Table 1 Characteristics of participants

Age (mean (SD), years)

72.9 (5.92)

73.5 (6.33)

72.8 (5.89)

73.5 (6.32)

GDS scores (Mean (SD))

3.45 (3.340)

3.61 (3.359)

2.91 (2.638)

3.07 (2.656)

GDS scores

n (%)

n (%)

n (%)

n (%)

 0

2,375 (14.2)

2,165 (10.7)

2,196 (18.5)

1,966 (15.4)

 1

2,587 (15.5)

2,747 (13.6)

2,346 (19.8)

2,514 (19.7)

 2

2,143 (12.9)

2,386 (11.8)

1,953 (16.5)

2,150 (16.8)

 3

1,556 (9.3)

1,804 (8.9)

1,400 (11.8)

1,617 (12.7)

 4

1,204 (7.2)

1,351 (6.7)

1,079 (9.1)

1,232 (9.7)

 5

892 (5.4)

1,011 (5.0)

784 (6.6)

910 (7.1)

 6

718 (4.3)

753 (3.7)

654 (5.5)

675 (5.3)

 7

565 (3.4)

616 (3.1)

501 (4.2)

547 (4.3)

 8

439 (2.6)

505 (2.5)

386 (3.3)

454 (3.6)

 9

366 (2.2)

434 (2.2)

315 (2.7)

388 (3.0)

 10

283 (1.7)

340 (1.7)

255 (2.1)

310 (2.4)

 11

242 (1.5)

291 (1.4)

 12

193 (1.2)

233 (1.2)

 13

142 (0.9)

171 (0.8)

 14

105 (0.6)

123 (0.6)

 15

50 (0.3)

36 (0.2)

 Unknown

2,809 (16.9)

5,205 (25.8)

Medical treatment

n (%)

n (%)

n (%)

n (%)

 Cancer, cardiovascular disease or apoplexy

3,561 (21.4)

2,967 (14.7)

2,408 (20.3)

1,772 (13.9)

 None or unknown

13,108 (78.6)

17,204 (85.3)

9,461 (79.7)

10,991 (86.1)

Basic activities of daily living

n (%)

n (%)

n (%)

n (%)

 Independent

15,560 (93.3)

18,938 (93.9)

11,869 (100)

12,763 (100)

 Needs help

394 (2.4)

732 (3.6)

 Unknown

715 (4.3)

501 (2.5)

Marital status

n (%)

n (%)

n (%)

n (%)

 Married^a

14151 (84.9)

10878 (53.9)

10673 (89.9)

7552 (59.2)

 Widowed (<1 year)

263 (1.6)

855 (4.2)

179 (1.5)

477 (3.7)

 Widowed (≥1 year)

1133 (6.8)

6255 (31.0)

739 (6.2)

4047 (31.7)

 Divorced

251 (1.5)

539 (2.7)

175 (1.5)

350 (2.8)

 Unmarried

145 (0.9

504 (2.5)

103 (0.9)

337 (2.6)

 Unknown

726 (4.0)

1140 (6.0)

Live alone

n (%)

n (%)

n (%)

n (%)

 Yes

824 (4.9)

3028 (15.0)

542 (4.6)

1831 (14.3)

 No

15845 (95.1)

17143 (85.0)

11327 (95.4

10932 (85.7)

Equivalent income (Japanese Yen)

n (%)

n (%)

n (%)

n (%)

 <1 million

1244 (7.5)

2199 (10.9)

766 (6.5)

1,368 (10.7)

 1 - 4 million

7097 (42.6)

6284 (31.2)

5,471 (46.1)

4,652 (36.4)

 ≥4 million

919 (5.5)

835 (4.1)

743 (6.3)

675 (5.3)

 Unknown

7409 (44.4)

10853 (53.8)

4,889 (41.2)

6,068 (47.5)

Years of schooling

n (%)

n (%)

n (%)

n (%)

 <6 years

328 (2.0)

838 (4.2)

166 (1.4)

434 (3.4)

 6 - 9 years

8325 (49.9)

10676 (52.9)

5,701 (48.0)

6,616 (51.8)

 10 - 12 years

5053 (30.3)

6508 (32.3)

3,849 (32.4)

4,440 (34.8)

 ≥13 years

2629 (15.8)

1545 (7.7)

2,040 (17.2)

1,091 (8.5)

 Unknown

334 (2.0)

604 (3.0)

113 (1.0)

182 (1.0)

Social supports

%

%

%

%

  from partner^a

78.1

66.0

80.0

69.2

  from children

29.2

50.4

30.4

53.5

  from outside family

24.5

43.3

26.1

46.3

Giving emotional support

  to partner^a

75.7

55.2

77.6

58.0

  to children

32.6

41.9

35.0

45.6

  to outside family

28.1

48.5

30.5

52.8

Receiving instrumental support

  from partner^a

92.2

76.8

93.2

79.1

  from children

40.2

63.9

41.9

67.2

  from outside family

3.2

8.5

3.4

9.1

Giving instrumental support

  to partner^a

91.7

88.4

93.3

90.4

  to children

40.1

55.1

43.0

60.7

  to outside family

8.0

17.1

8.5

18.9