Statistical analysis
Comparisons between the constipation group and non-constipation group
were demonstrated by using absolute standardized differences (ASD). When
the absolute standardized differences were less than 0.1, the
characteristics of the two groups were deemed to be
similar.21 Kaplan-Meier analysis was performed to
evaluate the cumulative incidence of atopic dermatitis and log-rank test
was utilized to test the significance. Cox proportional hazard model was
applied to estimate the hazard ratio of atopic dermatitis between the
constipation group and non-constipation group. Analyses were performed
using statistical software SPSS version 18.0.