Table 1 Distribution of participant characteristics (number with percent) according to education and income levels

Male sex

4858 (51.3%)

9881 (51.7%)

2454 (35.8%)

2311 (75.4%)

< 0.0001

5913 (45.5%)

8659 (54.2%)

3274 (52.3%)

1658 (50.7%)

< 0.0001

  < 50

476 (5.0%)

4919 (25.8%)

2345 (34.2%)

904 (29.5%)

< 0.0001

2116 (16.3%)

4122 (25.8%)

1712 (27.3%)

694 (21.2%)

< 0.0001

 50–59

1530 (16.1%)

6537 (34.2%)

2634 (38.4%)

1104 (36.0%)

3049 (23.5%)

4801 (30.1%)

2554 (40.8%)

1401 (42.8%)

 60–69

5108 (53.9%)

6242 (32.7%)

1612 (23.5%)

843 (27.5%)

5749 (44.3%)

5491 (34.4%)

1616 (25.8%)

949 (29.0%)

  ≥ 70

2364 (24.9%)

1400 (7.3%)

268 (3.9%)

213 (7.0%)

2072 (16.0%)

1561 (9.8%)

383 (6.1%)

229 (7.0%)

 Married

7486 (79.8%)

15,517 (81.6%)

5530 (80.9%)

2532 (83.0%)

< 0.0001²

8877 (69.0%)

13,386 (84.2%)

5701 (91.3%)

3101 (94.9%)

< 0.0001²

 Never married

552 (5.9%)

1518 (8.0%)

569 (8.3%)

310 (10.2%)

1597 (12.4%)

1084 (6.8%)

223 (3.6%)

45 (1.4%)

 Divorced, separated, or bereaved

1348 (14.4%)

1976 (10.4%)

736 (10.8%)

209 (6.9%)

2399 (18.6%)

1428 (9.0%)

321 (5.1%)

121 (3.7%)

 Junior high school

–

–

–

–

4879 (37.6%)

3353 (21.0%)

825 (13.2%)

421 (12.9%)

< 0.0001

 High school

–

–

–

–

5807 (44.7%)

8468 (53.0%)

3259 (52.0%)

1564 (47.8%)

 Junior college

–

–

–

–

1777 (13.7%)

2990 (18.7%)

1364 (21.8%)

728 (22.2%)

 University or higher

–

–

–

–

523 (4.0%)

1164 (7.3%)

817 (13.0%)

560 (17.1%)

 0–2,990,000

4879 (51.5%)

5807 (30.4%)

1777 (25.9%)

523 (17.1%)

< 0.0001

–

–

–

–

 3,000,000-5,990,000

3353 (35.4%)

8468 (44.3%)

2990 (43.6%)

1164 (38.0%)

–

–

–

–

 6,000,000-8,990,000

825 (8.7%)

3259 (17.1%)

1364 (19.9%)

817 (26.7%)

–

–

–

–

  ≥ 9,000,000

421 (4.4%)

1564 (8.2%)

728 (10.6%)

560 (18.3%)

–

–

–

–

 Sales and service

1331 (14.2%)

3683 (19.4%)

1413 (20.7%)

439 (14.4%)

< 0.0001³

2404 (18.7%)

3079 (19.4%)

930 (15.0%)

453 (13.9%)

< 0.0001³

 Office work

117 (1.3%)

1957 (10.3%)

691 (10.1%)

368 (12.1%)

617 (4.8%)

1203 (7.6%)

845 (13.6%)

468 (14.4%)

 Professional

1224 (13.0%)

3616 (19.1%)

2550 (37.4%)

1310 (42.9%)

1476 (11.5%)

3865 (24.4%)

2098 (33.7%)

1261 (38.8%)

 Manual

2648 (28.2%)

4863 (25.6%)

705 (10.3%)

245 (8.0%)

3020 (23.4%)

3679 (23.2%)

1187 (19.1%)

575 (17.7%)

 No job or others

4066 (43.3%)

4853 (25.6%)

1463 (21.5%)

689 (22.6%)

5374 (41.7%)

4040 (25.5%)

1161 (18.7%)

496 (15.3%)

 Murakami

2791 (29.5%)

6195 (32.4%)

1754 (25.6%)

750 (24.5%)

< 0.0001

4078 (31.4%)

4650 (29.1%)

1851 (29.6%)

911 (27.8%)

< 0.0001

 Uonuma

6687 (70.6%)

12,903 (67.6%)

5105 (74.4%)

2314 (75.5%)

8908 (68.6%)

11,325 (70.9%)

4414 (70.5%)

2362 (72.2%)

 Cancer

770 (8.1%)

1144 (6.0%)

384 (5.6%)

185 (6.0%)

< 0.0001

941 (7.3%)

975 (6.1%)

368 (5.9%)

199 (6.1%)

0.0002

 Myocardial infarction

80 (0.8%)

107 (0.6%)

23 (0.3%)

20 (0.7%)

0.0035

91 (0.7%)

93 (0.6%)

27 (0.4%)

19 (0.6%)

0.0722

 Stroke

266 (2.8%)

352 (1.8%)

91 (1.3%)

58 (1.9%)

< 0.0001

365 (2.8%)

273 (1.7%)

88 (1.4%)

41 (1.3%)

< 0.0001

 Diabetes

955 (10.1%)

1238 (6.5%)

334 (4.9%)

213 (7.0%)

< 0.0001

1085 (8.4%)

1058 (6.6%)

392 (6.3%)

205 (6.3%)

< 0.0001

 No disability

8595 (90.7%)

18,215 (95.4%)

6582 (96.0%)

2925(95.5%)

< 0.0001

11,817 (91.0%)

15,221 (95.3%)

6092 (97.2%)

3187(97.4%)

< 0.0001

 Having some disability⁴

809 (8.5%)

823 (4.3%)

261 (3.8%)

129 (4.2%)

1079 (8.3%)

701 (4.4%)

162 (2.6%)

80 (2.4%)

 Physically dependent⁵

74 (0.8%)

60 (0.3%)

16 (0.2%)

10 (0.3%)

90 (0.7%)

53 (0.3%)

11 (0.2%)

6 (0.2%)