Table 1.
Baseline characteristics
| Demographics | Total, N = 1065 | Children, n = 262 | Adults, n = 803 |
|---|---|---|---|
| Age, years | |||
| Median | 33 | ||
| Range | 0–96 | ||
| ≤18 | 262 (24.6%) | ||
| 19–59 | 614 (57.6%) | ||
| ≥60 | 189 (17.8%) | ||
| Sex | |||
| Male | 439 (41.2%) | 132 (50.4%) | 307 (38.2%) |
| Female | 626 (58.8%) | 130 (49.6%) | 496 (61.8%) |
| Pregnant | 4 | 4 | |
| Ethnicity | |||
| Mixed | 1026 (96.4%) | 252 (96.2%) | 775 (96.5%) |
| White | 33 (3.1%) | 10 (3.8%) | 23 (2.9%) |
| Other | 5 (0.5%) | 5 (0.6%) | |
| Medical history | |||
| Influenza vaccination | 504 (47.3%) | 121 (46.2%) | 383 (47.7%) |
| Asthma | 151 (14.2%) | 16 (6.1%) | 135 (16.8%) |
| CVD | 147 (13.8%) | 17 (6.5%) | 130 (16.2%) |
| Diabetes | 99 (9.3%) | 99 (12.3%) | |
| Immunodeficiency | 48 (4.5%) | 8 (3.1%) | 40 (5.0%) |
| Renal disorder | 42 (3.9%) | 4 (1.5%) | 38 (4.8%) |
| COPD | 36 (3.4%) | 36 (4.5%) | |
| BMI categorya | |||
| Obese | 207 (19.9%) | 23 (9.2%) | 184 (23.3%) |
| Overweight | 313 (30.2%) | 42 (16.1%) | 273 (34.6%) |
| Normal | 417 (40.2%) | 121 (48.6%) | 296 (37.5%) |
| Underweight | 101 (9.7%) | 65 (26.1%) | 36 (4.6%) |
| Median days since symptoms onset | 1 | ||
| Inpatient at baseline | 436 (40.9%) | 113 (43.1%) | 323 (40.2%) |
| Outpatient at baseline | 629 (59.1%) | 149 (56.9%) | 480 (59.8) |
BMI, body mass index; COPD, chronic obstructive pulmonary disease; CVD, cardiovascular disease; SD, standard deviation.
a
BMI categories: underweight = BMI < 18.5 kg/m2 (or <1 SD for children); normal weight = 18.5–24.9 kg/m2; overweight = 25–29.9 kg/m2 (>1SD for children); obese = BMI of ≥30 kg/m2 (>2 SD for children).