Table 2.
Demographics of Enrolled Infants, by Case Status
| Cases (%) n=251 | Controls (%) n=682 | p-value | |
|---|---|---|---|
| Sex, male | 123 (49.0) | 330 (48.4) | .87 |
| Racea | |||
| White | 199 (80.9) | 543 (81.9) | .62 |
| Black | 22 (8.9) | 47 (7.1) | |
| Other | 25 (10.2) | 73 (11.0) | |
| Hispanic Ethnicity | 156 (62.2) | 344 (50.4) | .002 |
| Age in weeksb | |||
| 0–1 weeks | 11 (4.4) | 147 (21.6) | <.0001 |
| 2–3 weeks | 66 (26.3) | 147 (21.6) | |
| 4–5 weeks | 70 (27.9) | 153 (22.4) | |
| 6–7 weeks | 79 (31.5) | 178 (26.1) | |
| 8 weeks | 25 (9.9) | 57 (8.3) | |
| Infants with a DTaP dose | 2 (0.8) | 3 (0.4) | .62 |
a
Calculated from those with known race (n=246 for case-infants; n=663 for control-infants)
b
Age at date of cough onset (for case-infants) or date of cough onset of matched case-infant (for control-infants)