Multiple logistic regression model for relation of PD20 ⩽1 mg to specific IgE and other factors for 757 subjects
| Factor | Odds ratio | 95% confidence interval | p value |
|---|---|---|---|
| Total IgE (log10 kU/l) | 1.34 | 0.90 to 1.99 | 0.16 |
| Specific IgE to: | |||
| Cat | 2.71 | 1.22 to 6.06 | 0.02 |
| D pteronyssinus (just positive) | 2.16 | 1.20 to 3.89 | 0.01 |
| per 10 kU/l increase above 0.35 | 1.18 | 0.90 to 1.55 | 0.22 |
| Timothy grass | 3.21 | 1.84 to 5.57 | <0.001 |
| Cladosporium | 8.79 | 2.43 to 31.77 | 0.001 |
| Birch | 0.26 | 0.09 to 0.74 | 0.01 |
| (FEV1 - predicted)/RSD | 0.53 | 0.39 to 0.72 | <0.001 |
| FEV1%FVC | 0.90 | 0.86 to 0.94 | <0.001 |
| Per 10 cm of height | 0.52 | 0.36 to 0.75 | 0.001 |
| Females - males | 1.53 | 0.77 to 3.05 | 0.22 |
| Centre: | 0.003 | ||
| Ipswich-Cambridge | 0.42 | 0.23 to 0.76 | |
| Norwich-Cambridge | 0.40 | 0.22 to 0.71 | |
| Parental atopy | 1.76 | 1.10 to 2.82 | 0.02 |
| Season of testing: | 0.60 | ||
| Spring-winter | 0.72 | 0.35 to 1.47 | |
| Summer-winter | 0.84 | 0.42 to 1.65 | |
| Autumn-winter | 1.13 | 0.50 to 2.54 | |
| Number of siblings | 0.02 | ||
| 1 - none | 0.48 | 0.23 to 1.02 | |
| 2 - none | 0.29 | 0.13 to 0.65 | |
| 3 - none | 0.44 | 0.19 to 1.06 | |
| 4 - none | 0.25 | 0.10 to 0.61 | |
| Smoking: difference at age 20 from non-smoker | |||
| Ex-smoker | 0.94 | 0.20 to 4.39 | 0.94 |
| Current smoker | 0.36 | 0.11 to 1.16 | 0.09 |
| Age/smoking: per 10 years of age in | |||
| Non-smokers | 0.47 | 0.23 to 0.78 | 0.003 |
| Ex-smokers | 0.54 | 0.23 to 1.26 | 0.16 |
| Smokers | 1.20 | 0.63 to 2.26 | 0.58 |
RSD = residual standard deviation in prediction model for FEV1.