Table 1.

Socio-demographic characteristics of the study population (N = 3,911) by mental health status.

Variables	Total sample (N = 3,911)		Those with good mental health (N = 3,547)		Those with poor mental health (N = 364)		Statistics
	n	%	n	%	n	%	X2	df	P
Age (years)							1.77	2	0.412
65–74 (mean age: 68.64 ± 2.74)	2,754	70.4	2,488	70.1	266	73.1
75–84 (mean age: 78.73 ± 2.80)	989	25.3	903	25.5	86	23.6
≥ 85 (mean age: 87.42 ± 2.56)	168	4.3	156	4.4	12	3.3
Male	1,892	48.4	1,765	49.8	127	34.9	29.23	1	<0.001
Married/cohabiting	3,036	77.6	2,771	78.1	265	72.8	5.38	1	0.020
Urban area	826	21.1	778	21.9	48	13.2	15.16	1	<0.001
Education level							19.21	1	<0.001
Primary school or belowa	2,640	67.5	2,357	66.5	283	77.7
Secondary school or higher	1,271	32.5	1,190	33.5	81	22.3
Unemployed	1,379	35.3	1,268	35.7	111	30.5	3.99	1	0.046
Low incomeb	3,016	77.1	2,695	76.0	321	88.2	27.88	1	<0.001
Living alone	642	16.4	568	16.0	74	20.3	4.48	1	0.034
Religious beliefs	268	6.9	241	6.8	27	7.4	0.20	1	0.654
Health insurance	3,822	97.7	3,467	97.7	355	97.5	0.70	1	0.791
Major medical conditionsc	2,572	65.8	2,264	63.8	308	84.6	63.35	1	<0.001
Family history of psychiatric disorders	70	1.8	51	1.4	19	5.2	26.86	1	<0.001
	Mean	SD	Mean	SD	Mean	SD	T	df	P
Age (years)	72.00	6.09	72.05	6.13	71.56	5.76	1.44	3,909	0.126

Bolded values: <0.05; M, mean; SD, standard deviation.

Good mental health was defined as the 12-item General Health Questionnaire (GHQ-12) <4.

^aLower education = <7 years of education.

^bLow income: annual household income < RMB 30,000 (~USD 4,242).

^cMajor medical conditions included hypertension, diabetes, cerebrovascular disease, cancer, and gastrointestinal diseases.