Characteristics of Children Hospitalized With Acute Respiratory Illness Overall and by Influenza Positivity and Influenza Vaccination Status (Documentation Supplemented by Parental Report), NVSN, 2018–2019
| Characteristic | No. Enrolled, n (%) | Influenza-Positive, n (%) | Influenza-Negative, n (%) | P | Vaccinated (≥1 Dose), n (%) | Not Vaccinated, n (%) | P |
|---|---|---|---|---|---|---|---|
| Overall | 1792 | 226 | 1566 | 1070 | 722 | ||
| Sex | .98 | .69 | |||||
| Male | 998 (56) | 126 (56) | 872 (56) | 600 (56) | 398 (55) | ||
| Female | 794 (44) | 100 (44) | 694 (44) | 470 (44) | 324 (45) | ||
| Age category | <.001 | <.001 | |||||
| 6 mo to <5 y | 1255 (70) | 109 (48) | 1146 (73) | 784 (73) | 471 (65) | ||
| 5–17 y | 537 (30) | 117 (52) | 420 (27) | 286 (27) | 251 (35) | ||
| Race and/or ethnicity | .004 | <.001 | |||||
| White, non-Hispanic | 696 (39) | 104 (46) | 592 (38) | 429 (40) | 267 (37) | ||
| Black, non-Hispanic | 423 (24) | 61 (27) | 362 (23) | 200 (19) | 223 (31) | ||
| Other, non-Hispanic | 177 (10) | 20 (9) | 157 (10) | 103 (10) | 74 (10) | ||
| Hispanic | 496 (28) | 41 (18) | 455 (29) | 338 (32) | 158 (22) | ||
| Underlying medical conditionsa | .32 | .01 | |||||
| ≥1 | 1031 (58) | 137 (61) | 894 (57) | 642 (60) | 389 (54) | ||
| None | 761 (42) | 89 (39) | 672 (43) | 428 (40) | 333 (46) | ||
| Hospitalization in past year | .27 | <.001 | |||||
| 0 | 1093 (61) | 144 (64) | 949 (61) | 609 (57) | 484 (67) | ||
| ≥1 | 685 (38) | 82 (36) | 603 (39) | 451 (42) | 234 (32) | ||
| Unknown | 14 (1) | 0 (0) | 14 (1) | 10 (1) | 4 (1) | ||
| Surveillance site | <.001 | <.001 | |||||
| Cincinnati | 133 (7) | 22 (10) | 111 (7) | 65 (6) | 68 (9) | ||
| Houston | 471 (26) | 45 (20) | 426 (27) | 341 (32) | 130 (18) | ||
| Kansas City | 137 (8) | 7 (3) | 130 (8) | 59 (6) | 78 (11) | ||
| Nashville | 275 (15) | 24 (11) | 251 (16) | 136 (13) | 139 (19) | ||
| Pittsburgh | 448 (25) | 84 (37) | 364 (23) | 247 (23) | 201 (28) | ||
| Rochester | 113 (6) | 14 (6) | 99 (6) | 69 (6) | 44 (6) | ||
| Seattle | 215 (12) | 30 (13) | 185 (12) | 153 (14) | 62 (9) | ||
| Insurance status | .45 | <.001 | |||||
| Public (or none or self-pay) | 1169 (65) | 148 (65) | 1021 (65) | 660 (62) | 509 (70) | ||
| Private or both | 605 (34) | 74 (33) | 531 (34) | 403 (38) | 202 (28) | ||
| Unknown | 18 (1) | 4 (2) | 14 (1) | 7 (1) | 11 (2) | ||
| Days of symptoms since illness onset | .73 | .07 | |||||
| 0–2 | 717 (40) | 96 (42) | 621 (40) | 430 (40) | 287 (40) | ||
| 3–4 | 561 (31) | 64 (28) | 497 (32) | 353 (33) | 208 (29) | ||
| 5–7 | 384 (21) | 48 (21) | 336 (21) | 220 (21) | 164 (23) | ||
| 8–10 | 130 (7) | 18 (8) | 112 (7) | 67 (6) | 63 (9) | ||
| Received mechanical ventilation | 88 (5) | 12 (5) | 76 (5) | .94 | 51 (5) | 37 (5) | .62 |
| Death | 7 (<1) | 1 (<1) | 6 (<1) | 5 (<1) | 2 (<1) |
↵a Comorbid conditions obtained from medical chart review included chronic pulmonary and/or airway, cardiac, gastrointestinal, kidney, endocrine, neurologic and/or neuromuscular, developmental, hematologic and oncologic, genetic and/or metabolic, and immunocompromised conditions; pregnancy; and prematurity.