Table 1.

Comparisons of potential confounders and life satisfaction between the participants with and without depressive symptoms.

Variable	Depressive symptoms		p-value
	No (n = 1,545)	Yes (n = 247)
	Mean (SD) or n (%)	Mean (SD) or n (%)
Demographic characteristics
Age (in years)	69.9 ± 6.2	71.0 ± 6.6	0.017
Gender (ref = male)	714 (46.2)	118 (47.8)	0.648
Education (in years)	11.8 ± 2.4	11.3 ± 2.5	0.006
Household status: living alone (ref = yes)	177 (11.5)	34 (13.8)	0.296
Health factors
Heart disease (ref = yes)	222 (14.4)	38 (15.4)	0.674
Pulmonary disease (ref = yes)	120 (7.8)	29 (11.7)	0.036
Hypertension (ref = yes)	668 (43.2)	121 (49.0)	0.091
Hyperlipidemia (ref = yes)	447 (28.9)	82 (33.2)	0.172
Diabetes mellitus (ref = yes)	178 (11.5)	49 (19.8)	<0.001
Osteoarthritis of the knee (ref = yes)	259 (16.8)	46 (18.6)	0.47
Self-rated health (ref = poor)	159 (10.3)	56 (22.7)	<0.001
Medication (n)	2.3 ± 2.3	3.0 ± 2.8	<0.001
Sleeping pills (ref = yes)	187 (12.1)	38 (15.4)	0.148
Mini-Mental State Examination (score)	27.8 ± 2.2	27.5 ± 2.3	0.069
Life satisfaction items
1) Mental health (ref = poor)	114 (7.4)	73 (29.6)	<0.001
2) Physical health (ref = poor)	192 (12.4)	75 (30.4)	<0.001
3) Housing (ref = poor)	83 (5.4)	23 (9.3)	0.015
4) Community environment (ref = poor)	115 (7.4)	55 (22.3)	<0.001
5) Household finances (ref = poor)	185 (12.0)	73 (29.6)	<0.001
6) Family members (ref = poor)	79 (5.1)	38 (15.4)	<0.001
7) Friends (ref = poor)	96 (6.2)	62 (25.1)	<0.001
8) Neighbors (ref = poor)	179 (11.6)	68 (27.5)	< 0.001
9) Japanese social security (ref = poor)	774 (50.1)	171 (69.2)	<0.001
10) Japanese politics (ref = poor)	816 (52.8)	166 (67.2)	<0.001
11) Social role (ref = poor)	41 (2.7)	32 (13.0)	<0.001
12) Sense of accomplishment (ref = poor)	207 (13.4)	92 (37.2)	<0.001
13) Free time (ref = poor)	77 (5.0)	34 (13.8)	<0.001