Table 3.
Factors associated with immune system development, number of atopic conditions, and childhood rhabdomyosarcoma
| Controls, n (%) |
Cases, n (%) |
ORa | 95% CI | |
|---|---|---|---|---|
| Birth order | ||||
| 1 | 138 (43.3) | 138 (43.4) | 1.00 | Ref. |
| 2 | 101 (31.6) | 102 (32.1) | 0.95 | 0.64–1.39 |
| ≥3 | 80 (25.1) | 78 (24.5) | 0.86 | 0.55–1.33 |
| p for trend = 0.50 | ||||
| Day-care attendance | ||||
| No | 145 (45.0) | 191 (59.3) | 1.00 | Ref. |
| Yes | 177 (55.0) | 131 (40.7) | 0.48 | 0.32–0.71 |
| Breastfeeding | ||||
| No | 142 (44.8) | 156 (48.9) | 1.00 | Ref. |
| Yes | 175 (55.2) | 163 (51.1) | 0.79 | 0.54–1.14 |
| Breastfeeding duration, months | ||||
| 0 | 143 (45.1) | 163 (50.9) | 1.00 | Ref. |
| <6 | 78 (24.6) | 82 (25.6) | 0.82 | 0.54–1.25 |
| 6–12 | 52 (16.4) | 54 (16.9) | 0.78 | 0.47–1.31 |
| ≥12 | 44 (13.9) | 21 (6.6) | 0.36 | 0.18–0.70 |
| p for trend = 0.01 | ||||
| Number of atopic conditions | ||||
| 0 | 32 (9.9) | 52 (16.1) | 1.00 | Ref. |
| 1 | 70 (21.8) | 104 (32.3) | 0.70 | 0.39–1.26 |
| 2 | 67 (20.8) | 83 (25.8) | 0.51 | 0.27–0.96 |
| ≥3 | 153 (47.5) | 83 (25.8) | 0.22 | 0.11–0.43 |
| p for trend < 0.001 |
a
Adjusted for age, race, sex, household income, maternal, and paternal education