorbidity‡ | 23 212 (43.6) | 127 974 (47.3) | 0.07 | 12 218 (57.4) | 138 968 (45.9) | 0.23 |
| 2019-2020 and/or 2020-21 influenza vaccine | 13 751 (25.8) | 89 395 (33.0) | 0.16 | 9587 (45.1) | 93 559 (30.9) | 0.30 |
| Household income fifth†§: | ||||||
| 1 (lowest) | 11 878 (22.3) | 47 944 (17.7) | 0.11 | 3750 (17.6) | 56 072 (18.5) | 0.02 |
| 2 | 11 154 (20.9) | 51 470 (19.0) | 0.05 | 4146 (19.5) | 58 478 (19.3) | 0.00 |
| 3 | 11 477 (21.5) | 52 628 (19.4) | 0.05 | 4233 (19.9) | 59 872 (19.8) | 0.00 |
| 4 | 10 146 (19.0) | 56 676 (20.9) | 0.05 | 4513 (21.2) | 62 309 (20.6) | 0.02 |
| 5 (highest) | 8359 (15.7) | 60 774 (22.4) | 0.17 | 4540 (21.3) | 64 593 (21.3) | 0.00 |
| Essential workers fifth (%)†¶: | ||||||
| 1 (0-32.5) | 6440 (12.1) | 50 664 (18.7) | 0.18 | 3917 (18.4) | 53 187 (17.6) | 0.02 |
| 2 (32.5-42.3) | 11 225 (21.1) | 60 040 (22.2) | 0.03 | 4664 (21.9) | 66 601 (22.0) | 0.00 |
| 3 (42.3–49.8) | 11 106 (20.8) | 56 108 (20.7) | 0.00 | 4468 (21.0) | 62 746 (20.7) | 0.01 |
| 4 (50.0-57.5) | 11 576 (21.7) | 52 849 (19.5) | 0.05 | 4211 (19.8) | 60 214 (19.9) | 0.00 |
| 5 (57.5-100) | 12 519 (23.5) | 49 067 (18.1) | 0.13 | 3859 (18.1) | 57 727 (19.1) | 0.02 |
| No (range) of people per dwelling fifth†: | ||||||
| 1 (0–2.1) | 5781 (10.9) | 51 852 (19.2) | 0.23 | 4277 (20.1) | 53 356 (17.6) | 0.06 |
| 2 (2.2–2.4) | 6641 (12.5) | 52 326 (19.3) | 0.19 | 4219 (19.8) | 54 748 (18.1) | 0.04 |
| 3 (2.5–2.6) | 5633 (10.6) | 37 229 (13.7) | 0.10 | 3020 (14.2) | 39 842 (13.2) | 0.03 |
| 4 (2.7–3.0) | 12 967 (24.3) | 63 774 (23.6) | 0.02 | 4874 (22.9) | 71 867 (23.7) | 0.02 |
| 5 (3.1–5.7) | 21 833 (41.0) | 63 459 (23.4) | 0.38 | 4709 (22.1) | 80 583 (26.6) | 0.10 |
| Self-identified visible minority fifth (%)† **: | ||||||
| 1 (0.0-2.2) | 4437 (8.3) | 51 919 (19.2) | 0.32 | 4133 (19.4) | 52 223 (17.2) | 0.06 |
| 2 (2.2-7.5) | 5752 (10.8) | 55 124 (20.4) | 0.27 | 4592 (21.6) | 56 284 (18.6) | 0.07 |
| 3 (7.5-18.7) | 7223 (13.6) | 51 122 (18.9) | 0.14 | 3982 (18.7) | 54 363 (18.0) | 0.02 |
| 4 (18.7-43.5) | 10 718 (20.1) | 53 691 (19.8) | 0.01 | 3974 (18.7) | 60 435 (20.0) | 0.03 |
| 5 (43.5-100) | 24 736 (46.4) | 56 876 (21.0) | 0.56 | 4438 (20.9) | 77 174 (25.5) | 0.11 |
Values >0.10 are considered clinically relevant.
Sum of counts does not equal column total because of individuals with missing information (<1.0%) for this characteristic.
Comorbidities include chronic respiratory diseases, chronic heart diseases, hypertension, diabetes, immunocompromising conditions due to underlying diseases or treatment, autoimmune diseases, chronic kidney disease, advanced liver disease, dementia/frailty, and history of stroke or transient ischaemic attack.
Includes variable cut-off values in each city/census area to account for cost of living. A dissemination area (DA) being in the first fifth means it is among the lowest 20% of DAs in its city by income.
Percentage of people in area working in sales and service occupations; trades, transport and equipment operators, and related occupations; natural resources, agriculture, and related production occupations; and occupations in manufacturing and utilities. Census counts for people are randomly rounded up or down to the nearest number divisible by 5, which results in some minor imprecision.
Percentage of people in area who self-identified as a visible minority. Census counts for people are randomly rounded up or down to the nearest number divisible by 5, which results in some minor imprecision.