Table 3. Relationship between the birth season and prevalence of allergic diseases.
| Birth season | Symptom, eve | Symptom, recent 1 yr | Diagnosis, ever | Treatment, recent 1 yr | ||||
|---|---|---|---|---|---|---|---|---|
| aOR† (95% CI) | P value | aOR† (95% CI) | P value | aOR† (95% CI) | P value | aOR† (95% CI) | P value | |
| Asthma* | 0.82 (0.65–1.03) | 0.094 | 1.01 (0.66–1.55) | 0.960 | 0.83 (0.63–1.10) | 0.200 | 0.83 (0.53–1.30) | 0.418 |
| Allergic rhinitis* | 1.02 (0.87–1.20) | 0.820 | 1.40 (0.96–2.05) | 0.079 | 1.15 (0.97–1.36) | 0.105 | 1.17 (0.98–1.41) | 0.084 |
| Atopic dermatitis* | 1.24 (1.03–1.49) | 0.024 | 1.24 (0.88–1.75) | 0.223 | 1.14 (0.96–1.35) | 0.125 | 1.01 (0.81–1.28) | 0.900 |
| Food allergy* | 1.01 (0.81–1.25) | 0.943 | 1.56 (1.09–2.24) | 0.016 | 1.02 (0.73–1.42) | 0.900 | 1.02 (0.58–1.78) | 0.954 |
Parent's allergic disease includes asthma, allergic rhinitis, atopic dermatitis, and food allergy.
aOR, adjusted odds ratio; CI, confidence interval; Summer, April to September; Winter, October to March.
*Born in winter (reference: summer). †Odds ratios are calculated with adjustment by sex, age, body mass index, type of delivery, use of antibiotics before the age of 12 months, duration of breast feeding, and parental history of allergic diseases.