Table 1.

Sociodemographic and clinical characteristics of the study population

	40-59 yr		≥60 yr		p a
	(No. participants = 88,749)		(No. participants = 67,998)
	n	%	n	%
Gender
Men	42,961	48.41	28,734	42.26	<0.001
Women	45,788	51.59	39,264	57.74
Marital status
With spouse	72,945	82.19	43,552	64.05	<0.001
Separated	4459	5.02	1746	2.57
Divorced	4698	5.29	1081	1.59
Widowed	3474	3.91	21,286	31.3
Never married	3173	3.58	333	0.49
Employment
No	4527	5.1	22,956	33.76	<0.001
Yes	84,170	94.84	45,029	66.22
Unknown	52	0.06	13	0.02
Occupational categories
Manual	31,572	35.57	21,798	32.06	<0.001
Non-manual	33,635	37.9	5012	7.37
Unemployed/otherb	23,490	26.47	41,175	60.55
Unknown	52	0.06	13	0.02
Education
College or more	19,617	22.1	3384	4.98	<0.001
High school	36,308	40.91	8389	12.34
Middle school	16,603	18.71	8492	12.49
Elementary School	13,192	14.86	23,112	33.99
Non-educated	3029	3.41	24,621	36.21
Income (Korean 10,000won/month)c
4.01 million won or more	17,966	20.24	4418	6.5	<0.001
4 million won or less	11,184	12.6	3097	4.55
3 million won or less	20,672	23.29	7242	10.65
2 million won or less	21,260	23.96	13,571	19.96
1 million won or less	14,562	16.41	37,459	55.09
Unknown	3105	3.5	2211	3.25
Residence locationd
County	27,708	31.22	32,409	47.66	<0.001
Small city	26,235	29.56	17,741	26.09
Middle city	9543	10.75	4137	6.08
Metropolitan	25,263	28.47	13,711	20.16
No. of chronic diseases
0	57,127	64.37	16,685	24.54	<0.001
1	21,076	23.75	19,853	29.2
2	7351	8.28	15,520	22.82
3	2332	2.63	9505	13.98
4  or more	863	0.97	6435	9.46
Multiple chronic diseases
No (chronic diseases 0–1)	78,203	88.12	36,538	53.73	<0.001
Yes (chronic diseases ≥2)	10,546	11.88	31,460	46.27
Depressive symptoms
No (CES-D-Ke 0–15)	80,234	90.41	56,219	82.68	<0.001
Yes (CES-D-Ke ≥ 16)	8515	9.59	11,779	17.32
CES-D-K (median, IQR)	3	1-3	5	2-12	<0.001
Depression diagnosed by physicians
No	86,291	97.23	65,567	96.42	<0.001
Yes	2458	2.77	2431	3.58

^aP-values were obtained using the chi-square or Mann Whitney U test with the CES-D-K scores

^bIncluding housewives

^cOne thousand won roughly equals one US dollar

^dCounty; population less than 50,000

Small city; population more than 50,000

Middle city; population more than 500,000

Metropolitan; population more than 1,000,000

^eCES-D-K; Korean version of the Center for Epidemiological Studies Depression