TABLE 2.
RISK FACTORS FOR ASTHMA AT AGE 6 YEARS
| Univariate
|
Multivariate
|
Multivariate (Stepwise)
|
|||||
|---|---|---|---|---|---|---|---|
| Risk Factors | With Risk Factor, n (%) | OR (95% CI) | P Value | OR (95% CI) | P Value | OR (95% CI) | P Value |
| Maternal asthma | 106/249 (43) | 1.3 (0.7, 2.3) | 0.36 | 1.7 (0.9, 3.5) | 0.12 | ||
| Paternal asthma | 74/242 (31) | 1.2 (0.7, 2.2) | 0.57 | 1.0 (0.5, 2.3) | 0.95 | ||
| Birth month | — | — | 0.42 | — | 0.38 | ||
| Birth weight, lb | — | 1.1 (0.8, 1.3) | 0.67 | 0.9 (0.7, 1.3) | 0.64 | ||
| Cat in household at birth | 76/259 (29) | 1.0 (0.5, 1.7) | 0.90 | 0.9 (0.4, 2.0) | 0.86 | ||
| Dog in household at birth | 92/259 (36) | 0.5 (0.3, 0.9) | 0.02 | 0.6 (0.3, 1.2) | 0.16 | 0.6 (0.3, 1.1) | 0.08 |
| Older siblings | 145/259 (56) | 1.8 (1.0, 3.1) | 0.05 | 1.5 (0.7, 3.1) | 0.27 | 1.9 (1.0, 3.5) | 0.03 |
| Passive smoke exposure (1st yr) | 64/259 (25) | 1.1 (0.6, 2.1) | 0.76 | 0.7 (0.3, 1.5) | 0.33 | ||
| Daycare (1st yr) | 123/259 (47) | 0.7 (0.4, 1.2) | 0.20 | 0.6 (0.3, 1.4) | 0.24 | ||
| Exclusive breastfeeding (1st 6 mo) | 84/259 (32) | 1.1 (0.6, 2.0) | 0.70 | 0.9 (0.4, 1.9) | 0.73 | ||
| Atopic dermatitis (1st yr) | 65/253 (26) | 1.7 (0.9, 3.1) | 0.08 | 1.2 (0.5, 2.5) | 0.70 | ||
| Aeroallergen sensitization (1st yr) | 34/255 (13) | 3.6 (1.7, 7.5) | 0.0008 | 4.3 (1.4, 13.0) | 0.01 | 2.7 (1.2, 6.2) | 0.02 |
| Food sensitization (1st yr) | 65/255 (25) | 2.8 (1.6, 5.2) | 0.0006 | 1.7 (0.7, 3.9) | 0.23 | 2.0 (1.0, 3.9) | 0.04 |
Definition of abbreviations: CI = confidence interval; OR = odds ratio.
Risk factors included in the multivariate (stepwise) model were chosen using backward elimination based on Akaike's information criterion. Values in boldface are statistically significant (P < 0.05).