Study limitations
Some limitations to this study should be noted. First, this cross-sectional study does not support a conclusion of causality, which shall be explored by future studies of a longitudinal design at the family system level; nor is it impossible to determine the directionality of the relationship among children’s PTSS, parents’ PTSS and depression, and family functioning. Second, only self-reported screening tools were used in this study to measure PTSS. Nevertheless, the purpose of this study is to screen PTSS and determine the severity of PTSS, and the measurement tools have good reliability and validity. Finally, less than 80% of valid questionnaires were recovered in cancer group, indicating that families of children with cancer did not have time to care for anything other than the treatment of the child, and that this group urgently needed adequate psychosocial support.