Table. Characteristics of Children Younger Than 5 Years Hospitalized for RSV-Related Illness in Ontario, 2017-2018 Through 2022-2023a.
| Characteristic | RSV seasonb | ||||
|---|---|---|---|---|---|
| 2017-2018 | 2018-2019 | 2019-2020 | 2021-2022 | 2022-2023 | |
| Population size | 713 547 | 712 233 | 708 633 | 682 201 | 646 401 |
| No. hospitalized | 2008 | 2383 | 2421 | 1972 | 4977 |
| Overall admission rate, per 100 000 children | 281.4 | 334.6 | 341.6 | 289.1 | 770.0 |
| Age at time of admission, No. (%), mo | |||||
| <1 | 547 (27.2) | 657 (27.6) | 561 (23.2) | 585 (29.7) | 958 (19.2) |
| 2-3 | 303 (15.1) | 393 (16.5) | 372 (15.4) | 288 (14.6) | 635 (12.8) |
| 4-5 | 199 (9.9) | 198 (8.3) | 211 (8.7) | 141 (7.2) | 367 (7.4) |
| 6-11 | 315 (15.7) | 321 (13.5) | 319 (13.2) | 195 (9.9) | 609 (12.2) |
| 12-23 | 368 (18.3) | 446 (18.7) | 534 (22.1) | 337 (17.1) | 1028 (20.7) |
| 24-35 | 148 (7.4) | 203 (8.5) | 219 (9.0) | 231 (11.7) | 620 (12.5) |
| 36-59 | 128 (6.4) | 165 (6.9) | 205 (8.5) | 195 (9.9) | 760 (15.3) |
| Mean (SD) | 10.81 (12.64) | 11.26 (12.88) | 12.56 (13.32) | 12.85 (14.29) | 16.08 (15.46) |
| Median (IQR) | 5 (2-16) | 5 (2-17) | 7 (2-19) | 5 (2-22) | 11 (3-26) |
| Male sex, No. (%) | 1118 (55.7) | 1287 (54.0) | 1338 (55.3) | 1096 (55.6) | 2755 (55.4) |
| Rural residence, No. (%) | 209 (10.4) | 283 (11.9) | 250 (10.3) | 262 (13.3) | 594 (11.9) |
| Neighborhood income quintile, No. (%) | |||||
| 1 (Lowest income) | 455 (22.7) | 551 (23.1) | 540 (22.3) | 392 (19.9) | 1068 (21.5) |
| 2 | 422 (21.0) | 462 (19.4) | 429 (17.7) | 346 (17.5) | 909 (18.3) |
| 3 | 395 (19.7) | 484 (20.3) | 510 (21.1) | 380 (19.3) | 1022 (20.5) |
| 4 | 369 (18.4) | 500 (21.0) | 478 (19.7) | 451 (22.9) | 1001 (20.1) |
| 5 (Highest income) | 352 (17.5) | 359 (15.1) | 427 (17.6) | 352 (17.8) | 824 (16.6) |
| Unknown | 15 (0.7) | 27 (1.1) | 37 (1.5) | 51 (2.6) | 153 (3.1) |
| Material resources quintile, No. (%) | |||||
| 1 (Least marginalized) | 361 (18.0) | 447 (18.8) | 478 (19.7) | 379 (19.2) | 924 (18.6) |
| 2 | 367 (18.3) | 456 (19.1) | 479 (19.8) | 417 (21.1) | 945 (19.0) |
| 3 | 370 (18.4) | 425 (17.8) | 434 (17.9) | 345 (17.5) | 943 (18.9) |
| 4 | 373 (18.6) | 444 (18.6) | 390 (16.1) | 343 (17.4) | 895 (18.0) |
| 5 (Most marginalized) | 498 (24.8) | 553 (23.2) | 568 (23.5) | 421 (21.3) | 1031 (20.7) |
| Unknown | 39 (1.9) | 58 (2.4) | 72 (3.0) | 67 (3.4) | 239 (4.8) |
| Any comorbidities at birth, No. (%) | |||||
| Major congenital anomaly | 222 (11.1) | 247 (10.4) | 236 (9.7) | 212 (10.8) | 439 (8.8) |
| Congenital heart disease | 7 (0.3) | 19 (0.8) | 18 (0.7) | 12 (0.6) | 25 (0.5) |
| Chronic lung disease | 92 (4.6) | 102 (4.3) | 99 (4.1) | 99 (5.0) | 159 (3.2) |
| Trisomy 21 | 19 (0.9) | 14 (0.6) | 26 (1.1) | 13 (0.7) | 35 (0.7) |
| Any chronic medical condition, No. (%) | 340 (16.9) | 406 (17.0) | 431 (17.8) | 346 (17.5) | 796 (16.0) |
| Born preterm (<37 wk), No. (%) | 293 (14.6) | 404 (17.0) | 374 (15.4) | 312 (15.8) | 746 (15.0) |
| Palivizumab eligibility, No. (%) | |||||
| Clearly eligible | 66 (3.3) | 88 (3.7) | 56 (2.3) | 57 (2.9) | 106 (2.1) |
| Possibly eligible | 75 (3.7) | 66 (2.8) | 57 (2.4) | 65 (3.3) | 111 (2.2) |
| Ineligible | 1867 (93.0) | 2229 (93.5) | 2308 (95.3) | 1850 (93.8) | 4760 (95.6) |
| Hospitalization outcomes | |||||
| Length of stay, mean (SD), d | 3.75 (5.12) | 4.08 (9.64) | 3.78 (6.00) | 3.96 (9.25) | 4.16 (5.47) |
| ICU admission, No. (%) | 197 (9.8) | 261 (11.0) | 233 (9.6) | 224 (11.4) | 691 (13.9) |
| ICU length of stay, mean (SD), d | 1.14 (0.51) | 1.17 (0.46) | 1.23 (0.58) | 1.26 (0.85) | 1.15 (0.50) |
| Overall ICU admission rate, per 100 000 children (population-based) | 27.61 | 36.65 | 32.88 | 32.83 | 106.90 |
| Mechanical ventilation use, No. (%) | 85 (4.2) | 104 (4.4) | 101 (4.2) | 65 (3.3) | 235 (4.7) |
| Time requiring mechanical ventilation, mean (SD), d | 1.29 (0.61) | 1.27 (0.84) | 1.37 (0.80) | 1.25 (0.50) | 1.23 (0.53) |
| Overall mechanical ventilation rate, per 100 000 children (population-based) | 11.91 | 14.60 | 14.25 | 9.53 | 36.36 |
| Required ECMO, No. (%)c | 0 | <6 | 0 | 0 | <6 |
| In-hospital death, No. (%)c | 0 | <6 | <6 | <6 | <6 |
Abbreviations: ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; RSV, respiratory syncytial virus.
a
Eleven RSV hospitalizations and 7 ICU admissions occurred during the 2020-2021 season; data not shown given small cell sizes.
b
RSV season defined as July 1 through June 30 of the subsequent year.
c
Cell sizes less than 6 have been suppressed.