2.5 Analyses
SPSS 24.0 was used to calculate the incidence rates of the clinical
characteristics. The percentage of distribution of causes/medical
history of each group was expressed by the percentage of ascertained
causes/ medical history of each group to the total number of causes/
medical history of each group. The chisquare (X2) test was used to
evaluate the variable. Statistical significance was defined as a
two-tailed P-value less than 0.05.