Table 1 Characteristics of the study participants

Gender

Male

1621

49.0 %

Female

1687

51.0 %

Age

20–29 years

797

24.1 %

30–39

842

25.5 %

40–49

837

25.3 %

50–59

832

25.2 %

Education

High school

1066

32.2 %

Junior college/vocational school

905

27.4 %

University/graduate school

1337

40.4 %

Marital status

Married

1960

59.3 %

Unmarried

1184

35.8 %

Divorced/widowed

164

5.0 %

Occupation

No occupation

770

23.3 %

Temporary or part-time job

560

16.9 %

Full-time job

1978

59.8 %

Household income

<2.0 million yen ^a

363

11.0 %

2.0–3.9 million

777

23.5 %

4.0–5.9 million

937

28.3 %

6.0–7.9 million

618

18.7 %

8.0–9.9 million

347

10.5 %

10.0+ million

266

8.0 %

Medical condition

No disease

2449

73.6 %

Any disease

879

26.4 %