Table 2.
Work-related characteristics of the study subjects
| Variables | Category | Control n = 8855 |
Insomnia n = 883 |
|---|---|---|---|
| Type of job* | Administrative | 774 (8.7) | 50 (5.7) |
| Fire suppression | 2822 (31.9) | 308 (34.9) | |
| EMS/rescue | 3185 (36.0) | 318 (36.0) | |
| Others | 2074 (23.4) | 207 (23.4) | |
| Employment period, years* | < 5 | 2914 (43.1) | 230 (36.6) |
| 5–9 | 2014 (29.8) | 186 (29.6) | |
| 10–14 | 1254 (18.5) | 141 (22.4) | |
| ≥ 15 | 584 (8.6) | 72 (11.5) | |
| Work schedule | Day work | 921 (10.4) | 77 (8.7) |
| 3-day cycle | 621 (7.0) | 55 (6.2) | |
| 9-day cycle | 1069 (12.1) | 119 (13.5) | |
| 21-day cycle | 5758 (65.0) | 576 (65.2) | |
| Others | 486 (5.5) | 56 (6.3) | |
| Frequency of emergency events, times per week* | < 5 | 2694 (30.4) | 183 (20.7) |
| 5–9 | 2094 (23.6) | 188 (21.3) | |
| 10–19 | 2269 (25.6) | 254 (28.8) | |
| 20–39 | 1452 (16.5) | 202 (22.9) | |
| ≥ 40 | 336 (3.8) | 56 (6.3) | |
| Frequency of off-duty work, times per month* | < 1 | 4097 (46.3) | 307 (34.8) |
| 1–2 | 3796 (42.9) | 423 (47.9) | |
| 3–4 | 718 (8.1) | 108 (12.2) | |
| ≥ 5 | 244 (2.8) | 45 (5.1) |
EMS means emergency medical service
*p < 0.05