Association between variables at birth, socioeconomic factors, and smoking and asthma symptoms (wheeze or waking with breathlessness), BHR, and atopy by polytomous regression analysis (n = 1213)*
| Asthma symptoms in last 12 months OR (95% CI), p value | Atopy or positive BHR OR (95% CI), p value | Two characteristics combined OR (95% CI), p value | |
|---|---|---|---|
| OR, odds ratio; BMI, body mass index; BHR, bronchial hyperresponsiveness. | |||
| *Each assessment was adjusted for all the variables in the table. | |||
| Sex (female) | 1.54 (1.11 to 2.13), 0.009 | 1.33 (0.97 to 1.81), 0.073 | 1.36 (0.95 to 1.95), 0.090 |
| No of siblings | 1.02 (0.95 to 1.09), 0.604 | 0.94 (0.88 to 1.01), 0.108 | 0.96 (0.88 to 1.03), 0.266 |
| Birth weight (100 g) | 0.97 (0.91 to 1.03), 0.307 | 1.01 (0.94 to 1.07), 0.873 | 0.99 (0.92 to 1.07), 0.790 |
| BMI at birth (kg/m2) | 0.98 (0.78 to 1.23), 0.843 | 1.02 (0.82 to 1.28), 0.838 | 0.97 (0.75 to 1.26), 0.814 |
| Smoking status | 2.03 (1.46 to 2.83), <0.001 | 1.18 (0.87 to 1.61), 0.279 | 1.98 (1.37 to 2.87), <0.001 |
| Car ownership | 0.95 (0.66 to 1.38), 0.803 | 0.92 (0.65 to 1.30), 0.625 | 0.71 (0.47 to 1.09), 0.122 |
| Length of pregnancy | |||
| <37 weeks | 0.88 (0.52 to 1.48), 0.631 | 1.12 (0.68 to 1.85), 0.661 | 0.35 (0.16 to 0.78), 0.010 |
| Not known | 0.65 (0.46 to 0.93), 0.019 | 0.97 (0.70 to 1.35), 0.859 | 0.93 (0.64 to 1.35), 0.703 |
| Duration of breast feeding | |||
| ⩽1 month | 0.66 (0.45 to 0.97), 0.036 | 1.00 (0.71 to 1.41), 0.991 | 0.71 (0.47 to 1.07), 0.105 |
| Not known | 1.18 (0.72 to 1.94), 0.507 | 1.04 (0.63 to 1.73), 0.864 | 0.95 (0.54 to 1.68), 0.859 |
| No of household belongings | 0.93 (0.79 to 1.11), 0.438 | 1.00 (0.85 to 1.19), 0.972 | 0.88 (0.73 to 1.07), 0.196 |
| Adult BMI (kg/m2) | 1.04 (1.01 to 1.08), 0.023 | 1.00 (0.97 to 1.04), 0.872 | 1.03 (0.99 to 1.07), 0.195 |