Table 1.
Demographic characteristics of the participants
| n (%) | |
| Gender | |
| Women | 6446 (41.7) |
| Men | 9008 (58.3) |
| Age (years) | |
| 15–29 | 2326 (15.1) |
| 30–39 | 3024 (19.6) |
| 40–49 | 4021 (26.0) |
| 50–59 | 3301 (21.4) |
| 60–79 | 2782 (18.0) |
| Annual household income (yen) | |
| Less than 4 000 000 | 3817 (24.7) |
| 4 000 000–599 999 999 | 3279 (21.2) |
| 6 000 000–899 999 999 | 2349 (15.2) |
| 8 000 000 and higher | 3522 (22.8) |
| Unknown | 2487 (16.1) |
| Employment pattern | |
| Permanent employee | 8666 (56.0) |
| Company executive | 847 (5.5) |
| Temporary employee | 1338 (8.7) |
| Part-time employee | 2870 (18.6) |
| Self-employed | 1733 (11.2) |
| Labour type | |
| Blue-collar job | 4163 (26.9) |
| White-collar job | 7498 (48.6) |
| Other | 3793 (24.5) |
| Underlying disease | |
| Hypertension | 2369 (15.3) |
| Diabetes | 848 (5.5) |
| Asthma | 549 (3.6) |
| Bronchitis | 220 (1.4) |
| Atopic dermatitis | 797 (5.2) |
| Periodontal disease | 1837 (11.9) |
| Caries | 1688 (10.9) |
| Ear disease | 173 (1.1) |
| Angina | 212 (1.4) |
| Myocardial infarction | 156 (1.0) |
| Stroke | 131 (0.8) |
| Chronic obstructive pulmonary disease | 128 (0.8) |
| Cancer | 238 (1.5) |
| Chronic pain | 1557 (10.1) |
| Depression | 583 (3.8) |
| Other mental health problem | 543 (3.5) |