2.6. Statistical analysis
All sociodemographic statistics were analyzed using Stata 17.0. Continuous variables were described using means (95% confidence intervals) and tested using a two independent samples t-test (for continuous variables which are normal distribution, such as parents' age). Discrete variables were described using n (%) and tested using a two independent samples chi-square test (for categories variables without ranks) and Wilcoxon test (for categories variables with ranks).SNA, which was completed by Ucinet 6, includes both ego network analysis and whole network analysis (