Table 1.
Demographic and clinical features of the global study subjects with severe and mild bronchiolitis
| Variable | Patients, No. (%)a (N = 682) | OR (95% CI) | p Value | |
|---|---|---|---|---|
| Severe disease (N = 308) | Mild disease (N = 374) | |||
| Age, mean (IQR), months | 7.9 (0.2–9) | 10.3 (3–16) | <0.001* | |
| Male sex | 180 (58.4) | 216 (57.8) | 1.0 (0.76–1.39) | 0.88 |
| Gestational age, mean (IQR), weeks | 38.6 (38–39) | 38.7 (38–39) | 0.19 | |
| Birth weight, mean (SD), g | 3367.8 (489.2) | 3355.1 (474.4) | 0.71 | |
| Delivery | ||||
| Eutocic | 164 (53.2) | 195 (52.1) | 1 | |
| Cesarean | 136 (44.2) | 171 (45.7) | 0.9 (0.69–1.29) | 0.78 |
| Forceps | 8 (2.6) | 8 (2.1) | 1.2 (0.43–3.23) | 0.92 |
| Maternal pregnancy diseases | ||||
| Preeclampsia | 7 (2.3) | 17 (4.5) | 0.5 (0.2–1.2) | 0.16 |
| Diabetes | 22 (7.1) | 34 (9.1) | 0.8 (0.45–1.4) | 0.53 |
| Hypothyroidism | 8 (2.6) | 9 (2.4) | 1.1 (0.4–2.83) | 0.99 |
| Epilepsy or neurological disease | 2 (0.6) | 2 (0.5) | 1.2 (0.17–8.7) | 0.99 |
| Other diseases | 16 (5.2) | 22 (5.9) | 0.9 (0.45–1.7) | 0.82 |
| Weight at presentation, mean (SD), kg | 7.89 (3.7) | 9.02 (3.5) | <0.001* | |
| Nutritional status | ||||
| Undernutrition | 14 (4.5) | 19 (5.1) | 0.9 (0.42–1.76) | 0.81 |
| Normal | 216 (70.1) | 253 (67.6) | 1 | |
| Overweight | 53 (17.2) | 77 (20.6) | 10.8 (0.54–1.2) | 0.32 |
| Obesity | 25 (8.1) | 25 (6.7) | 1.2 (0.65–2.1) | 0.71 |
| Breastfeeding at 6 months of age | 227 (73.7) | 269 (71.9) | 1.2 (0.82–1.6) | 0.67 |
| Maternal smoking during pregnancy | 60 (19.5) | 73 (19.5) | 1.0 (0.69–1.48) | 0.99 |
| Tobacco exposure at homeb | 177 (57.5) | 159 (42.5) | 1.8 (1.3–2.5) | <0.001* |
| Parental history of asthma | 159 (51.6) | 157 (41.9) | 1.5 (1.1–2.0) | 0.01* |
| Personal history of atopy | 8 (2.6) | 10 (2.7) | 1.0 (0.38–2.52) | 0.99 |
| Treatment for current illness | ||||
| Bronchodilators | 307 (99.7) | 363 (97) | 9.3 (1.2–72.5) | 0.015* |
| Systemic corticosteroids | 200 (64.9) | 145 (38.7) | 2.9 (2.1–4.0) | <0.001* |
| Antibiotics | 190 (61.7) | 101 (27) | 4.4 (3.1–6.0) | <0.001* |
| Viral coinfections | 23 (7.5) | 33 (8.8) | 0.57 | |
| Positive cultures | ||||
| Blood culture | 2 (0.6) | 1 (0.2) | 0.85 | |
| Urine culture | 11 (3.6) | 10 (2.7) | 0.64 | |
| Clinical bacterial coinfection | 141 (45.8) | 59 (15.8) | 4.5 (3.2–6.5) | <0.001* |
| Hospital length of stay, mean (SD), days | 9.14 (5.16) | 3.58 (1.73) | <0.001* | |
| Supplemental oxygen days, mean (SD), days | 8.04 (5) | 2.43 (1.59) | <0.001* | |
| PICU admission | 176 (57.1) | 30 (8) | 15.3 (9.9–23.7) | <0.001* |
| PICU length of stay, mean (SD), daysc | 2.63 (3.79) | 0.05 (0.39) | <0.001* | |
| Days of IVM, mean (SD), daysd | 0.42 (2.07) | 0 (0) | <0.001* | |
| Ventilatory support | ||||
| NIV | 133 (43.2) | 21 (5.6) | <0.001* | |
| IMVe | 25 (8.1) | 0 (0) | ||
| RDAI score, mean (SD) | 8.8 (3.5) | 6.82 (3.5) | <0.001* | |
| TAL score, mean (SD) | 5.2 (1.68) | 4.1 (1.74) | <0.001* | |
| PRESS score, mean (SD) | 3.65 (0.97) | 2.87 (1.34) | <0.001* | |
| PIM-2 score, mean (SD)c | −4.06 (0.99) | −4.28 (0.68) | 0.001* | |
| Mortalityf | 1 (0.3) | 1 (0.26) | 1 | |
IQR interquartile range, SD standard deviation, PICU pediatric intensive care unit, NIV non-invasive mechanical ventilation, IMV invasive mechanical ventilation, RDAI Respiratory Distress Assessment Instrument, PRESS pediatric respiratory severity score, PIM-2 Pediatric Index Mortality 2
*Significant
aData represent no. (%) of patients unless otherwise specified
bAt least one parent smokes
cData for 206 patients admitted to PICU
dData for 25 patients with invasive mechanical ventilation
ep Value not calculated because one or more boxes contains zero
fIncluding 2 died infants with no respiratory reason