Table 1.
Descriptive characteristics of community-dwelling adults aged ≥50 years tested for SARS-CoV-2 and with severe outcomes between January 2, 2022 and October 1, 2022 in Ontario, Canada, comparing Omicron-associated severe outcome cases to SARS-CoV-2 negative controls, stratified by age group
| Age 50–59 years | Age 60–69 years | Age 70–79 years | Age 80+ years | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SARS-CoV-2 negative controls, n (%)a | Omicron cases, n (%) | SDb | SARS-CoV-2 negative controls, n (%)a | Omicron cases, n (%) | SDb | SARS-CoV-2 negative controls, n (%)a | Omicron cases, n (%) | SDb | SARS-CoV-2 negative controls, n (%)a | Omicron cases, n (%) | SDb | |
| Total | 25,002 | 1136 | 16,139 | 1926 | 11,585 | 2975 | 10,154 | 5.123 | ||||
| Characteristics | ||||||||||||
| Age (years), mean (standard deviation) | 54.45 ± 2.91 | 55.15 ± 2.86 | 0.24 | 63.95 ± 2.85 | 64.78 ± 2.90 | 0.29 | 74.20 ± 2.81 | 74.79 ± 2.82 | 0.21 | 86.27 ± 4.79 | 86.96 ± 4.93 | 0.14 |
| Male sex | 7370 (29.5%) | 659 (58.0%) | 0.60 | 6,396 (39.6%) | 1,099 (57.1%) | 0.35 | 5,387 (46.5%) | 1,715 (57.6%) | 0.22 | 4,341 (42.8%) | 2,858 (55.8%) | 0.26 |
| Public health unit region | ||||||||||||
| Central East | 2232 (8.9%) | 62 (5.5%) | 0.13 | 1227 (7.6%) | 118 (6.1%) | 0.06 | 648 (5.6%) | 199 (6.7%) | 0.05 | 387 (3.8%) | 312 (6.1%) | 0.11 |
| Central West | 3794 (15.2%) | 224 (19.7%) | 0.12 | 2408 (14.9%) | 417 (21.7%) | 0.17 | 1815 (15.7%) | 593 (19.9%) | 0.11 | 1609 (15.8%) | 950 (18.5%) | 0.07 |
| Durham | 1552 (6.2%) | 48 (4.2%) | 0.09 | 829 (5.1%) | 52 (2.7%) | 0.13 | 375 (3.2%) | 88 (3.0%) | 0.02 | 133 (1.3%) | 121 (2.4%) | 0.08 |
| Eastern | 1356 (5.4%) | 105 (9.2%) | 0.15 | 621 (3.8%) | 168 (8.7%) | 0.20 | 347 (3.0%) | 265 (8.9%) | 0.25 | 310 (3.1%) | 394 (7.7%) | 0.21 |
| North | 4696 (18.8%) | 126 (11.1%) | 0.22 | 3428 (21.2%) | 183 (9.5%) | 0.33 | 2533 (21.9%) | 249 (8.4%) | 0.38 | 2180 (21.5%) | 378 (7.4%) | 0.41 |
| Ottawa | 599 (2.4%) | 57 (5.0%) | 0.14 | 274 (1.7%) | 83 (4.3%) | 0.15 | 166 (1.4%) | 147 (4.9%) | 0.20 | 187 (1.8%) | 240 (4.7%) | 0.16 |
| Peel | 2266 (9.1%) | 125 (11.0%) | 0.06 | 1670 (10.3%) | 212 (11.0%) | 0.02 | 1486 (12.8%) | 359 (12.1%) | 0.02 | 1613 (15.9%) | 579 (11.3%) | 0.13 |
| South West | 3961 (15.8%) | 165 (14.5%) | 0.04 | 2980 (18.5%) | 271 (14.1%) | 0.12 | 2425 (20.9%) | 409 (13.7%) | 0.19 | 2288 (22.5%) | 604 (11.8%) | 0.29 |
| Toronto | 3122 (12.5%) | 143 (12.6%) | 0.00 | 1888 (11.7%) | 286 (14.8%) | 0.09 | 1384 (11.9%) | 442 (14.9%) | 0.09 | 1234 (12.2%) | 1098 (21.4%) | 0.25 |
| York | 1329 (5.3%) | 74 (6.5%) | 0.05 | 760 (4.7%) | 129 (6.7%) | 0.09 | 382 (3.3%) | 210 (7.1%) | 0.17 | 169 (1.7%) | 432 (8.4%) | 0.31 |
| Missing | 95 (0.4%) | 7 (0.6%) | 0.03 | 54 (0.3%) | 7 (0.4%) | 0.00 | 24 (0.2%) | 14 (0.5%) | 0.05 | 44 (0.4%) | 15 (0.3%) | 0.02 |
| Household income quintile | ||||||||||||
| 1 (lowest) | 4645 (18.6%) | 337 (29.7%) | 0.26 | 3552 (22.0%) | 577 (30.0%) | 0.18 | 2574 (22.2%) | 824 (27.7%) | 0.13 | 2368 (23.3%) | 1248 (24.4%) | 0.02 |
| 2 | 4841 (19.4%) | 221 (19.5%) | 0.00 | 3331 (20.6%) | 426 (22.1%) | 0.04 | 2415 (20.8%) | 663 (22.3%) | 0.04 | 2291 (22.6%) | 1170 (22.8%) | 0.01 |
| 3 | 4955 (19.8%) | 216 (19.0%) | 0.02 | 3001 (18.6%) | 336 (17.4%) | 0.03 | 2215 (19.1%) | 552 (18.6%) | 0.01 | 1963 (19.3%) | 1024 (20.0%) | 0.02 |
| 4 | 5091 (20.4%) | 215 (18.9%) | 0.04 | 3053 (18.9%) | 332 (17.2%) | 0.04 | 2174 (18.8%) | 498 (16.7%) | 0.05 | 1797 (17.7%) | 885 (17.3%) | 0.01 |
| 5 (highest) | 5407 (21.6%) | 144 (12.7%) | 0.24 | 3152 (19.5%) | 250 (13.0%) | 0.18 | 2168 (18.7%) | 419 (14.1%) | 0.13 | 1687 (16.6%) | 785 (15.3%) | 0.04 |
| Missing | 63 (0.3%) | 3 (0.3%) | 0.00 | 50 (0.3%) | 5 (0.3%) | 0.01 | 39 (0.3%) | 19 (0.6%) | 0.04 | 48 (0.5%) | 11 (0.2%) | 0.04 |
| Essential workers quintile | ||||||||||||
| 1 (0%–32.5%) | 3941 (15.8%) | 110 (9.7%) | 0.18 | 2266 (14.0%) | 209 (10.9%) | 0.10 | 1782 (15.4%) | 382 (12.8%) | 0.07 | 1699 (16.7%) | 865 (16.9%) | 0.00 |
| 2 (32.5%–42.3%) | 5669 (22.7%) | 236 (20.8%) | 0.05 | 3354 (20.8%) | 361 (18.7%) | 0.05 | 2368 (20.4%) | 581 (19.5%) | 0.02 | 2230 (22.0%) | 1085 (21.2%) | 0.02 |
| 3 (42.3%–49.8%) | 5429 (21.7%) | 236 (20.8%) | 0.02 | 3535 (21.9%) | 420 (21.8%) | 0.00 | 2503 (21.6%) | 621 (20.9%) | 0.02 | 2264 (22.3%) | 1087 (21.2%) | 0.03 |
| 4 (50.0%–57.5%) | 5157 (20.6%) | 235 (20.7%) | 0.00 | 3440 (21.3%) | 437 (22.7%) | 0.03 | 2429 (21.0%) | 654 (22.0%) | 0.02 | 1938 (19.1%) | 1112 (21.7%) | 0.07 |
| 5 (57.5%–100%) | 4595 (18.4%) | 307 (27.0%) | 0.21 | 3403 (21.1%) | 483 (25.1%) | 0.09 | 2437 (21.0%) | 714 (24.0%) | 0.07 | 1962 (19.3%) | 953 (18.6%) | 0.02 |
| Missing | 211 (0.8%) | 12 (1.1%) | 0.02 | 141 (0.9%) | 16 (0.8%) | 0.00 | 66 (0.6%) | 23 (0.8%) | 0.02 | 61 (0.6%) | 21 (0.4%) | 0.03 |
| Persons per dwelling quintile | ||||||||||||
| 1 (0–2.1) | 4518 (18.1%) | 263 (23.2%) | 0.13 | 3647 (22.6%) | 489 (25.4%) | 0.07 | 3131 (27.0%) | 805 (27.1%) | 0.00 | 3268 (32.2%) | 1362 (26.6%) | 0.12 |
| 2 (2.2–2.4) | 5220 (20.9%) | 235 (20.7%) | 0.00 | 3682 (22.8%) | 396 (20.6%) | 0.05 | 2733 (23.6%) | 577 (19.4%) | 0.10 | 2344 (23.1%) | 958 (18.7%) | 0.11 |
| 3 (2.5–2.6) | 3480 (13.9%) | 168 (14.8%) | 0.02 | 2182 (13.5%) | 281 (14.6%) | 0.03 | 1505 (13.0%) | 411 (13.8%) | 0.02 | 1345 (13.2%) | 732 (14.3%) | 0.03 |
| 4 (2.7–3.0) | 5747 (23.0%) | 225 (19.8%) | 0.08 | 3269 (20.3%) | 359 (18.6%) | 0.04 | 2308 (19.9%) | 561 (18.9%) | 0.03 | 1822 (17.9%) | 1084 (21.2%) | 0.08 |
| 5 (3.1–5.7) | 5824 (23.3%) | 233 (20.5%) | 0.07 | 3203 (19.8%) | 382 (19.8%) | 0.00 | 1844 (15.9%) | 595 (20.0%) | 0.11 | 1303 (12.8%) | 962 (18.8%) | 0.16 |
| Missing | 213 (0.9%) | 12 (1.1%) | 0.02 | 156 (1.0%) | 19 (1.0%) | 0.00 | 64 (0.6%) | 26 (0.9%) | 0.04 | 72 (0.7%) | 25 (0.5%) | 0.03 |
| Self-identified visible minority quintile | ||||||||||||
| 1 (0.0%–2.2%) | 5864 (23.5%) | 247 (21.7%) | 0.04 | 4054 (25.1%) | 392 (20.4%) | 0.11 | 2811 (24.3%) | 605 (20.3%) | 0.09 | 2126 (20.9%) | 865 (16.9%) | 0.10 |
| 2 (2.2%–7.5%) | 5445 (21.8%) | 181 (15.9%) | 0.15 | 3624 (22.5%) | 345 (17.9%) | 0.11 | 2675 (23.1%) | 548 (18.4%) | 0.12 | 2305 (22.7%) | 902 (17.6%) | 0.13 |
| 3 (7.5%–18.7%) | 4387 (17.5%) | 192 (16.9%) | 0.02 | 2771 (17.2%) | 356 (18.5%) | 0.03 | 2039 (17.6%) | 514 (17.3%) | 0.01 | 2150 (21.2%) | 955 (18.6%) | 0.06 |
| 4 (18.7%–43.5%) | 4174 (16.7%) | 231 (20.3%) | 0.09 | 2488 (15.4%) | 347 (18.0%) | 0.07 | 1963 (16.9%) | 555 (18.7%) | 0.04 | 1894 (18.7%) | 1069 (20.9%) | 0.06 |
| 5 (43.5%–100%) | 4921 (19.7%) | 273 (24.0%) | 0.11 | 3061 (19.0%) | 470 (24.4%) | 0.13 | 2031 (17.5%) | 731 (24.6%) | 0.17 | 1618 (15.9%) | 1311 (25.6%) | 0.24 |
| Missing | 211 (0.8%) | 12 (1.1%) | 0.02 | 141 (0.9%) | 16 (0.8%) | 0.00 | 66 (0.6%) | 22 (0.7%) | 0.02 | 61 (0.6%) | 21 (0.4%) | 0.03 |
| Receipt of 2019–2020 and/or 2020–2021 influenza vaccination | 8842 (35.4%) | 311 (27.4%) | 0.17 | 8064 (50.0%) | 777 (40.3%) | 0.19 | 8094 (69.9%) | 1594 (53.6%) | 0.34 | 7573 (74.6%) | 3249 (63.4%) | 0.24 |
| Prior positive SARS-CoV-2 test | 1674 (6.7%) | 29 (2.6%) | 0.20 | 789 (4.9%) | 21 (1.1%) | 0.22 | 345 (3.0%) | 35 (1.2%) | 0.13 | 248 (2.4%) | 43 (0.8%) | 0.13 |
| Number of SARS-CoV-2 tests within 3 months prior to December 14, 2020 | ||||||||||||
| 0 | 15,958 (63.8%) | 957 (84.2%) | 0.48 | 11,629 (72.1%) | 1660 (86.2%) | 0.35 | 9622 (83.1%) | 2662 (89.5%) | 0.19 | 8676 (85.4%) | 4596 (89.7%) | 0.13 |
| 1 | 4364 (17.5%) | 117 (10.3%) | 0.21 | 2337 (14.5%) | 187 (9.7%) | 0.15 | 1341 (11.6%) | 225 (7.6%) | 0.14 | 953 (9.4%) | 361 (7.0%) | 0.09 |
| ≥2 | 4680 (18.7%) | 62 (5.5%) | 0.42 | 2173 (13.5%) | 79 (4.1%) | 0.34 | 622 (5.4%) | 88 (3.0%) | 0.12 | 525 (5.2%) | 166 (3.2%) | 0.10 |
| Any comorbidity | 14,709 (58.8%) | 893 (78.6%) | 0.44 | 12,236 (75.8%) | 1665 (86.4%) | 0.27 | 10,362 (89.4%) | 2791 (93.8%) | 0.16 | 9826 (96.8%) | 4995 (97.5%) | 0.04 |
| Receipt of home care services | ||||||||||||
| None | 24,611 (98.4%) | 1058 (93.1%) | 0.27 | 15,486 (96.0%) | 1791 (93.0%) | 0.13 | 10,683 (92.2%) | 2726 (91.6%) | 0.02 | 8861 (87.3%) | 4537 (88.6%) | 0.04 |
| Short stay | 279 (1.1%) | 41 (3.6%) | 0.16 | 402 (2.5%) | 64 (3.3%) | 0.05 | 459 (4.0%) | 104 (3.5%) | 0.02 | 512 (5.0%) | 162 (3.2%) | 0.09 |
| Long stay | 96 (0.4%) | 32–36 (2.8–3.2%) | 0.20 | 217 (1.3%) | 60 (3.1%) | 0.12 | 394 (3.4%) | 135 (4.5%) | 0.06 | 734 (7.2%) | 401 (7.8%) | 0.02 |
| Palliative | 16 (0.1%) | ≤5 (≤0.4%) | 0.05 | 34 (0.2%) | 11 (0.6%) | 0.06 | 49 (0.4%) | 10 (0.3%) | 0.01 | 47 (0.5%) | 23 (0.4%) | 0.00 |
| Unvaccinatedc | 944 (3.8%) | 416 (36.6%) | 0.90 | 840 (5.2%) | 695 (36.1%) | 0.83 | 572 (4.9%) | 880 (29.6%) | 0.69 | 538 (5.3%) | 1136 (22.2%) | 0.51 |
| Time since second dosec | ||||||||||||
| 7–59 days | 119 (0.5%) | 10 (0.9%) | 0.05 | 60 (0.4%) | 10 (0.5%) | 0.02 | 25 (0.2%) | 6 (0.2%) | 0.00 | 27 (0.3%) | 10 (0.2%) | 0.01 |
| 60–119 days | 396 (1.6%) | 37 (3.3%) | 0.11 | 149 (0.9%) | 27 (1.4%) | 0.04 | 82 (0.7%) | 27 (0.9%) | 0.02 | 32 (0.3%) | 34 (0.7%) | 0.05 |
| 120–179 days | 1066 (4.3%) | 65 (5.7%) | 0.07 | 544 (3.4%) | 107 (5.6%) | 0.11 | 205 (1.8%) | 112 (3.8%) | 0.12 | 135 (1.3%) | 125 (2.4%) | 0.08 |
| 180–239 days | 2246 (9.0%) | 136 (12.0%) | 0.10 | 1,230 (7.6%) | 206 (10.7%) | 0.11 | 538 (4.6%) | 332 (11.2%) | 0.24 | 423 (4.2%) | 542 (10.6%) | 0.25 |
| 240–299 days | 848 (3.4%) | 55 (4.8%) | 0.07 | 524 (3.2%) | 108 (5.6%) | 0.11 | 357 (3.1%) | 133 (4.5%) | 0.07 | 290 (2.9%) | 180 (3.5%) | 0.04 |
| ≥300 days | 1,215 (4.9%) | 86 (7.6%) | 0.11 | 778 (4.8%) | 139 (7.2%) | 0.10 | 447 (3.9%) | 163 (5.5%) | 0.08 | 471 (4.6%) | 363 (7.1%) | 0.10 |
| Time since third dosec | ||||||||||||
| 0–6 days | 402 (1.6%) | 8 (0.7%) | 0.08 | 233 (1.4%) | 14 (0.7%) | 0.07 | 109 (0.9%) | 30 (1.0%) | 0.01 | 65 (0.6%) | 49 (1.0%) | 0.04 |
| 7–59 days | 5681 (22.7%) | 68 (6.0%) | 0.49 | 3650 (22.6%) | 94 (4.9%) | 0.53 | 2101 (18.1%) | 182 (6.1%) | 0.37 | 1496 (14.7%) | 299 (5.8%) | 0.30 |
| 60–119 days | 4830 (19.3%) | 80 (7.0%) | 0.37 | 2892 (17.9%) | 145 (7.5%) | 0.32 | 1994 (17.2%) | 243 (8.2%) | 0.27 | 1902 (18.7%) | 503 (9.8%) | 0.26 |
| 120–179 days | 3583 (14.3%) | 50 (4.4%) | 0.35 | 2104 (13.0%) | 117 (6.1%) | 0.24 | 1699 (14.7%) | 246 (8.3%) | 0.20 | 1400 (13.8%) | 509 (9.9%) | 0.12 |
| 180–239 days | 2086 (8.3%) | 73 (6.4%) | 0.07 | 1116 (6.9%) | 128 (6.6%) | 0.01 | 816 (7.0%) | 226 (7.6%) | 0.02 | 685 (6.7%) | 448 (8.7%) | 0.07 |
| ≥240 days | 1040 (4.2%) | 40 (3.5%) | 0.03 | 479 (3.0%) | 46 (2.4%) | 0.04 | 343 (3.0%) | 109 (3.7%) | 0.04 | 324 (3.2%) | 252 (4.9%) | 0.09 |
| Time since fourth dosec | ||||||||||||
| 0–6 days | 32 (0.1%) | ≤5 (≤0.4%)d | 0.01 | 95 (0.6%) | ≤5 (≤0.3%)d | 0.08 | 103 (0.9%) | 10 (0.3%) | 0.07 | 83 (0.8%) | 29 (0.6%) | 0.03 |
| 7–59 days | 357 (1.4%) | ≤5 (≤0.4%)d | 0.11 | 730 (4.5%) | 28 (1.5%) | 0.18 | 979 (8.5%) | 85 (2.9%) | 0.24 | 905 (8.9%) | 152 (3.0%) | 0.25 |
| 60–119 days | 119 (0.5%) | ≤5 (≤0.4%)d | 0.03 | 511 (3.2%) | 40 (2.1%) | 0.07 | 837 (7.2%) | 106 (3.6%) | 0.16 | 835 (8.2%) | 255 (5.0%) | 0.13 |
| ≥120 days | 38 (0.2%) | ≤5 (≤0.4%)d | 0.02 | 204 (1.3%) | 17-21 (0.9–1.1%)d | 0.02 | 378 (3.3%) | 85 (2.9%) | 0.02 | 543 (5.3%) | 237 (4.6%) | 0.03 |
*Note, not unique by person; individuals may be included more than once.
aProportion reported, unless stated otherwise.
bSD = standardized difference. Standardized differences of >0.10 are considered clinically relevant. Comparing Omicron cases to test-negative controls.
cSum of all rows (unvaccinated and vaccinated) equals 100%.
dDue to institutional privacy policies, any cells ≤5 (except for missing values) must be suppressed and ranges must be provided for complementary cells to prevent back calculation.