(c) people in normal marital status excluding those who were divorced or bereaved as it could be difficult to evaluate their SQOL; (d) people who did not have mental diseases and who could communicate with each other; (e) people who understood the purpose of this study and gave written consent to participate in this study. The minimum sample size was calculated to be 160 when the multiple regression analysis was conducted using G*Power 3.1.2 analysis software with predictor variables set at 8, level of significance at .05, effect size at .15, and test power calculation at .95 [27]. Therefore, the 367 participants who participated in this research, excluding the 10 whose responses were insufficient among the 377 through docu- ment investigation, was considered suitable.