Relationship between respiratory illness in 1988 and asthma and hay fever in 1995
| Exposure | Proportion of children with asthma among exposed (%) | Proportion of children with asthma among unexposed (%) | Relative risk (95% CI) for asthma | Relative risk (95% CI) adjusted for family history of asthma | Adjusted2-150 relative risk (95% CI) for asthma |
|---|---|---|---|---|---|
| Early URTI by home interview | 38.7% (122/315) | 28.8% (156/542) | 1.35 (1.11 to 1.63) | 1.30 (1.18 to 1.57) | 1.27 (1.05 to 1.53) |
| Antibiotic use by home interview | 35.1% (40/114) | 31.8% (236/742) | 1.10 (0.84 to 1.45) | 1.04 (0.80 to 1.36) | 1.04 (0.78 to 1.37) |
| URTI by telephone interview | 32.2% (151/469) | 31.1% (111/355) | 1.03 (0.84 to 1.26) | 0.97 (0.79 to 1.19) | 0.96 (0.78 to 1.18) |
| LRTI by telephone interview | 41.1% (37/90) | 30.7% (226/735) | 1.34 (1.02 to 1.75) | 1.27 (0.98 to 1.66) | 1.27 (0.97 to 1.66) |
| Exposure | Proportion of children with hay fever among exposed (%) | Proportion of children with hay fever among unexposed (%) | Relative risk (95% CI) for hay fever | Relative risk (95% CI) adjusted for family history of asthma | Adjusted2-150 relative risk (95% CI) for hay fever |
| Early URTI by home interview | 20.6% (66/321) | 17.8% (97/544) | 1.15 (0.87 to 1.53) | 1.12 (0.85 to 1.49) | 1.04 (0.78 to 1.40) |
| Antibiotic use by home interview | 20.5% (24/117) | 18.5% (138/747) | 1.11 (0.75 to 1.64) | 1.07 (0.73 to 1.57) | 0.95 (0.62 to 1.44) |
| URTI by telephone interview | 19.2% (91/474) | 18.5% (66/357) | 1.04 (0.78 to 1.38) | 0.99 (0.75 to 1.33) | 0.92 (0.68 to 1.23) |
| LRTI by telephone interview | 26.7% (24/90) | 17.9% (133/742) | 1.49 (1.02 to 2.17) | 1.42 (0.98 to 2.07) | 1.26 (0.85 to 1.87) |
↵2-150 Adjusted for family history of asthma, exclusive breast feeding at home visit, maternal postnatal smoking, other adult household resident smoking, low birth weight (<2500 g), prematurity (<37 weeks gestation), gas heater in living room, number of household residents in 1995, and age at interview in postnatal weeks. URTI = upper respiratory tract infection; LRTI = lower respiratory tract infection.