Table 1.
Demographic data for participants (n = 3,867)
| Mean (SD) or % | ||||||
|---|---|---|---|---|---|---|
| All (n = 3,867) | Men (n = 2,512) | Women (n = 1,355) | ||||
| Footnote. SD: standard deviation. PSQI-J: Pittsburgh Sleep Quality Index (Japanese version). | ||||||
| Age (years) | 42.7 | (11.0) | 44.2 | (10.7) | 40.0 | (11.0) |
| Job tenure (years) | 13.6 | (10.6) | 14.7 | (10.9) | 11.4 | (9.5) |
| Year of experience (years) | 9.0 | (8.4) | 9.2 | (8.7) | 8.6 | (7.9) |
| Working hours (hours) | 10.1 | (1.4) | 10.4 | (1.4) | 9.6 | (1.2) |
| Daily rest period (hours) | 13.9 | (1.4) | 13.6 | (1.4) | 14.4 | (1.2) |
| PSQI-J score | 5.8 | (2.9) | 5.7 | (2.8) | 6.0 | (2.9) |
| Sleep duration (hours) | 6.5 | (1.1) | 6.5 | (1.1) | 6.6 | (1.1) |
| Leisure time (hours) | 6.0 | (1.7) | 5.7 | (1.7) | 6.6 | (1.7) |
| Round-trip commute time (hours) | 1.4 | (1.0) | 1.4 | (1.0) | 1.2 | (0.9) |
| Start of working hours | 8.3 | (0.8) | 8.3 | (0.8) | 8.5 | (0.7) |
| End of working hours | 18.4 | (1.3) | 18.6 | (1.3) | 18.1 | (1.1) |
| Bedtime | 23.7 | (1.1) | 23.7 | (1.2) | 23.7 | (1.1) |
| Wake-up time | 6.3 | (0.9) | 6.2 | (0.9) | 6.3 | (0.9) |
| Smoking status (Current smoker) | 26% | 20% | 6% | |||
| Frequency of alcohol drinking | ||||||
| almost never | 46% | 26% | 20% | |||
| 1-2/3-5/6 days (per week) | 22/11/21% | 15/8/17% | 8/3/4% | |||
| Industry types | ||||||
| Agriculture and forestry | 1% | 2% | 1% | |||
| Construction | 10% | 8% | 13% | |||
| Manufacturing | 20% | 20% | 21% | |||
| Information and communications | 5% | 4% | 5% | |||
| Transport and postal activities | 4% | 4% | 4% | |||
| Wholesale and retail trade | 16% | 18% | 14% | |||
| Finance and insurance | 3% | 4% | 3% | |||
| Real estate and goods rental and leasing | 3% | 3% | 3% | |||
| Scientific research, professional, and technical services | 4% | 4% | 4% | |||
| Accommodations, eating, and drinking services | 3% | 3% | 2% | |||
| Living-related and personal services and amusement services | 3% | 3% | 3% | |||
| Education, learning support | 5% | 6% | 4% | |||
| Medical, health care, and welfare | 12% | 12% | 13% | |||
| Compound services | 1% | 1% | 1% | |||
| Services, not elsewhere classified | 6% | 7% | 5% | |||
| Government, except elsewhere classified | 4% | 4% | 4% | |||