Demographic characteristics of study subjects stratified by sleep quality.

aThe unmarried include those who are single, divorced or widowed.bComparison between groups was tested used Student’s t-test for the continuous variables and Pearson’s χ2 test for the categorical variables.Demographic characteristics of study subjects stratified by sleep quality.a. 未婚人群涵盖单身、离异及丧偶者。 b. 组间比较采用Student t检验（Student’s t-test）分析连续变量，采用Pearson卡方检验（Pearson’s χ2 test）分析分类变量。 按睡眠质量分层的研究对象人口学特征。