Pre-existing High-Risk Conditions in Case-Patients and Controls (Percentage of Case-Patients or Control Subjects With Specific Condition of All Case-Patients or Control Subjects With Any High-Risk Condition)
| Condition | Number of Case-Patients (%) | Number of Control Subjects (%) |
|---|---|---|
| Prematurity (≤36 weeks’ gestational age) | ||
| Required mechanical ventilation | 2 (6) | 0 (0) |
| Required O2 but not mechanical ventilation | 5 (16) | 3 (38) |
| No O2 or mechanical ventilation | 14 (44) | 4 (50) |
| 21 (66) | 7 (88) | |
| Lung disease | ||
| Congenital lung disease (eg, diaphragmatic hernia, pulmonary hypoplasia) requiring surgery or treatment | 3 (9) | 0 (0) |
| Previous mechanical ventilation (other than for prematurity) | 1 (3) | 0 (0) |
| 4 (12) | 0 (0) | |
| Significant congenital or acquired heart condition | 6 (19) | 1 (12) |
| Other systemic conditions* | 4 (12) | 0 (0) |
| Overall total | 32 | 8 |
↵* Other conditions include children with Down syndrome, traumatic encephalopathy, congenital hypothyroidism, and low birth weight at full-term infant.
** Subtotals may add to more than total as 1 infant may be classified in >1 major disease category.