Relationship of infection with asthma, allergic rhinitis/conjunctivitis, and atopic dermatitis: multivariable analysis
Multivariable analyses were performed to investigate the effects of early daycare attendance, older siblings, and severe airway infection on asthma development (Table 2a). The strength of the negative association between daycare attendance and asthma has been noted to decrease with increasing age; the adjusted odds ratio (OR) of daycare attendance showed a significant inverse association with asthma between 5.5 and 9 years (0.74 and 0.83, respectively), and this significant reduction in the risk of asthma disappeared after 10 years (Figure 1A). The association between older siblings and asthma was negative at 10 and 11 years (ORs, 0.90 and 0.90) (Figure S2A). On the contrary, the association between the history of hospitalization due to cold/bronchitis/bronchiolitis/pneumonia and asthma was positive throughout childhood (ORs between 5.5 and 11 years, 1.66–1.82) (Figure 2A).
For allergic rhinitis/conjunctivitis, early daycare attendance (ORs between 5.5 and 11 years, 0.74–0.85) (Figure 1B) and older siblings (ORs between 5.5 and 11 years, 0.66–0.69) (Figure S2B) showed inverse associations with its incidence throughout childhood (Table 2b). The association of a history of hospitalization due to cold/bronchitis/bronchiolitis/pneumonia with allergic rhinitis/conjunctivitis was found to be positive at the age of 8, 9, 11 years (ORs, 1.17–1.22) (Figure 2B). On the other hand, daycare attendance and older siblings were identified to be risks for the development of atopic dermatitis at the age of 5.5 and 7 years. (Figures 1C and S2C) (Table 2c).