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

From: Effectiveness of mRNA COVID-19 vaccine booster doses against Omicron severe outcomes

 

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

  1. *Note, not unique by person; individuals may be included more than once.
  2. aProportion reported, unless stated otherwise.
  3. bSD = standardized difference. Standardized differences of >0.10 are considered clinically relevant. Comparing Omicron cases to test-negative controls.
  4. cSum of all rows (unvaccinated and vaccinated) equals 100%.
  5. 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.
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