TABLE 1.
Baseline characteristics for all children hospitalized with RSV infection and influenza overall and by age categories.
| RSV | Influenza | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Total | Age < 6 months | Age 6–11 months | Age 1 < 2 years | Age 2 < 5 years | Total | Age < 6 months | Age 6–11 months | Age 1 < 2 years | Age 2 < 5 years | |
| Total number of patients, n (relative % by age group) | 90,413 (100) | 35,273 (39.0) | 18,827 (20.8) | 23,898 (26.4) | 12,415 (13.7) | 11,186 (100) | 2141 (19.1) | 1188 (10.6) | 2845 (25.4) | 5012 (44.8) |
| Sex, n (%) | ||||||||||
| Female | 40,958 (45.3) | 15,564 (44.1) | 8030 (42.7) | 11,133 (46.6) | 6231 (50.2) | 4890 (43.7) | 986 (46.1) | 517 (43.5) | 1282 (45.1) | 2105 (42.0) |
| Male | 49,455 (54.7) | 19,709 (55.9) | 10,797 (57.4) | 12,765 (53.4) | 6184 (49.8) | 6296 (56.3) | 1155 (54.0) | 671 (56.5) | 1563 (54.9) | 2907 (58.0) |
| Age, months | ||||||||||
| Mean (SD) | (11.8, 11.1) | (2.5, 1.4) | (8.4, 1.7) | (16.7, 3.4) | (33.9, 8.7) | (24.0, 17.4) | (2.6, 1.3) | (8.6, 1.7) | (17.4, 3.3) | (40.7, 10.6) |
| Median (IQR) | 9.0 (3.0–17.0) | 2.0 (1.0–4.0) | 8.0 (7.0–10.0) | 16.0 (14.0–19.0) | 32.0 (27.0–40.0) | 21.0 (9.0–38.0) | 2.0 (2.0–3.0) | 9.0 (7.0–10.0) | 17.0 (14.0–20.0) | 40.0 (31.0–50.0) |
| Season by year, n (%) | ||||||||||
| 2011 (May 2011 to April 2012) | 2000 (2.2) | 724 (2.1) | 451 (2.4) | 547 (2.3) | 278 (2.2) | 360 (3.2) | 70 (3.3) | 38 (3.2) | 79 (2.8) | 173 (3.5) |
| 2012 (May 2012 to April 2013) | 3609 (4.0) | 1367 (3.9) | 845 (4.5) | 940 (3.9) | 457 (3.7) | 517 (4.6) | 99 (4.6) | 44 (3.7) | 129 (4.5) | 245 (4.9) |
| 2013 (May 2013 to April 2014) | 5259 (5.8) | 2252 (6.4) | 1191 (6.3) | 1227 (5.1) | 589 (4.8) | 933 (8.4) | 147 (6.9) | 99 (8.4) | 223 (7.9) | 464 (9.3) |
| 2014 (May 2014 to April 2015) | 8057 (8.9) | 3223 (9.1) | 1793 (9.5) | 2038 (8.5) | 1003 (8.1) | 1142 (10.2) | 262 (12.3) | 117 (9.9) | 275 (9.7) | 488 (9.8) |
| 2015 (May 2015 to April 2016) | 9532 (10.6) | 3834 (10.9) | 2057 (10.9) | 2464 (10.3) | 1177 (9.5) | 1575 (14.1) | 231 (10.8) | 202 (17.1) | 403 (14.2) | 739 (14.8) |
| 2016 (May 2016 to April 2017) | 8926 (9.9) | 3626 (10.3) | 2057 (10.9) | 2302 (9.6) | 941 (7.6) | 1378 (12.4) | 302 (14.1) | 128 (10.8) | 348 (12.3) | 600 (12.0) |
| 2017 (May 2017 to April 2018) | 13,434 (14.9) | 5148 (14.6) | 2987 (15.9) | 3588 (15.0) | 1711 (13.8) | 1677 (15.0) | 303 (14.2) | 174 (14.7) | 396 (13.9) | 804 (16.1) |
| 2018 (May 2018 to April 2019) | 12,356 (13.7) | 5105 (14.5) | 2754 (14.6) | 3148 (13.2) | 1349 (10.9) | 1895 (17.0) | 423 (19.8) | 186 (15.7) | 490 (17.3) | 796 (16.0) |
| 2019 (May 2019 to April 2020) | 11,576 (12.8) | 4380 (12.4) | 2382 (12.7) | 3313 (13.9) | 1501 (12.1) | 1660 (14.9) | 296 (13.9) | 194 (16.4) | 491 (17.3) | 679 (13.6) |
| 2020 (May to December) | 802 (0.9) | 304 (0.9) | 166 (0.9) | 238 (1.0) | 94 (0.8) | 3 (0.0) | 1 (0.1) | 2 (0.2) | 0 (0.0) | 0 (0.0) |
| 2021 (January to December) | 12,396 (13.7) | 4456 (12.6) | 1771 (9.4) | 3438 (14.4) | 2731 (22.0) | 6 (0.1) | 1 (0.1) | 1 (0.1) | 3 (0.1) | 1 (0.0) |
| 2022 (January to July) | 2410 (2.7) | 832 (2.4) | 362 (1.9) | 638 (2.7) | 578 (4.7) | 4 (0.0) | 1 (0.1) | 0 (0.0) | 3 (0.1) | 0 (0.0) |
| Co‐morbidity during baseline period, n (%) | ||||||||||
| Down syndrome | 387 (0.4) | 123 (0.4) | 91 (0.5) | 74 (0.3) | 99 (0.8) | 20 (0.2) | 3 (0.1) | 4 (0.3) | 2 (0.1) | 11 (0.2) |
| Congenital heart disease | 1817 (2.0) | 902 (2.6) | 501 (2.7) | 264 (1.1) | 150 (1.2) | 119 (1.1) | 36 (1.7) | 33 (2.8) | 29 (1.0) | 21 (0.4) |
| Bronchopulmonary dysplasia | 110 (0.1) | 40 (0.1) | 42 (0.2) | 18 (0.1) | 10 (0.1) | 5 (0.0) | 1 (0.1) | 2 (0.2) | 1 (0.0) | 1 (0.0) |
| Prematurity | 1979 (2.2) | 1288 (3.7) | 546 (2.9) | 122 (0.5) | 23 (0.2) | 79 (0.7) | 35 (1.6) | 36 (3.0) | 6 (0.2) | 2 (0.0) |
| Immunodeficiency | 169 (0.2) | 68 (0.2) | 45 (0.2) | 35 (0.2) | 21 (0.2) | 29 (0.3) | 4 (0.2) | 6 (0.5) | 5 (0.2) | 14 (0.3) |
| Pulmonary hypoplasia | 19 (0.0) | 10 (0.0) | 4 (0.0) | 2 (0.0) | 3 (0.0) | 2 (0.0) | 1 (0.1) | 1 (0.1) | 0 (0.0) | 0 (0.0) |
| Airway stenosis | 36 (0.0) | 9 (0.0) | 9 (0.1) | 13 (0.1) | 5 (0.0) | 2 (0.0) | 0 (0.0) | 0 (0.0) | 2 (0.1) | 0 (0.0) |
| Esophageal atresia | 3 (0.0) | 1 (0.0) | 0 (0.0) | 2 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| Congenital metabolic disorder | 378 (0.4) | 82 (0.2) | 100 (0.5) | 115 (0.5) | 81 (0.7) | 93 (0.8) | 3 (0.1) | 9 (0.8) | 32 (1.1) | 49 (1.0) |
| Neuromuscular disorder | 358 (0.4) | 68 (0.2) | 77 (0.4) | 106 (0.4) | 107 (0.9) | 100 (0.9) | 1 (0.1) | 13 (1.1) | 30 (1.1) | 56 (1.1) |
| Cystic fibrosis | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) | 0 (0.0) |
| No record of these co‐morbidities | 85,896 (95.0) | 32,977 (93.5) | 17,671 (93.9) | 23,251 (97.3) | 11,997 (96.6) | 10,789 (96.5) | 2064 (96.4) | 1100 (92.6) | 2750 (96.7) | 4875 (97.3) |
| Palivizumab use, n (%) | ||||||||||
| Yes | 1559 (1.7) | 706 (2.0) | 453 (2.4) | 354 (1.5) | 46 (0.4) | 82 (0.7) | 16 (0.8) | 28 (2.4) | 33 (1.2) | 5 (0.1) |
| No record of use | 88,854 (98.3) | 34,567 (98.0) | 18,374 (97.6) | 23,544 (98.5) | 12,369 (99.6) | 11,104 (99.3) | 2125 (99.3) | 1160 (97.6) | 2812 (98.8) | 5007 (99.9) |
| Size of healthcare facilities, n (%) | ||||||||||
| Less than 200 beds | 5252 (5.8) | 1781 (5.1) | 1209 (6.4) | 1454 (6.1) | 808 (6.5) | 551 (4.9) | 68 (3.2) | 55 (4.6) | 156 (5.5) | 272 (5.4) |
| 200 to 499 beds | 50,876 (56.3) | 19,056 (54.0) | 11,029 (58.6) | 13,859 (58.0) | 6932 (55.8) | 6090 (54.4) | 1138 (53.2) | 640 (53.9) | 1578 (55.5) | 2734 (54.6) |
| 500 or more beds | 34,285 (37.9) | 14,436 (40.9) | 6589 (35.0) | 8585 (35.9) | 4675 (37.7) | 4545 (40.6) | 935 (43.7) | 493 (41.5) | 1111 (39.1) | 2006 (40.0) |
Note: Rounding may create totals slightly over or below 100% in some cases.