Table 3. Demographics for family subsamples (%).

Demographic Variable		Longevous Families	Ordinary elderly Families
Gender	Male	58.1	55.1
	Female	41.9	44.9
Age	Mean (SD)	50.49 (17.74)	50.46 (15.33)
Education	High school and beyond	50.3	62.8
	Basic education	43.3	33.8
	No schooling	6.4	3.4
Marital Status	Married	81.0	86.1
	Widowed	4.3	7.1
	Divorced	0	1.3
	Single and others	14.7	5.5
Health Status	Good	90.6	82.8
	Generally good	8.3	15.5
	Poor	1.1	1.7
Habits	Smoking	28.5	34.0
	Drinking	34.9	41.7
Household Income	≤ RMB 2000	63.7	61.7
	≥ RMB 2000	36.3	38.3

Note: Statistical indicators were valid percentages (Longevous families information was unreported for marital status of 2, the health status of 6, the household income of 18; ordinary elderly families information was unreported for marital status of 9, the health status of 14, the habits of 11, the household income of 24); Chi-square tests were used to compare the differences of the rate, age differences in continuous variables were tested using t-test.